anno_start anno_end anno_text entity_type sentence section 23 39 Arabinoxylanases protein_type The Mechanism by Which Arabinoxylanases Can Recognize Highly Decorated Xylans* TITLE 54 70 Highly Decorated protein_state The Mechanism by Which Arabinoxylanases Can Recognize Highly Decorated Xylans* TITLE 71 77 Xylans chemical The Mechanism by Which Arabinoxylanases Can Recognize Highly Decorated Xylans* TITLE 29 34 plant taxonomy_domain The enzymatic degradation of plant cell walls is an important biological process of increasing environmental and industrial significance. ABSTRACT 0 5 Xylan chemical Xylan, a major component of the plant cell wall, consists of a backbone of β-1,4-xylose (Xylp) units that are often decorated with arabinofuranose (Araf) side chains. ABSTRACT 32 37 plant taxonomy_domain Xylan, a major component of the plant cell wall, consists of a backbone of β-1,4-xylose (Xylp) units that are often decorated with arabinofuranose (Araf) side chains. ABSTRACT 75 87 β-1,4-xylose chemical Xylan, a major component of the plant cell wall, consists of a backbone of β-1,4-xylose (Xylp) units that are often decorated with arabinofuranose (Araf) side chains. ABSTRACT 89 93 Xylp chemical Xylan, a major component of the plant cell wall, consists of a backbone of β-1,4-xylose (Xylp) units that are often decorated with arabinofuranose (Araf) side chains. ABSTRACT 131 146 arabinofuranose chemical Xylan, a major component of the plant cell wall, consists of a backbone of β-1,4-xylose (Xylp) units that are often decorated with arabinofuranose (Araf) side chains. ABSTRACT 148 152 Araf chemical Xylan, a major component of the plant cell wall, consists of a backbone of β-1,4-xylose (Xylp) units that are often decorated with arabinofuranose (Araf) side chains. ABSTRACT 8 28 penta-modular enzyme protein_type A large penta-modular enzyme, CtXyl5A, was shown previously to specifically target arabinoxylans. ABSTRACT 30 37 CtXyl5A protein A large penta-modular enzyme, CtXyl5A, was shown previously to specifically target arabinoxylans. ABSTRACT 83 96 arabinoxylans chemical A large penta-modular enzyme, CtXyl5A, was shown previously to specifically target arabinoxylans. ABSTRACT 19 36 crystal structure evidence Here we report the crystal structure of the arabinoxylanase and the enzyme in complex with ligands. ABSTRACT 44 59 arabinoxylanase protein_type Here we report the crystal structure of the arabinoxylanase and the enzyme in complex with ligands. ABSTRACT 75 90 in complex with protein_state Here we report the crystal structure of the arabinoxylanase and the enzyme in complex with ligands. ABSTRACT 91 98 ligands chemical Here we report the crystal structure of the arabinoxylanase and the enzyme in complex with ligands. ABSTRACT 95 111 catalytic domain structure_element The data showed that four of the protein modules adopt a rigid structure, which stabilizes the catalytic domain. ABSTRACT 15 56 non-catalytic carbohydrate binding module structure_element The C-terminal non-catalytic carbohydrate binding module could not be observed in the crystal structure, suggesting positional flexibility. ABSTRACT 86 103 crystal structure evidence The C-terminal non-catalytic carbohydrate binding module could not be observed in the crystal structure, suggesting positional flexibility. ABSTRACT 4 13 structure evidence The structure of the enzyme in complex with Xylp-β-1,4-Xylp-β-1,4-Xylp-[α-1,3-Araf]-β-1,4-Xylp showed that the Araf decoration linked O3 to the xylose in the active site is located in the pocket (−2* subsite) that abuts onto the catalytic center. ABSTRACT 28 43 in complex with protein_state The structure of the enzyme in complex with Xylp-β-1,4-Xylp-β-1,4-Xylp-[α-1,3-Araf]-β-1,4-Xylp showed that the Araf decoration linked O3 to the xylose in the active site is located in the pocket (−2* subsite) that abuts onto the catalytic center. ABSTRACT 44 94 Xylp-β-1,4-Xylp-β-1,4-Xylp-[α-1,3-Araf]-β-1,4-Xylp chemical The structure of the enzyme in complex with Xylp-β-1,4-Xylp-β-1,4-Xylp-[α-1,3-Araf]-β-1,4-Xylp showed that the Araf decoration linked O3 to the xylose in the active site is located in the pocket (−2* subsite) that abuts onto the catalytic center. ABSTRACT 111 115 Araf chemical The structure of the enzyme in complex with Xylp-β-1,4-Xylp-β-1,4-Xylp-[α-1,3-Araf]-β-1,4-Xylp showed that the Araf decoration linked O3 to the xylose in the active site is located in the pocket (−2* subsite) that abuts onto the catalytic center. ABSTRACT 144 150 xylose chemical The structure of the enzyme in complex with Xylp-β-1,4-Xylp-β-1,4-Xylp-[α-1,3-Araf]-β-1,4-Xylp showed that the Araf decoration linked O3 to the xylose in the active site is located in the pocket (−2* subsite) that abuts onto the catalytic center. ABSTRACT 158 169 active site site The structure of the enzyme in complex with Xylp-β-1,4-Xylp-β-1,4-Xylp-[α-1,3-Araf]-β-1,4-Xylp showed that the Araf decoration linked O3 to the xylose in the active site is located in the pocket (−2* subsite) that abuts onto the catalytic center. ABSTRACT 188 194 pocket site The structure of the enzyme in complex with Xylp-β-1,4-Xylp-β-1,4-Xylp-[α-1,3-Araf]-β-1,4-Xylp showed that the Araf decoration linked O3 to the xylose in the active site is located in the pocket (−2* subsite) that abuts onto the catalytic center. ABSTRACT 196 207 −2* subsite site The structure of the enzyme in complex with Xylp-β-1,4-Xylp-β-1,4-Xylp-[α-1,3-Araf]-β-1,4-Xylp showed that the Araf decoration linked O3 to the xylose in the active site is located in the pocket (−2* subsite) that abuts onto the catalytic center. ABSTRACT 229 245 catalytic center site The structure of the enzyme in complex with Xylp-β-1,4-Xylp-β-1,4-Xylp-[α-1,3-Araf]-β-1,4-Xylp showed that the Araf decoration linked O3 to the xylose in the active site is located in the pocket (−2* subsite) that abuts onto the catalytic center. ABSTRACT 4 15 −2* subsite site The −2* subsite can also bind to Xylp and Arap, explaining why the enzyme can utilize xylose and arabinose as specificity determinants. ABSTRACT 33 37 Xylp chemical The −2* subsite can also bind to Xylp and Arap, explaining why the enzyme can utilize xylose and arabinose as specificity determinants. ABSTRACT 42 46 Arap chemical The −2* subsite can also bind to Xylp and Arap, explaining why the enzyme can utilize xylose and arabinose as specificity determinants. ABSTRACT 86 92 xylose chemical The −2* subsite can also bind to Xylp and Arap, explaining why the enzyme can utilize xylose and arabinose as specificity determinants. ABSTRACT 97 106 arabinose chemical The −2* subsite can also bind to Xylp and Arap, explaining why the enzyme can utilize xylose and arabinose as specificity determinants. ABSTRACT 0 20 Alanine substitution experimental_method Alanine substitution of Glu68, Tyr92, or Asn139, which interact with arabinose and xylose side chains at the −2* subsite, abrogates catalytic activity. ABSTRACT 24 29 Glu68 residue_name_number Alanine substitution of Glu68, Tyr92, or Asn139, which interact with arabinose and xylose side chains at the −2* subsite, abrogates catalytic activity. ABSTRACT 31 36 Tyr92 residue_name_number Alanine substitution of Glu68, Tyr92, or Asn139, which interact with arabinose and xylose side chains at the −2* subsite, abrogates catalytic activity. ABSTRACT 41 47 Asn139 residue_name_number Alanine substitution of Glu68, Tyr92, or Asn139, which interact with arabinose and xylose side chains at the −2* subsite, abrogates catalytic activity. ABSTRACT 69 78 arabinose chemical Alanine substitution of Glu68, Tyr92, or Asn139, which interact with arabinose and xylose side chains at the −2* subsite, abrogates catalytic activity. ABSTRACT 83 89 xylose chemical Alanine substitution of Glu68, Tyr92, or Asn139, which interact with arabinose and xylose side chains at the −2* subsite, abrogates catalytic activity. ABSTRACT 109 120 −2* subsite site Alanine substitution of Glu68, Tyr92, or Asn139, which interact with arabinose and xylose side chains at the −2* subsite, abrogates catalytic activity. ABSTRACT 14 25 active site site Distal to the active site, the xylan backbone makes limited apolar contacts with the enzyme, and the hydroxyls are solvent-exposed. ABSTRACT 31 36 xylan chemical Distal to the active site, the xylan backbone makes limited apolar contacts with the enzyme, and the hydroxyls are solvent-exposed. ABSTRACT 115 130 solvent-exposed protein_state Distal to the active site, the xylan backbone makes limited apolar contacts with the enzyme, and the hydroxyls are solvent-exposed. ABSTRACT 18 25 CtXyl5A protein This explains why CtXyl5A is capable of hydrolyzing xylans that are extensively decorated and that are recalcitrant to classic endo-xylanase attack. ABSTRACT 52 58 xylans chemical This explains why CtXyl5A is capable of hydrolyzing xylans that are extensively decorated and that are recalcitrant to classic endo-xylanase attack. ABSTRACT 127 140 endo-xylanase protein_type This explains why CtXyl5A is capable of hydrolyzing xylans that are extensively decorated and that are recalcitrant to classic endo-xylanase attack. ABSTRACT 4 9 plant taxonomy_domain The plant cell wall is an important biological substrate. INTRO 53 67 microorganisms taxonomy_domain This complex composite structure is depolymerized by microorganisms that occupy important highly competitive ecological niches, whereas the process makes an important contribution to the carbon cycle. INTRO 15 20 plant taxonomy_domain Given that the plant cell wall is the most abundant source of renewable organic carbon on the planet, this macromolecular substrate has substantial industrial potential. INTRO 45 50 plant taxonomy_domain An example of the chemical complexity of the plant cell wall is provided by xylan, which is the major hemicellulosic component. INTRO 76 81 xylan chemical An example of the chemical complexity of the plant cell wall is provided by xylan, which is the major hemicellulosic component. INTRO 5 19 polysaccharide chemical This polysaccharide comprises a backbone of β-1,4-d-xylose residues in their pyranose configuration (Xylp) that are decorated at O2 with 4-O-methyl-d-glucuronic acid (GlcA) and at O2 and/or O3 with α-l-arabinofuranose (Araf) residues, whereas the polysaccharide can also be extensively acetylated. INTRO 44 58 β-1,4-d-xylose chemical This polysaccharide comprises a backbone of β-1,4-d-xylose residues in their pyranose configuration (Xylp) that are decorated at O2 with 4-O-methyl-d-glucuronic acid (GlcA) and at O2 and/or O3 with α-l-arabinofuranose (Araf) residues, whereas the polysaccharide can also be extensively acetylated. INTRO 77 85 pyranose chemical This polysaccharide comprises a backbone of β-1,4-d-xylose residues in their pyranose configuration (Xylp) that are decorated at O2 with 4-O-methyl-d-glucuronic acid (GlcA) and at O2 and/or O3 with α-l-arabinofuranose (Araf) residues, whereas the polysaccharide can also be extensively acetylated. INTRO 101 105 Xylp chemical This polysaccharide comprises a backbone of β-1,4-d-xylose residues in their pyranose configuration (Xylp) that are decorated at O2 with 4-O-methyl-d-glucuronic acid (GlcA) and at O2 and/or O3 with α-l-arabinofuranose (Araf) residues, whereas the polysaccharide can also be extensively acetylated. INTRO 137 165 4-O-methyl-d-glucuronic acid chemical This polysaccharide comprises a backbone of β-1,4-d-xylose residues in their pyranose configuration (Xylp) that are decorated at O2 with 4-O-methyl-d-glucuronic acid (GlcA) and at O2 and/or O3 with α-l-arabinofuranose (Araf) residues, whereas the polysaccharide can also be extensively acetylated. INTRO 167 171 GlcA chemical This polysaccharide comprises a backbone of β-1,4-d-xylose residues in their pyranose configuration (Xylp) that are decorated at O2 with 4-O-methyl-d-glucuronic acid (GlcA) and at O2 and/or O3 with α-l-arabinofuranose (Araf) residues, whereas the polysaccharide can also be extensively acetylated. INTRO 198 217 α-l-arabinofuranose chemical This polysaccharide comprises a backbone of β-1,4-d-xylose residues in their pyranose configuration (Xylp) that are decorated at O2 with 4-O-methyl-d-glucuronic acid (GlcA) and at O2 and/or O3 with α-l-arabinofuranose (Araf) residues, whereas the polysaccharide can also be extensively acetylated. INTRO 219 223 Araf chemical This polysaccharide comprises a backbone of β-1,4-d-xylose residues in their pyranose configuration (Xylp) that are decorated at O2 with 4-O-methyl-d-glucuronic acid (GlcA) and at O2 and/or O3 with α-l-arabinofuranose (Araf) residues, whereas the polysaccharide can also be extensively acetylated. INTRO 247 261 polysaccharide chemical This polysaccharide comprises a backbone of β-1,4-d-xylose residues in their pyranose configuration (Xylp) that are decorated at O2 with 4-O-methyl-d-glucuronic acid (GlcA) and at O2 and/or O3 with α-l-arabinofuranose (Araf) residues, whereas the polysaccharide can also be extensively acetylated. INTRO 17 21 Araf chemical In addition, the Araf side chain decorations can also be esterified to ferulic acid that, in some species, provide a chemical link between hemicellulose and lignin. INTRO 71 83 ferulic acid chemical In addition, the Araf side chain decorations can also be esterified to ferulic acid that, in some species, provide a chemical link between hemicellulose and lignin. INTRO 139 152 hemicellulose chemical In addition, the Araf side chain decorations can also be esterified to ferulic acid that, in some species, provide a chemical link between hemicellulose and lignin. INTRO 157 163 lignin chemical In addition, the Araf side chain decorations can also be esterified to ferulic acid that, in some species, provide a chemical link between hemicellulose and lignin. INTRO 25 31 xylans chemical The precise structure of xylans varies between plant species, in particular in different tissues and during cellular differentiation. INTRO 47 52 plant taxonomy_domain The precise structure of xylans varies between plant species, in particular in different tissues and during cellular differentiation. INTRO 15 20 plant taxonomy_domain In specialized plant tissues, such as the outer layer of cereal grains, xylans are extremely complex, and side chains may comprise a range of other sugars including l- and d-galactose and β- and α-Xylp units. INTRO 57 63 cereal taxonomy_domain In specialized plant tissues, such as the outer layer of cereal grains, xylans are extremely complex, and side chains may comprise a range of other sugars including l- and d-galactose and β- and α-Xylp units. INTRO 72 78 xylans chemical In specialized plant tissues, such as the outer layer of cereal grains, xylans are extremely complex, and side chains may comprise a range of other sugars including l- and d-galactose and β- and α-Xylp units. INTRO 148 154 sugars chemical In specialized plant tissues, such as the outer layer of cereal grains, xylans are extremely complex, and side chains may comprise a range of other sugars including l- and d-galactose and β- and α-Xylp units. INTRO 165 183 l- and d-galactose chemical In specialized plant tissues, such as the outer layer of cereal grains, xylans are extremely complex, and side chains may comprise a range of other sugars including l- and d-galactose and β- and α-Xylp units. INTRO 188 201 β- and α-Xylp chemical In specialized plant tissues, such as the outer layer of cereal grains, xylans are extremely complex, and side chains may comprise a range of other sugars including l- and d-galactose and β- and α-Xylp units. INTRO 17 23 cereal taxonomy_domain Indeed, in these cereal brans, xylans have very few backbone Xylp units that are undecorated, and the side chains can contain up to six sugars. INTRO 31 37 xylans chemical Indeed, in these cereal brans, xylans have very few backbone Xylp units that are undecorated, and the side chains can contain up to six sugars. INTRO 61 65 Xylp chemical Indeed, in these cereal brans, xylans have very few backbone Xylp units that are undecorated, and the side chains can contain up to six sugars. INTRO 136 142 sugars chemical Indeed, in these cereal brans, xylans have very few backbone Xylp units that are undecorated, and the side chains can contain up to six sugars. INTRO 55 60 plant taxonomy_domain Reflecting the chemical and physical complexity of the plant cell wall, microorganisms that utilize these composite structures express a large number of polysaccharide-degrading enzymes, primarily glycoside hydrolases, but also polysaccharide lyases, carbohydrate esterases, and lytic polysaccharide monooxygenases. INTRO 72 86 microorganisms taxonomy_domain Reflecting the chemical and physical complexity of the plant cell wall, microorganisms that utilize these composite structures express a large number of polysaccharide-degrading enzymes, primarily glycoside hydrolases, but also polysaccharide lyases, carbohydrate esterases, and lytic polysaccharide monooxygenases. INTRO 153 185 polysaccharide-degrading enzymes protein_type Reflecting the chemical and physical complexity of the plant cell wall, microorganisms that utilize these composite structures express a large number of polysaccharide-degrading enzymes, primarily glycoside hydrolases, but also polysaccharide lyases, carbohydrate esterases, and lytic polysaccharide monooxygenases. INTRO 197 217 glycoside hydrolases protein_type Reflecting the chemical and physical complexity of the plant cell wall, microorganisms that utilize these composite structures express a large number of polysaccharide-degrading enzymes, primarily glycoside hydrolases, but also polysaccharide lyases, carbohydrate esterases, and lytic polysaccharide monooxygenases. INTRO 228 249 polysaccharide lyases protein_type Reflecting the chemical and physical complexity of the plant cell wall, microorganisms that utilize these composite structures express a large number of polysaccharide-degrading enzymes, primarily glycoside hydrolases, but also polysaccharide lyases, carbohydrate esterases, and lytic polysaccharide monooxygenases. INTRO 251 273 carbohydrate esterases protein_type Reflecting the chemical and physical complexity of the plant cell wall, microorganisms that utilize these composite structures express a large number of polysaccharide-degrading enzymes, primarily glycoside hydrolases, but also polysaccharide lyases, carbohydrate esterases, and lytic polysaccharide monooxygenases. INTRO 279 314 lytic polysaccharide monooxygenases protein_type Reflecting the chemical and physical complexity of the plant cell wall, microorganisms that utilize these composite structures express a large number of polysaccharide-degrading enzymes, primarily glycoside hydrolases, but also polysaccharide lyases, carbohydrate esterases, and lytic polysaccharide monooxygenases. INTRO 6 33 carbohydrate active enzymes protein_type These carbohydrate active enzymes are grouped into sequence-based families in the CAZy database. INTRO 16 21 xylan chemical With respect to xylan degradation, the backbone of simple xylans is hydrolyzed by endo-acting xylanases, the majority of which are located in glycoside hydrolase (GH)5 families GH10 and GH11, although they are also present in GH8. INTRO 58 64 xylans chemical With respect to xylan degradation, the backbone of simple xylans is hydrolyzed by endo-acting xylanases, the majority of which are located in glycoside hydrolase (GH)5 families GH10 and GH11, although they are also present in GH8. INTRO 82 103 endo-acting xylanases protein_type With respect to xylan degradation, the backbone of simple xylans is hydrolyzed by endo-acting xylanases, the majority of which are located in glycoside hydrolase (GH)5 families GH10 and GH11, although they are also present in GH8. INTRO 142 161 glycoside hydrolase protein_type With respect to xylan degradation, the backbone of simple xylans is hydrolyzed by endo-acting xylanases, the majority of which are located in glycoside hydrolase (GH)5 families GH10 and GH11, although they are also present in GH8. INTRO 163 165 GH protein_type With respect to xylan degradation, the backbone of simple xylans is hydrolyzed by endo-acting xylanases, the majority of which are located in glycoside hydrolase (GH)5 families GH10 and GH11, although they are also present in GH8. INTRO 166 167 5 protein_type With respect to xylan degradation, the backbone of simple xylans is hydrolyzed by endo-acting xylanases, the majority of which are located in glycoside hydrolase (GH)5 families GH10 and GH11, although they are also present in GH8. INTRO 177 181 GH10 protein_type With respect to xylan degradation, the backbone of simple xylans is hydrolyzed by endo-acting xylanases, the majority of which are located in glycoside hydrolase (GH)5 families GH10 and GH11, although they are also present in GH8. INTRO 186 190 GH11 protein_type With respect to xylan degradation, the backbone of simple xylans is hydrolyzed by endo-acting xylanases, the majority of which are located in glycoside hydrolase (GH)5 families GH10 and GH11, although they are also present in GH8. INTRO 226 229 GH8 protein_type With respect to xylan degradation, the backbone of simple xylans is hydrolyzed by endo-acting xylanases, the majority of which are located in glycoside hydrolase (GH)5 families GH10 and GH11, although they are also present in GH8. INTRO 32 37 xylan chemical The extensive decoration of the xylan backbone generally restricts the capacity of these enzymes to attack the polysaccharide prior to removal of the side chains by a range of α-glucuronidases, α-arabinofuranosidases, and esterases. INTRO 111 125 polysaccharide chemical The extensive decoration of the xylan backbone generally restricts the capacity of these enzymes to attack the polysaccharide prior to removal of the side chains by a range of α-glucuronidases, α-arabinofuranosidases, and esterases. INTRO 176 192 α-glucuronidases protein_type The extensive decoration of the xylan backbone generally restricts the capacity of these enzymes to attack the polysaccharide prior to removal of the side chains by a range of α-glucuronidases, α-arabinofuranosidases, and esterases. INTRO 194 216 α-arabinofuranosidases protein_type The extensive decoration of the xylan backbone generally restricts the capacity of these enzymes to attack the polysaccharide prior to removal of the side chains by a range of α-glucuronidases, α-arabinofuranosidases, and esterases. INTRO 222 231 esterases protein_type The extensive decoration of the xylan backbone generally restricts the capacity of these enzymes to attack the polysaccharide prior to removal of the side chains by a range of α-glucuronidases, α-arabinofuranosidases, and esterases. INTRO 4 13 xylanases protein_type Two xylanases, however, utilize the side chains as essential specificity determinants and thus target decorated forms of the hemicellulose. INTRO 125 138 hemicellulose chemical Two xylanases, however, utilize the side chains as essential specificity determinants and thus target decorated forms of the hemicellulose. INTRO 4 8 GH30 protein_type The GH30 glucuronoxylanases require the Xylp bound at the −2 to contain a GlcA side chain (the scissile bond targeted by glycoside hydrolases is between subsites −1 and +1, and subsites that extend toward the non-reducing and reducing ends of the substrate are assigned increasing negative and positive numbers, respectively). INTRO 9 27 glucuronoxylanases protein_type The GH30 glucuronoxylanases require the Xylp bound at the −2 to contain a GlcA side chain (the scissile bond targeted by glycoside hydrolases is between subsites −1 and +1, and subsites that extend toward the non-reducing and reducing ends of the substrate are assigned increasing negative and positive numbers, respectively). INTRO 40 44 Xylp chemical The GH30 glucuronoxylanases require the Xylp bound at the −2 to contain a GlcA side chain (the scissile bond targeted by glycoside hydrolases is between subsites −1 and +1, and subsites that extend toward the non-reducing and reducing ends of the substrate are assigned increasing negative and positive numbers, respectively). INTRO 45 53 bound at protein_state The GH30 glucuronoxylanases require the Xylp bound at the −2 to contain a GlcA side chain (the scissile bond targeted by glycoside hydrolases is between subsites −1 and +1, and subsites that extend toward the non-reducing and reducing ends of the substrate are assigned increasing negative and positive numbers, respectively). INTRO 58 60 −2 site The GH30 glucuronoxylanases require the Xylp bound at the −2 to contain a GlcA side chain (the scissile bond targeted by glycoside hydrolases is between subsites −1 and +1, and subsites that extend toward the non-reducing and reducing ends of the substrate are assigned increasing negative and positive numbers, respectively). INTRO 74 78 GlcA chemical The GH30 glucuronoxylanases require the Xylp bound at the −2 to contain a GlcA side chain (the scissile bond targeted by glycoside hydrolases is between subsites −1 and +1, and subsites that extend toward the non-reducing and reducing ends of the substrate are assigned increasing negative and positive numbers, respectively). INTRO 121 141 glycoside hydrolases protein_type The GH30 glucuronoxylanases require the Xylp bound at the −2 to contain a GlcA side chain (the scissile bond targeted by glycoside hydrolases is between subsites −1 and +1, and subsites that extend toward the non-reducing and reducing ends of the substrate are assigned increasing negative and positive numbers, respectively). INTRO 153 171 subsites −1 and +1 site The GH30 glucuronoxylanases require the Xylp bound at the −2 to contain a GlcA side chain (the scissile bond targeted by glycoside hydrolases is between subsites −1 and +1, and subsites that extend toward the non-reducing and reducing ends of the substrate are assigned increasing negative and positive numbers, respectively). INTRO 177 185 subsites site The GH30 glucuronoxylanases require the Xylp bound at the −2 to contain a GlcA side chain (the scissile bond targeted by glycoside hydrolases is between subsites −1 and +1, and subsites that extend toward the non-reducing and reducing ends of the substrate are assigned increasing negative and positive numbers, respectively). INTRO 4 7 GH5 protein_type The GH5 arabinoxylanase (CtXyl5A) derived from Clostridium thermocellum displays an absolute requirement for xylans that contain Araf side chains. INTRO 8 23 arabinoxylanase protein_type The GH5 arabinoxylanase (CtXyl5A) derived from Clostridium thermocellum displays an absolute requirement for xylans that contain Araf side chains. INTRO 25 32 CtXyl5A protein The GH5 arabinoxylanase (CtXyl5A) derived from Clostridium thermocellum displays an absolute requirement for xylans that contain Araf side chains. INTRO 47 71 Clostridium thermocellum species The GH5 arabinoxylanase (CtXyl5A) derived from Clostridium thermocellum displays an absolute requirement for xylans that contain Araf side chains. INTRO 109 115 xylans chemical The GH5 arabinoxylanase (CtXyl5A) derived from Clostridium thermocellum displays an absolute requirement for xylans that contain Araf side chains. INTRO 129 133 Araf chemical The GH5 arabinoxylanase (CtXyl5A) derived from Clostridium thermocellum displays an absolute requirement for xylans that contain Araf side chains. INTRO 55 59 Araf chemical In this enzyme, the key specificity determinant is the Araf appended to O3 of the Xylp bound in the active site (−1 subsite). INTRO 82 86 Xylp chemical In this enzyme, the key specificity determinant is the Araf appended to O3 of the Xylp bound in the active site (−1 subsite). INTRO 87 95 bound in protein_state In this enzyme, the key specificity determinant is the Araf appended to O3 of the Xylp bound in the active site (−1 subsite). INTRO 100 111 active site site In this enzyme, the key specificity determinant is the Araf appended to O3 of the Xylp bound in the active site (−1 subsite). INTRO 113 123 −1 subsite site In this enzyme, the key specificity determinant is the Araf appended to O3 of the Xylp bound in the active site (−1 subsite). INTRO 37 50 arabinoxylans chemical The reaction products generated from arabinoxylans, however, suggest that Araf can be accommodated at subsites distal to the active site. INTRO 74 78 Araf chemical The reaction products generated from arabinoxylans, however, suggest that Araf can be accommodated at subsites distal to the active site. INTRO 102 110 subsites site The reaction products generated from arabinoxylans, however, suggest that Araf can be accommodated at subsites distal to the active site. INTRO 125 136 active site site The reaction products generated from arabinoxylans, however, suggest that Araf can be accommodated at subsites distal to the active site. INTRO 0 7 CtXyl5A protein CtXyl5A is a multimodular enzyme containing, in addition to the GH5 catalytic module (CtGH5); three non-catalytic carbohydrate binding modules (CBMs) belonging to families 6 (CtCBM6), 13 (CtCBM13), and 62 (CtCBM62); fibronectin type 3 (Fn3) domain; and a C-terminal dockerin domain Fig. 1. INTRO 64 67 GH5 protein_type CtXyl5A is a multimodular enzyme containing, in addition to the GH5 catalytic module (CtGH5); three non-catalytic carbohydrate binding modules (CBMs) belonging to families 6 (CtCBM6), 13 (CtCBM13), and 62 (CtCBM62); fibronectin type 3 (Fn3) domain; and a C-terminal dockerin domain Fig. 1. INTRO 68 84 catalytic module structure_element CtXyl5A is a multimodular enzyme containing, in addition to the GH5 catalytic module (CtGH5); three non-catalytic carbohydrate binding modules (CBMs) belonging to families 6 (CtCBM6), 13 (CtCBM13), and 62 (CtCBM62); fibronectin type 3 (Fn3) domain; and a C-terminal dockerin domain Fig. 1. INTRO 86 91 CtGH5 structure_element CtXyl5A is a multimodular enzyme containing, in addition to the GH5 catalytic module (CtGH5); three non-catalytic carbohydrate binding modules (CBMs) belonging to families 6 (CtCBM6), 13 (CtCBM13), and 62 (CtCBM62); fibronectin type 3 (Fn3) domain; and a C-terminal dockerin domain Fig. 1. INTRO 100 142 non-catalytic carbohydrate binding modules structure_element CtXyl5A is a multimodular enzyme containing, in addition to the GH5 catalytic module (CtGH5); three non-catalytic carbohydrate binding modules (CBMs) belonging to families 6 (CtCBM6), 13 (CtCBM13), and 62 (CtCBM62); fibronectin type 3 (Fn3) domain; and a C-terminal dockerin domain Fig. 1. INTRO 144 148 CBMs structure_element CtXyl5A is a multimodular enzyme containing, in addition to the GH5 catalytic module (CtGH5); three non-catalytic carbohydrate binding modules (CBMs) belonging to families 6 (CtCBM6), 13 (CtCBM13), and 62 (CtCBM62); fibronectin type 3 (Fn3) domain; and a C-terminal dockerin domain Fig. 1. INTRO 172 173 6 protein_type CtXyl5A is a multimodular enzyme containing, in addition to the GH5 catalytic module (CtGH5); three non-catalytic carbohydrate binding modules (CBMs) belonging to families 6 (CtCBM6), 13 (CtCBM13), and 62 (CtCBM62); fibronectin type 3 (Fn3) domain; and a C-terminal dockerin domain Fig. 1. INTRO 175 181 CtCBM6 structure_element CtXyl5A is a multimodular enzyme containing, in addition to the GH5 catalytic module (CtGH5); three non-catalytic carbohydrate binding modules (CBMs) belonging to families 6 (CtCBM6), 13 (CtCBM13), and 62 (CtCBM62); fibronectin type 3 (Fn3) domain; and a C-terminal dockerin domain Fig. 1. INTRO 184 186 13 protein_type CtXyl5A is a multimodular enzyme containing, in addition to the GH5 catalytic module (CtGH5); three non-catalytic carbohydrate binding modules (CBMs) belonging to families 6 (CtCBM6), 13 (CtCBM13), and 62 (CtCBM62); fibronectin type 3 (Fn3) domain; and a C-terminal dockerin domain Fig. 1. INTRO 188 195 CtCBM13 structure_element CtXyl5A is a multimodular enzyme containing, in addition to the GH5 catalytic module (CtGH5); three non-catalytic carbohydrate binding modules (CBMs) belonging to families 6 (CtCBM6), 13 (CtCBM13), and 62 (CtCBM62); fibronectin type 3 (Fn3) domain; and a C-terminal dockerin domain Fig. 1. INTRO 202 204 62 protein_type CtXyl5A is a multimodular enzyme containing, in addition to the GH5 catalytic module (CtGH5); three non-catalytic carbohydrate binding modules (CBMs) belonging to families 6 (CtCBM6), 13 (CtCBM13), and 62 (CtCBM62); fibronectin type 3 (Fn3) domain; and a C-terminal dockerin domain Fig. 1. INTRO 206 213 CtCBM62 structure_element CtXyl5A is a multimodular enzyme containing, in addition to the GH5 catalytic module (CtGH5); three non-catalytic carbohydrate binding modules (CBMs) belonging to families 6 (CtCBM6), 13 (CtCBM13), and 62 (CtCBM62); fibronectin type 3 (Fn3) domain; and a C-terminal dockerin domain Fig. 1. INTRO 216 234 fibronectin type 3 protein_type CtXyl5A is a multimodular enzyme containing, in addition to the GH5 catalytic module (CtGH5); three non-catalytic carbohydrate binding modules (CBMs) belonging to families 6 (CtCBM6), 13 (CtCBM13), and 62 (CtCBM62); fibronectin type 3 (Fn3) domain; and a C-terminal dockerin domain Fig. 1. INTRO 236 239 Fn3 structure_element CtXyl5A is a multimodular enzyme containing, in addition to the GH5 catalytic module (CtGH5); three non-catalytic carbohydrate binding modules (CBMs) belonging to families 6 (CtCBM6), 13 (CtCBM13), and 62 (CtCBM62); fibronectin type 3 (Fn3) domain; and a C-terminal dockerin domain Fig. 1. INTRO 266 274 dockerin structure_element CtXyl5A is a multimodular enzyme containing, in addition to the GH5 catalytic module (CtGH5); three non-catalytic carbohydrate binding modules (CBMs) belonging to families 6 (CtCBM6), 13 (CtCBM13), and 62 (CtCBM62); fibronectin type 3 (Fn3) domain; and a C-terminal dockerin domain Fig. 1. INTRO 20 23 Fn3 structure_element Previous studies of Fn3 domains have indicated that they might function as ligand-binding modules, as a compact form of peptide linkers or spacers between other domains, as cellulose-disrupting modules, or as proteins that help large enzyme complexes remain soluble. INTRO 75 97 ligand-binding modules structure_element Previous studies of Fn3 domains have indicated that they might function as ligand-binding modules, as a compact form of peptide linkers or spacers between other domains, as cellulose-disrupting modules, or as proteins that help large enzyme complexes remain soluble. INTRO 173 201 cellulose-disrupting modules structure_element Previous studies of Fn3 domains have indicated that they might function as ligand-binding modules, as a compact form of peptide linkers or spacers between other domains, as cellulose-disrupting modules, or as proteins that help large enzyme complexes remain soluble. INTRO 4 12 dockerin structure_element The dockerin domain recruits the enzyme into the cellulosome, a multienzyme plant cell wall degrading complex presented on the surface of C. thermocellum. INTRO 49 60 cellulosome complex_assembly The dockerin domain recruits the enzyme into the cellulosome, a multienzyme plant cell wall degrading complex presented on the surface of C. thermocellum. INTRO 76 81 plant taxonomy_domain The dockerin domain recruits the enzyme into the cellulosome, a multienzyme plant cell wall degrading complex presented on the surface of C. thermocellum. INTRO 138 153 C. thermocellum species The dockerin domain recruits the enzyme into the cellulosome, a multienzyme plant cell wall degrading complex presented on the surface of C. thermocellum. INTRO 0 6 CtCBM6 structure_element CtCBM6 stabilizes CtGH5, and CtCBM62 binds to d-galactopyranose and l-arabinopyranose. INTRO 18 23 CtGH5 structure_element CtCBM6 stabilizes CtGH5, and CtCBM62 binds to d-galactopyranose and l-arabinopyranose. INTRO 29 36 CtCBM62 structure_element CtCBM6 stabilizes CtGH5, and CtCBM62 binds to d-galactopyranose and l-arabinopyranose. INTRO 46 63 d-galactopyranose chemical CtCBM6 stabilizes CtGH5, and CtCBM62 binds to d-galactopyranose and l-arabinopyranose. INTRO 68 85 l-arabinopyranose chemical CtCBM6 stabilizes CtGH5, and CtCBM62 binds to d-galactopyranose and l-arabinopyranose. INTRO 20 27 CtCBM13 structure_element The function of the CtCBM13 and Fn3 modules remains unclear. INTRO 32 35 Fn3 structure_element The function of the CtCBM13 and Fn3 modules remains unclear. INTRO 25 42 crystal structure evidence This report exploits the crystal structure of mature CtXyl5A lacking its C-terminal dockerin domain (CtXyl5A-Doc), and the enzyme in complex with ligands, to explore the mechanism of substrate specificity. INTRO 46 52 mature protein_state This report exploits the crystal structure of mature CtXyl5A lacking its C-terminal dockerin domain (CtXyl5A-Doc), and the enzyme in complex with ligands, to explore the mechanism of substrate specificity. INTRO 53 60 CtXyl5A protein This report exploits the crystal structure of mature CtXyl5A lacking its C-terminal dockerin domain (CtXyl5A-Doc), and the enzyme in complex with ligands, to explore the mechanism of substrate specificity. INTRO 61 68 lacking protein_state This report exploits the crystal structure of mature CtXyl5A lacking its C-terminal dockerin domain (CtXyl5A-Doc), and the enzyme in complex with ligands, to explore the mechanism of substrate specificity. INTRO 84 92 dockerin structure_element This report exploits the crystal structure of mature CtXyl5A lacking its C-terminal dockerin domain (CtXyl5A-Doc), and the enzyme in complex with ligands, to explore the mechanism of substrate specificity. INTRO 101 112 CtXyl5A-Doc mutant This report exploits the crystal structure of mature CtXyl5A lacking its C-terminal dockerin domain (CtXyl5A-Doc), and the enzyme in complex with ligands, to explore the mechanism of substrate specificity. INTRO 130 145 in complex with protein_state This report exploits the crystal structure of mature CtXyl5A lacking its C-terminal dockerin domain (CtXyl5A-Doc), and the enzyme in complex with ligands, to explore the mechanism of substrate specificity. INTRO 146 153 ligands chemical This report exploits the crystal structure of mature CtXyl5A lacking its C-terminal dockerin domain (CtXyl5A-Doc), and the enzyme in complex with ligands, to explore the mechanism of substrate specificity. INTRO 106 112 xylans chemical The data show that the plasticity in substrate recognition enables the enzyme to hydrolyze highly complex xylans that are not accessible to classical GH10 and GH11 endo-xylanases. INTRO 150 154 GH10 protein_type The data show that the plasticity in substrate recognition enables the enzyme to hydrolyze highly complex xylans that are not accessible to classical GH10 and GH11 endo-xylanases. INTRO 159 163 GH11 protein_type The data show that the plasticity in substrate recognition enables the enzyme to hydrolyze highly complex xylans that are not accessible to classical GH10 and GH11 endo-xylanases. INTRO 164 178 endo-xylanases protein_type The data show that the plasticity in substrate recognition enables the enzyme to hydrolyze highly complex xylans that are not accessible to classical GH10 and GH11 endo-xylanases. INTRO 26 32 GH5_34 protein_type Molecular architecture of GH5_34 enzymes. FIG 20 22 GH structure_element Modules prefaced by GH, CBM, or CE are modules in the indicated glycoside hydrolase, carbohydrate binding module, or carbohydrate esterase families, respectively. FIG 24 27 CBM structure_element Modules prefaced by GH, CBM, or CE are modules in the indicated glycoside hydrolase, carbohydrate binding module, or carbohydrate esterase families, respectively. FIG 32 34 CE structure_element Modules prefaced by GH, CBM, or CE are modules in the indicated glycoside hydrolase, carbohydrate binding module, or carbohydrate esterase families, respectively. FIG 64 83 glycoside hydrolase protein_type Modules prefaced by GH, CBM, or CE are modules in the indicated glycoside hydrolase, carbohydrate binding module, or carbohydrate esterase families, respectively. FIG 85 112 carbohydrate binding module structure_element Modules prefaced by GH, CBM, or CE are modules in the indicated glycoside hydrolase, carbohydrate binding module, or carbohydrate esterase families, respectively. FIG 117 138 carbohydrate esterase protein_type Modules prefaced by GH, CBM, or CE are modules in the indicated glycoside hydrolase, carbohydrate binding module, or carbohydrate esterase families, respectively. FIG 0 11 Laminin_3_G structure_element Laminin_3_G domain belongs to the concanavalin A lectin superfamily, and FN3 denotes a fibronectin type 3 domain. FIG 34 67 concanavalin A lectin superfamily protein_type Laminin_3_G domain belongs to the concanavalin A lectin superfamily, and FN3 denotes a fibronectin type 3 domain. FIG 73 76 FN3 structure_element Laminin_3_G domain belongs to the concanavalin A lectin superfamily, and FN3 denotes a fibronectin type 3 domain. FIG 87 112 fibronectin type 3 domain structure_element Laminin_3_G domain belongs to the concanavalin A lectin superfamily, and FN3 denotes a fibronectin type 3 domain. FIG 23 31 dockerin structure_element Segments labeled D are dockerin domains. FIG 25 32 CtXyl5A protein Substrate Specificity of CtXyl5A RESULTS 29 36 CtXyl5A protein Previous studies showed that CtXyl5A is an arabinoxylan-specific xylanase that generates xylooligosaccharides with an arabinose linked O3 to the reducing end xylose. RESULTS 43 73 arabinoxylan-specific xylanase protein_type Previous studies showed that CtXyl5A is an arabinoxylan-specific xylanase that generates xylooligosaccharides with an arabinose linked O3 to the reducing end xylose. RESULTS 89 109 xylooligosaccharides chemical Previous studies showed that CtXyl5A is an arabinoxylan-specific xylanase that generates xylooligosaccharides with an arabinose linked O3 to the reducing end xylose. RESULTS 118 127 arabinose chemical Previous studies showed that CtXyl5A is an arabinoxylan-specific xylanase that generates xylooligosaccharides with an arabinose linked O3 to the reducing end xylose. RESULTS 158 164 xylose chemical Previous studies showed that CtXyl5A is an arabinoxylan-specific xylanase that generates xylooligosaccharides with an arabinose linked O3 to the reducing end xylose. RESULTS 34 39 wheat taxonomy_domain The enzyme is active against both wheat and rye arabinoxylans (abbreviated as WAX and RAX, respectively). RESULTS 44 47 rye taxonomy_domain The enzyme is active against both wheat and rye arabinoxylans (abbreviated as WAX and RAX, respectively). RESULTS 48 61 arabinoxylans chemical The enzyme is active against both wheat and rye arabinoxylans (abbreviated as WAX and RAX, respectively). RESULTS 78 81 WAX chemical The enzyme is active against both wheat and rye arabinoxylans (abbreviated as WAX and RAX, respectively). RESULTS 86 89 RAX chemical The enzyme is active against both wheat and rye arabinoxylans (abbreviated as WAX and RAX, respectively). RESULTS 21 30 arabinose chemical It was proposed that arabinose decorations make productive interactions with a pocket (−2*) that is abutted onto the active site or −1 subsite. RESULTS 79 85 pocket site It was proposed that arabinose decorations make productive interactions with a pocket (−2*) that is abutted onto the active site or −1 subsite. RESULTS 87 90 −2* site It was proposed that arabinose decorations make productive interactions with a pocket (−2*) that is abutted onto the active site or −1 subsite. RESULTS 117 128 active site site It was proposed that arabinose decorations make productive interactions with a pocket (−2*) that is abutted onto the active site or −1 subsite. RESULTS 132 142 −1 subsite site It was proposed that arabinose decorations make productive interactions with a pocket (−2*) that is abutted onto the active site or −1 subsite. RESULTS 0 9 Arabinose chemical Arabinose side chains of the other backbone xylose units in the oligosaccharides generated by CtXyl5A were essentially random. RESULTS 44 50 xylose chemical Arabinose side chains of the other backbone xylose units in the oligosaccharides generated by CtXyl5A were essentially random. RESULTS 64 80 oligosaccharides chemical Arabinose side chains of the other backbone xylose units in the oligosaccharides generated by CtXyl5A were essentially random. RESULTS 94 101 CtXyl5A protein Arabinose side chains of the other backbone xylose units in the oligosaccharides generated by CtXyl5A were essentially random. RESULTS 52 58 xylose chemical These data suggest that O3, and possibly O2, on the xylose residues at subsites distal to the active site and −2* pocket are solvent-exposed, implying that the enzyme can access highly decorated xylans. RESULTS 71 79 subsites site These data suggest that O3, and possibly O2, on the xylose residues at subsites distal to the active site and −2* pocket are solvent-exposed, implying that the enzyme can access highly decorated xylans. RESULTS 94 105 active site site These data suggest that O3, and possibly O2, on the xylose residues at subsites distal to the active site and −2* pocket are solvent-exposed, implying that the enzyme can access highly decorated xylans. RESULTS 110 120 −2* pocket site These data suggest that O3, and possibly O2, on the xylose residues at subsites distal to the active site and −2* pocket are solvent-exposed, implying that the enzyme can access highly decorated xylans. RESULTS 125 140 solvent-exposed protein_state These data suggest that O3, and possibly O2, on the xylose residues at subsites distal to the active site and −2* pocket are solvent-exposed, implying that the enzyme can access highly decorated xylans. RESULTS 195 201 xylans chemical These data suggest that O3, and possibly O2, on the xylose residues at subsites distal to the active site and −2* pocket are solvent-exposed, implying that the enzyme can access highly decorated xylans. RESULTS 41 48 CtXyl5A protein To test this hypothesis, the activity of CtXyl5A against xylans from cereal brans was assessed. RESULTS 57 63 xylans chemical To test this hypothesis, the activity of CtXyl5A against xylans from cereal brans was assessed. RESULTS 69 75 cereal taxonomy_domain To test this hypothesis, the activity of CtXyl5A against xylans from cereal brans was assessed. RESULTS 0 7 CtXyl5a protein CtXyl5a was incubated with a range of xylans for 16 h at 60 °C, and the limit products were visualized by TLC. RESULTS 12 21 incubated experimental_method CtXyl5a was incubated with a range of xylans for 16 h at 60 °C, and the limit products were visualized by TLC. RESULTS 38 44 xylans chemical CtXyl5a was incubated with a range of xylans for 16 h at 60 °C, and the limit products were visualized by TLC. RESULTS 106 109 TLC experimental_method CtXyl5a was incubated with a range of xylans for 16 h at 60 °C, and the limit products were visualized by TLC. RESULTS 6 12 xylans chemical These xylans are highly decorated not only with Araf and GlcA units but also with l-Gal, d-Gal, and d-Xyl. RESULTS 48 52 Araf chemical These xylans are highly decorated not only with Araf and GlcA units but also with l-Gal, d-Gal, and d-Xyl. RESULTS 57 61 GlcA chemical These xylans are highly decorated not only with Araf and GlcA units but also with l-Gal, d-Gal, and d-Xyl. RESULTS 82 87 l-Gal chemical These xylans are highly decorated not only with Araf and GlcA units but also with l-Gal, d-Gal, and d-Xyl. RESULTS 89 94 d-Gal chemical These xylans are highly decorated not only with Araf and GlcA units but also with l-Gal, d-Gal, and d-Xyl. RESULTS 100 105 d-Xyl chemical These xylans are highly decorated not only with Araf and GlcA units but also with l-Gal, d-Gal, and d-Xyl. RESULTS 17 23 xylose chemical Indeed, very few xylose units in the backbone of bran xylans lack side chains. RESULTS 54 60 xylans chemical Indeed, very few xylose units in the backbone of bran xylans lack side chains. RESULTS 42 49 CtXyl5A protein The data presented in Table 1 showed that CtXyl5A was active against corn bran xylan (CX). RESULTS 69 73 corn taxonomy_domain The data presented in Table 1 showed that CtXyl5A was active against corn bran xylan (CX). RESULTS 79 84 xylan chemical The data presented in Table 1 showed that CtXyl5A was active against corn bran xylan (CX). RESULTS 86 88 CX chemical The data presented in Table 1 showed that CtXyl5A was active against corn bran xylan (CX). RESULTS 20 34 endo-xylanases protein_type In contrast typical endo-xylanases from GH10 and GH11 were unable to attack CX, reflecting the lack of undecorated xylose units in the backbone (the active site of these enzymes can only bind to non-substituted xylose residues). RESULTS 40 44 GH10 protein_type In contrast typical endo-xylanases from GH10 and GH11 were unable to attack CX, reflecting the lack of undecorated xylose units in the backbone (the active site of these enzymes can only bind to non-substituted xylose residues). RESULTS 49 53 GH11 protein_type In contrast typical endo-xylanases from GH10 and GH11 were unable to attack CX, reflecting the lack of undecorated xylose units in the backbone (the active site of these enzymes can only bind to non-substituted xylose residues). RESULTS 76 78 CX chemical In contrast typical endo-xylanases from GH10 and GH11 were unable to attack CX, reflecting the lack of undecorated xylose units in the backbone (the active site of these enzymes can only bind to non-substituted xylose residues). RESULTS 95 102 lack of protein_state In contrast typical endo-xylanases from GH10 and GH11 were unable to attack CX, reflecting the lack of undecorated xylose units in the backbone (the active site of these enzymes can only bind to non-substituted xylose residues). RESULTS 115 121 xylose chemical In contrast typical endo-xylanases from GH10 and GH11 were unable to attack CX, reflecting the lack of undecorated xylose units in the backbone (the active site of these enzymes can only bind to non-substituted xylose residues). RESULTS 149 160 active site site In contrast typical endo-xylanases from GH10 and GH11 were unable to attack CX, reflecting the lack of undecorated xylose units in the backbone (the active site of these enzymes can only bind to non-substituted xylose residues). RESULTS 187 194 bind to protein_state In contrast typical endo-xylanases from GH10 and GH11 were unable to attack CX, reflecting the lack of undecorated xylose units in the backbone (the active site of these enzymes can only bind to non-substituted xylose residues). RESULTS 211 217 xylose chemical In contrast typical endo-xylanases from GH10 and GH11 were unable to attack CX, reflecting the lack of undecorated xylose units in the backbone (the active site of these enzymes can only bind to non-substituted xylose residues). RESULTS 32 39 CtXyl5A protein The limit products generated by CtXyl5A from CX consisted of an extensive range of oligosaccharides. RESULTS 45 47 CX chemical The limit products generated by CtXyl5A from CX consisted of an extensive range of oligosaccharides. RESULTS 83 99 oligosaccharides chemical The limit products generated by CtXyl5A from CX consisted of an extensive range of oligosaccharides. RESULTS 36 44 subsites site These data support the view that in subsites out with the active site the O2 and O3 groups of the bound xylose units are solvent-exposed and will thus tolerate decoration. RESULTS 58 69 active site site These data support the view that in subsites out with the active site the O2 and O3 groups of the bound xylose units are solvent-exposed and will thus tolerate decoration. RESULTS 104 110 xylose chemical These data support the view that in subsites out with the active site the O2 and O3 groups of the bound xylose units are solvent-exposed and will thus tolerate decoration. RESULTS 121 136 solvent-exposed protein_state These data support the view that in subsites out with the active site the O2 and O3 groups of the bound xylose units are solvent-exposed and will thus tolerate decoration. RESULTS 0 8 Kinetics evidence Kinetics of GH5_34 arabinoxylanases TABLE 12 18 GH5_34 protein_type Kinetics of GH5_34 arabinoxylanases TABLE 19 35 arabinoxylanases protein_type Kinetics of GH5_34 arabinoxylanases TABLE 15 19 kcat evidence "Enzyme Variant kcat/Km WAX RAX CX min−1mg−1ml CtXyl5A CtGH5-CBM6-CBM13-Fn3-CBM62 800 ND 460 CtXyl5A CtGH5-CBM6-CBM13-Fn3 1,232 ND 659 CtXyl5A CtGH5-CBM6-CBM13 1,307 ND 620 CtXyl5A CtGH5-CBM6 488 ND 102 CtXyl5A CtGH5-CBM6: E68A NA NA NA CtXyl5A CtGH5-CBM6: Y92A NA NA NA CtXyl5A CtGH5-CBM6: N135A 260 ND ND CtXyl5A CtGH5-CBM6: N139A NA NA NA AcGH5 Wild type 628 1,641 289 GpGH5 Wild type 2,600 9,986 314 VbGH5 Wild type ND ND ND VbGH5 D45A 102 203 23 " TABLE 20 22 Km evidence "Enzyme Variant kcat/Km WAX RAX CX min−1mg−1ml CtXyl5A CtGH5-CBM6-CBM13-Fn3-CBM62 800 ND 460 CtXyl5A CtGH5-CBM6-CBM13-Fn3 1,232 ND 659 CtXyl5A CtGH5-CBM6-CBM13 1,307 ND 620 CtXyl5A CtGH5-CBM6 488 ND 102 CtXyl5A CtGH5-CBM6: E68A NA NA NA CtXyl5A CtGH5-CBM6: Y92A NA NA NA CtXyl5A CtGH5-CBM6: N135A 260 ND ND CtXyl5A CtGH5-CBM6: N139A NA NA NA AcGH5 Wild type 628 1,641 289 GpGH5 Wild type 2,600 9,986 314 VbGH5 Wild type ND ND ND VbGH5 D45A 102 203 23 " TABLE 25 28 WAX chemical "Enzyme Variant kcat/Km WAX RAX CX min−1mg−1ml CtXyl5A CtGH5-CBM6-CBM13-Fn3-CBM62 800 ND 460 CtXyl5A CtGH5-CBM6-CBM13-Fn3 1,232 ND 659 CtXyl5A CtGH5-CBM6-CBM13 1,307 ND 620 CtXyl5A CtGH5-CBM6 488 ND 102 CtXyl5A CtGH5-CBM6: E68A NA NA NA CtXyl5A CtGH5-CBM6: Y92A NA NA NA CtXyl5A CtGH5-CBM6: N135A 260 ND ND CtXyl5A CtGH5-CBM6: N139A NA NA NA AcGH5 Wild type 628 1,641 289 GpGH5 Wild type 2,600 9,986 314 VbGH5 Wild type ND ND ND VbGH5 D45A 102 203 23 " TABLE 29 32 RAX chemical "Enzyme Variant kcat/Km WAX RAX CX min−1mg−1ml CtXyl5A CtGH5-CBM6-CBM13-Fn3-CBM62 800 ND 460 CtXyl5A CtGH5-CBM6-CBM13-Fn3 1,232 ND 659 CtXyl5A CtGH5-CBM6-CBM13 1,307 ND 620 CtXyl5A CtGH5-CBM6 488 ND 102 CtXyl5A CtGH5-CBM6: E68A NA NA NA CtXyl5A CtGH5-CBM6: Y92A NA NA NA CtXyl5A CtGH5-CBM6: N135A 260 ND ND CtXyl5A CtGH5-CBM6: N139A NA NA NA AcGH5 Wild type 628 1,641 289 GpGH5 Wild type 2,600 9,986 314 VbGH5 Wild type ND ND ND VbGH5 D45A 102 203 23 " TABLE 33 35 CX chemical "Enzyme Variant kcat/Km WAX RAX CX min−1mg−1ml CtXyl5A CtGH5-CBM6-CBM13-Fn3-CBM62 800 ND 460 CtXyl5A CtGH5-CBM6-CBM13-Fn3 1,232 ND 659 CtXyl5A CtGH5-CBM6-CBM13 1,307 ND 620 CtXyl5A CtGH5-CBM6 488 ND 102 CtXyl5A CtGH5-CBM6: E68A NA NA NA CtXyl5A CtGH5-CBM6: Y92A NA NA NA CtXyl5A CtGH5-CBM6: N135A 260 ND ND CtXyl5A CtGH5-CBM6: N139A NA NA NA AcGH5 Wild type 628 1,641 289 GpGH5 Wild type 2,600 9,986 314 VbGH5 Wild type ND ND ND VbGH5 D45A 102 203 23 " TABLE 54 61 CtXyl5A protein "Enzyme Variant kcat/Km WAX RAX CX min−1mg−1ml CtXyl5A CtGH5-CBM6-CBM13-Fn3-CBM62 800 ND 460 CtXyl5A CtGH5-CBM6-CBM13-Fn3 1,232 ND 659 CtXyl5A CtGH5-CBM6-CBM13 1,307 ND 620 CtXyl5A CtGH5-CBM6 488 ND 102 CtXyl5A CtGH5-CBM6: E68A NA NA NA CtXyl5A CtGH5-CBM6: Y92A NA NA NA CtXyl5A CtGH5-CBM6: N135A 260 ND ND CtXyl5A CtGH5-CBM6: N139A NA NA NA AcGH5 Wild type 628 1,641 289 GpGH5 Wild type 2,600 9,986 314 VbGH5 Wild type ND ND ND VbGH5 D45A 102 203 23 " TABLE 62 88 CtGH5-CBM6-CBM13-Fn3-CBM62 structure_element "Enzyme Variant kcat/Km WAX RAX CX min−1mg−1ml CtXyl5A CtGH5-CBM6-CBM13-Fn3-CBM62 800 ND 460 CtXyl5A CtGH5-CBM6-CBM13-Fn3 1,232 ND 659 CtXyl5A CtGH5-CBM6-CBM13 1,307 ND 620 CtXyl5A CtGH5-CBM6 488 ND 102 CtXyl5A CtGH5-CBM6: E68A NA NA NA CtXyl5A CtGH5-CBM6: Y92A NA NA NA CtXyl5A CtGH5-CBM6: N135A 260 ND ND CtXyl5A CtGH5-CBM6: N139A NA NA NA AcGH5 Wild type 628 1,641 289 GpGH5 Wild type 2,600 9,986 314 VbGH5 Wild type ND ND ND VbGH5 D45A 102 203 23 " TABLE 102 109 CtXyl5A protein "Enzyme Variant kcat/Km WAX RAX CX min−1mg−1ml CtXyl5A CtGH5-CBM6-CBM13-Fn3-CBM62 800 ND 460 CtXyl5A CtGH5-CBM6-CBM13-Fn3 1,232 ND 659 CtXyl5A CtGH5-CBM6-CBM13 1,307 ND 620 CtXyl5A CtGH5-CBM6 488 ND 102 CtXyl5A CtGH5-CBM6: E68A NA NA NA CtXyl5A CtGH5-CBM6: Y92A NA NA NA CtXyl5A CtGH5-CBM6: N135A 260 ND ND CtXyl5A CtGH5-CBM6: N139A NA NA NA AcGH5 Wild type 628 1,641 289 GpGH5 Wild type 2,600 9,986 314 VbGH5 Wild type ND ND ND VbGH5 D45A 102 203 23 " TABLE 110 130 CtGH5-CBM6-CBM13-Fn3 structure_element "Enzyme Variant kcat/Km WAX RAX CX min−1mg−1ml CtXyl5A CtGH5-CBM6-CBM13-Fn3-CBM62 800 ND 460 CtXyl5A CtGH5-CBM6-CBM13-Fn3 1,232 ND 659 CtXyl5A CtGH5-CBM6-CBM13 1,307 ND 620 CtXyl5A CtGH5-CBM6 488 ND 102 CtXyl5A CtGH5-CBM6: E68A NA NA NA CtXyl5A CtGH5-CBM6: Y92A NA NA NA CtXyl5A CtGH5-CBM6: N135A 260 ND ND CtXyl5A CtGH5-CBM6: N139A NA NA NA AcGH5 Wild type 628 1,641 289 GpGH5 Wild type 2,600 9,986 314 VbGH5 Wild type ND ND ND VbGH5 D45A 102 203 23 " TABLE 146 153 CtXyl5A protein "Enzyme Variant kcat/Km WAX RAX CX min−1mg−1ml CtXyl5A CtGH5-CBM6-CBM13-Fn3-CBM62 800 ND 460 CtXyl5A CtGH5-CBM6-CBM13-Fn3 1,232 ND 659 CtXyl5A CtGH5-CBM6-CBM13 1,307 ND 620 CtXyl5A CtGH5-CBM6 488 ND 102 CtXyl5A CtGH5-CBM6: E68A NA NA NA CtXyl5A CtGH5-CBM6: Y92A NA NA NA CtXyl5A CtGH5-CBM6: N135A 260 ND ND CtXyl5A CtGH5-CBM6: N139A NA NA NA AcGH5 Wild type 628 1,641 289 GpGH5 Wild type 2,600 9,986 314 VbGH5 Wild type ND ND ND VbGH5 D45A 102 203 23 " TABLE 154 170 CtGH5-CBM6-CBM13 structure_element "Enzyme Variant kcat/Km WAX RAX CX min−1mg−1ml CtXyl5A CtGH5-CBM6-CBM13-Fn3-CBM62 800 ND 460 CtXyl5A CtGH5-CBM6-CBM13-Fn3 1,232 ND 659 CtXyl5A CtGH5-CBM6-CBM13 1,307 ND 620 CtXyl5A CtGH5-CBM6 488 ND 102 CtXyl5A CtGH5-CBM6: E68A NA NA NA CtXyl5A CtGH5-CBM6: Y92A NA NA NA CtXyl5A CtGH5-CBM6: N135A 260 ND ND CtXyl5A CtGH5-CBM6: N139A NA NA NA AcGH5 Wild type 628 1,641 289 GpGH5 Wild type 2,600 9,986 314 VbGH5 Wild type ND ND ND VbGH5 D45A 102 203 23 " TABLE 186 193 CtXyl5A protein "Enzyme Variant kcat/Km WAX RAX CX min−1mg−1ml CtXyl5A CtGH5-CBM6-CBM13-Fn3-CBM62 800 ND 460 CtXyl5A CtGH5-CBM6-CBM13-Fn3 1,232 ND 659 CtXyl5A CtGH5-CBM6-CBM13 1,307 ND 620 CtXyl5A CtGH5-CBM6 488 ND 102 CtXyl5A CtGH5-CBM6: E68A NA NA NA CtXyl5A CtGH5-CBM6: Y92A NA NA NA CtXyl5A CtGH5-CBM6: N135A 260 ND ND CtXyl5A CtGH5-CBM6: N139A NA NA NA AcGH5 Wild type 628 1,641 289 GpGH5 Wild type 2,600 9,986 314 VbGH5 Wild type ND ND ND VbGH5 D45A 102 203 23 " TABLE 194 204 CtGH5-CBM6 structure_element "Enzyme Variant kcat/Km WAX RAX CX min−1mg−1ml CtXyl5A CtGH5-CBM6-CBM13-Fn3-CBM62 800 ND 460 CtXyl5A CtGH5-CBM6-CBM13-Fn3 1,232 ND 659 CtXyl5A CtGH5-CBM6-CBM13 1,307 ND 620 CtXyl5A CtGH5-CBM6 488 ND 102 CtXyl5A CtGH5-CBM6: E68A NA NA NA CtXyl5A CtGH5-CBM6: Y92A NA NA NA CtXyl5A CtGH5-CBM6: N135A 260 ND ND CtXyl5A CtGH5-CBM6: N139A NA NA NA AcGH5 Wild type 628 1,641 289 GpGH5 Wild type 2,600 9,986 314 VbGH5 Wild type ND ND ND VbGH5 D45A 102 203 23 " TABLE 218 225 CtXyl5A protein "Enzyme Variant kcat/Km WAX RAX CX min−1mg−1ml CtXyl5A CtGH5-CBM6-CBM13-Fn3-CBM62 800 ND 460 CtXyl5A CtGH5-CBM6-CBM13-Fn3 1,232 ND 659 CtXyl5A CtGH5-CBM6-CBM13 1,307 ND 620 CtXyl5A CtGH5-CBM6 488 ND 102 CtXyl5A CtGH5-CBM6: E68A NA NA NA CtXyl5A CtGH5-CBM6: Y92A NA NA NA CtXyl5A CtGH5-CBM6: N135A 260 ND ND CtXyl5A CtGH5-CBM6: N139A NA NA NA AcGH5 Wild type 628 1,641 289 GpGH5 Wild type 2,600 9,986 314 VbGH5 Wild type ND ND ND VbGH5 D45A 102 203 23 " TABLE 226 236 CtGH5-CBM6 structure_element "Enzyme Variant kcat/Km WAX RAX CX min−1mg−1ml CtXyl5A CtGH5-CBM6-CBM13-Fn3-CBM62 800 ND 460 CtXyl5A CtGH5-CBM6-CBM13-Fn3 1,232 ND 659 CtXyl5A CtGH5-CBM6-CBM13 1,307 ND 620 CtXyl5A CtGH5-CBM6 488 ND 102 CtXyl5A CtGH5-CBM6: E68A NA NA NA CtXyl5A CtGH5-CBM6: Y92A NA NA NA CtXyl5A CtGH5-CBM6: N135A 260 ND ND CtXyl5A CtGH5-CBM6: N139A NA NA NA AcGH5 Wild type 628 1,641 289 GpGH5 Wild type 2,600 9,986 314 VbGH5 Wild type ND ND ND VbGH5 D45A 102 203 23 " TABLE 238 242 E68A mutant "Enzyme Variant kcat/Km WAX RAX CX min−1mg−1ml CtXyl5A CtGH5-CBM6-CBM13-Fn3-CBM62 800 ND 460 CtXyl5A CtGH5-CBM6-CBM13-Fn3 1,232 ND 659 CtXyl5A CtGH5-CBM6-CBM13 1,307 ND 620 CtXyl5A CtGH5-CBM6 488 ND 102 CtXyl5A CtGH5-CBM6: E68A NA NA NA CtXyl5A CtGH5-CBM6: Y92A NA NA NA CtXyl5A CtGH5-CBM6: N135A 260 ND ND CtXyl5A CtGH5-CBM6: N139A NA NA NA AcGH5 Wild type 628 1,641 289 GpGH5 Wild type 2,600 9,986 314 VbGH5 Wild type ND ND ND VbGH5 D45A 102 203 23 " TABLE 254 261 CtXyl5A protein "Enzyme Variant kcat/Km WAX RAX CX min−1mg−1ml CtXyl5A CtGH5-CBM6-CBM13-Fn3-CBM62 800 ND 460 CtXyl5A CtGH5-CBM6-CBM13-Fn3 1,232 ND 659 CtXyl5A CtGH5-CBM6-CBM13 1,307 ND 620 CtXyl5A CtGH5-CBM6 488 ND 102 CtXyl5A CtGH5-CBM6: E68A NA NA NA CtXyl5A CtGH5-CBM6: Y92A NA NA NA CtXyl5A CtGH5-CBM6: N135A 260 ND ND CtXyl5A CtGH5-CBM6: N139A NA NA NA AcGH5 Wild type 628 1,641 289 GpGH5 Wild type 2,600 9,986 314 VbGH5 Wild type ND ND ND VbGH5 D45A 102 203 23 " TABLE 262 272 CtGH5-CBM6 structure_element "Enzyme Variant kcat/Km WAX RAX CX min−1mg−1ml CtXyl5A CtGH5-CBM6-CBM13-Fn3-CBM62 800 ND 460 CtXyl5A CtGH5-CBM6-CBM13-Fn3 1,232 ND 659 CtXyl5A CtGH5-CBM6-CBM13 1,307 ND 620 CtXyl5A CtGH5-CBM6 488 ND 102 CtXyl5A CtGH5-CBM6: E68A NA NA NA CtXyl5A CtGH5-CBM6: Y92A NA NA NA CtXyl5A CtGH5-CBM6: N135A 260 ND ND CtXyl5A CtGH5-CBM6: N139A NA NA NA AcGH5 Wild type 628 1,641 289 GpGH5 Wild type 2,600 9,986 314 VbGH5 Wild type ND ND ND VbGH5 D45A 102 203 23 " TABLE 274 278 Y92A mutant "Enzyme Variant kcat/Km WAX RAX CX min−1mg−1ml CtXyl5A CtGH5-CBM6-CBM13-Fn3-CBM62 800 ND 460 CtXyl5A CtGH5-CBM6-CBM13-Fn3 1,232 ND 659 CtXyl5A CtGH5-CBM6-CBM13 1,307 ND 620 CtXyl5A CtGH5-CBM6 488 ND 102 CtXyl5A CtGH5-CBM6: E68A NA NA NA CtXyl5A CtGH5-CBM6: Y92A NA NA NA CtXyl5A CtGH5-CBM6: N135A 260 ND ND CtXyl5A CtGH5-CBM6: N139A NA NA NA AcGH5 Wild type 628 1,641 289 GpGH5 Wild type 2,600 9,986 314 VbGH5 Wild type ND ND ND VbGH5 D45A 102 203 23 " TABLE 290 297 CtXyl5A protein "Enzyme Variant kcat/Km WAX RAX CX min−1mg−1ml CtXyl5A CtGH5-CBM6-CBM13-Fn3-CBM62 800 ND 460 CtXyl5A CtGH5-CBM6-CBM13-Fn3 1,232 ND 659 CtXyl5A CtGH5-CBM6-CBM13 1,307 ND 620 CtXyl5A CtGH5-CBM6 488 ND 102 CtXyl5A CtGH5-CBM6: E68A NA NA NA CtXyl5A CtGH5-CBM6: Y92A NA NA NA CtXyl5A CtGH5-CBM6: N135A 260 ND ND CtXyl5A CtGH5-CBM6: N139A NA NA NA AcGH5 Wild type 628 1,641 289 GpGH5 Wild type 2,600 9,986 314 VbGH5 Wild type ND ND ND VbGH5 D45A 102 203 23 " TABLE 298 308 CtGH5-CBM6 structure_element "Enzyme Variant kcat/Km WAX RAX CX min−1mg−1ml CtXyl5A CtGH5-CBM6-CBM13-Fn3-CBM62 800 ND 460 CtXyl5A CtGH5-CBM6-CBM13-Fn3 1,232 ND 659 CtXyl5A CtGH5-CBM6-CBM13 1,307 ND 620 CtXyl5A CtGH5-CBM6 488 ND 102 CtXyl5A CtGH5-CBM6: E68A NA NA NA CtXyl5A CtGH5-CBM6: Y92A NA NA NA CtXyl5A CtGH5-CBM6: N135A 260 ND ND CtXyl5A CtGH5-CBM6: N139A NA NA NA AcGH5 Wild type 628 1,641 289 GpGH5 Wild type 2,600 9,986 314 VbGH5 Wild type ND ND ND VbGH5 D45A 102 203 23 " TABLE 310 315 N135A mutant "Enzyme Variant kcat/Km WAX RAX CX min−1mg−1ml CtXyl5A CtGH5-CBM6-CBM13-Fn3-CBM62 800 ND 460 CtXyl5A CtGH5-CBM6-CBM13-Fn3 1,232 ND 659 CtXyl5A CtGH5-CBM6-CBM13 1,307 ND 620 CtXyl5A CtGH5-CBM6 488 ND 102 CtXyl5A CtGH5-CBM6: E68A NA NA NA CtXyl5A CtGH5-CBM6: Y92A NA NA NA CtXyl5A CtGH5-CBM6: N135A 260 ND ND CtXyl5A CtGH5-CBM6: N139A NA NA NA AcGH5 Wild type 628 1,641 289 GpGH5 Wild type 2,600 9,986 314 VbGH5 Wild type ND ND ND VbGH5 D45A 102 203 23 " TABLE 328 335 CtXyl5A protein "Enzyme Variant kcat/Km WAX RAX CX min−1mg−1ml CtXyl5A CtGH5-CBM6-CBM13-Fn3-CBM62 800 ND 460 CtXyl5A CtGH5-CBM6-CBM13-Fn3 1,232 ND 659 CtXyl5A CtGH5-CBM6-CBM13 1,307 ND 620 CtXyl5A CtGH5-CBM6 488 ND 102 CtXyl5A CtGH5-CBM6: E68A NA NA NA CtXyl5A CtGH5-CBM6: Y92A NA NA NA CtXyl5A CtGH5-CBM6: N135A 260 ND ND CtXyl5A CtGH5-CBM6: N139A NA NA NA AcGH5 Wild type 628 1,641 289 GpGH5 Wild type 2,600 9,986 314 VbGH5 Wild type ND ND ND VbGH5 D45A 102 203 23 " TABLE 336 346 CtGH5-CBM6 structure_element "Enzyme Variant kcat/Km WAX RAX CX min−1mg−1ml CtXyl5A CtGH5-CBM6-CBM13-Fn3-CBM62 800 ND 460 CtXyl5A CtGH5-CBM6-CBM13-Fn3 1,232 ND 659 CtXyl5A CtGH5-CBM6-CBM13 1,307 ND 620 CtXyl5A CtGH5-CBM6 488 ND 102 CtXyl5A CtGH5-CBM6: E68A NA NA NA CtXyl5A CtGH5-CBM6: Y92A NA NA NA CtXyl5A CtGH5-CBM6: N135A 260 ND ND CtXyl5A CtGH5-CBM6: N139A NA NA NA AcGH5 Wild type 628 1,641 289 GpGH5 Wild type 2,600 9,986 314 VbGH5 Wild type ND ND ND VbGH5 D45A 102 203 23 " TABLE 348 353 N139A mutant "Enzyme Variant kcat/Km WAX RAX CX min−1mg−1ml CtXyl5A CtGH5-CBM6-CBM13-Fn3-CBM62 800 ND 460 CtXyl5A CtGH5-CBM6-CBM13-Fn3 1,232 ND 659 CtXyl5A CtGH5-CBM6-CBM13 1,307 ND 620 CtXyl5A CtGH5-CBM6 488 ND 102 CtXyl5A CtGH5-CBM6: E68A NA NA NA CtXyl5A CtGH5-CBM6: Y92A NA NA NA CtXyl5A CtGH5-CBM6: N135A 260 ND ND CtXyl5A CtGH5-CBM6: N139A NA NA NA AcGH5 Wild type 628 1,641 289 GpGH5 Wild type 2,600 9,986 314 VbGH5 Wild type ND ND ND VbGH5 D45A 102 203 23 " TABLE 365 370 AcGH5 protein "Enzyme Variant kcat/Km WAX RAX CX min−1mg−1ml CtXyl5A CtGH5-CBM6-CBM13-Fn3-CBM62 800 ND 460 CtXyl5A CtGH5-CBM6-CBM13-Fn3 1,232 ND 659 CtXyl5A CtGH5-CBM6-CBM13 1,307 ND 620 CtXyl5A CtGH5-CBM6 488 ND 102 CtXyl5A CtGH5-CBM6: E68A NA NA NA CtXyl5A CtGH5-CBM6: Y92A NA NA NA CtXyl5A CtGH5-CBM6: N135A 260 ND ND CtXyl5A CtGH5-CBM6: N139A NA NA NA AcGH5 Wild type 628 1,641 289 GpGH5 Wild type 2,600 9,986 314 VbGH5 Wild type ND ND ND VbGH5 D45A 102 203 23 " TABLE 371 380 Wild type protein_state "Enzyme Variant kcat/Km WAX RAX CX min−1mg−1ml CtXyl5A CtGH5-CBM6-CBM13-Fn3-CBM62 800 ND 460 CtXyl5A CtGH5-CBM6-CBM13-Fn3 1,232 ND 659 CtXyl5A CtGH5-CBM6-CBM13 1,307 ND 620 CtXyl5A CtGH5-CBM6 488 ND 102 CtXyl5A CtGH5-CBM6: E68A NA NA NA CtXyl5A CtGH5-CBM6: Y92A NA NA NA CtXyl5A CtGH5-CBM6: N135A 260 ND ND CtXyl5A CtGH5-CBM6: N139A NA NA NA AcGH5 Wild type 628 1,641 289 GpGH5 Wild type 2,600 9,986 314 VbGH5 Wild type ND ND ND VbGH5 D45A 102 203 23 " TABLE 397 402 GpGH5 protein "Enzyme Variant kcat/Km WAX RAX CX min−1mg−1ml CtXyl5A CtGH5-CBM6-CBM13-Fn3-CBM62 800 ND 460 CtXyl5A CtGH5-CBM6-CBM13-Fn3 1,232 ND 659 CtXyl5A CtGH5-CBM6-CBM13 1,307 ND 620 CtXyl5A CtGH5-CBM6 488 ND 102 CtXyl5A CtGH5-CBM6: E68A NA NA NA CtXyl5A CtGH5-CBM6: Y92A NA NA NA CtXyl5A CtGH5-CBM6: N135A 260 ND ND CtXyl5A CtGH5-CBM6: N139A NA NA NA AcGH5 Wild type 628 1,641 289 GpGH5 Wild type 2,600 9,986 314 VbGH5 Wild type ND ND ND VbGH5 D45A 102 203 23 " TABLE 403 412 Wild type protein_state "Enzyme Variant kcat/Km WAX RAX CX min−1mg−1ml CtXyl5A CtGH5-CBM6-CBM13-Fn3-CBM62 800 ND 460 CtXyl5A CtGH5-CBM6-CBM13-Fn3 1,232 ND 659 CtXyl5A CtGH5-CBM6-CBM13 1,307 ND 620 CtXyl5A CtGH5-CBM6 488 ND 102 CtXyl5A CtGH5-CBM6: E68A NA NA NA CtXyl5A CtGH5-CBM6: Y92A NA NA NA CtXyl5A CtGH5-CBM6: N135A 260 ND ND CtXyl5A CtGH5-CBM6: N139A NA NA NA AcGH5 Wild type 628 1,641 289 GpGH5 Wild type 2,600 9,986 314 VbGH5 Wild type ND ND ND VbGH5 D45A 102 203 23 " TABLE 431 436 VbGH5 protein "Enzyme Variant kcat/Km WAX RAX CX min−1mg−1ml CtXyl5A CtGH5-CBM6-CBM13-Fn3-CBM62 800 ND 460 CtXyl5A CtGH5-CBM6-CBM13-Fn3 1,232 ND 659 CtXyl5A CtGH5-CBM6-CBM13 1,307 ND 620 CtXyl5A CtGH5-CBM6 488 ND 102 CtXyl5A CtGH5-CBM6: E68A NA NA NA CtXyl5A CtGH5-CBM6: Y92A NA NA NA CtXyl5A CtGH5-CBM6: N135A 260 ND ND CtXyl5A CtGH5-CBM6: N139A NA NA NA AcGH5 Wild type 628 1,641 289 GpGH5 Wild type 2,600 9,986 314 VbGH5 Wild type ND ND ND VbGH5 D45A 102 203 23 " TABLE 437 446 Wild type protein_state "Enzyme Variant kcat/Km WAX RAX CX min−1mg−1ml CtXyl5A CtGH5-CBM6-CBM13-Fn3-CBM62 800 ND 460 CtXyl5A CtGH5-CBM6-CBM13-Fn3 1,232 ND 659 CtXyl5A CtGH5-CBM6-CBM13 1,307 ND 620 CtXyl5A CtGH5-CBM6 488 ND 102 CtXyl5A CtGH5-CBM6: E68A NA NA NA CtXyl5A CtGH5-CBM6: Y92A NA NA NA CtXyl5A CtGH5-CBM6: N135A 260 ND ND CtXyl5A CtGH5-CBM6: N139A NA NA NA AcGH5 Wild type 628 1,641 289 GpGH5 Wild type 2,600 9,986 314 VbGH5 Wild type ND ND ND VbGH5 D45A 102 203 23 " TABLE 458 463 VbGH5 protein "Enzyme Variant kcat/Km WAX RAX CX min−1mg−1ml CtXyl5A CtGH5-CBM6-CBM13-Fn3-CBM62 800 ND 460 CtXyl5A CtGH5-CBM6-CBM13-Fn3 1,232 ND 659 CtXyl5A CtGH5-CBM6-CBM13 1,307 ND 620 CtXyl5A CtGH5-CBM6 488 ND 102 CtXyl5A CtGH5-CBM6: E68A NA NA NA CtXyl5A CtGH5-CBM6: Y92A NA NA NA CtXyl5A CtGH5-CBM6: N135A 260 ND ND CtXyl5A CtGH5-CBM6: N139A NA NA NA AcGH5 Wild type 628 1,641 289 GpGH5 Wild type 2,600 9,986 314 VbGH5 Wild type ND ND ND VbGH5 D45A 102 203 23 " TABLE 464 468 D45A mutant "Enzyme Variant kcat/Km WAX RAX CX min−1mg−1ml CtXyl5A CtGH5-CBM6-CBM13-Fn3-CBM62 800 ND 460 CtXyl5A CtGH5-CBM6-CBM13-Fn3 1,232 ND 659 CtXyl5A CtGH5-CBM6-CBM13 1,307 ND 620 CtXyl5A CtGH5-CBM6 488 ND 102 CtXyl5A CtGH5-CBM6: E68A NA NA NA CtXyl5A CtGH5-CBM6: Y92A NA NA NA CtXyl5A CtGH5-CBM6: N135A 260 ND ND CtXyl5A CtGH5-CBM6: N139A NA NA NA AcGH5 Wild type 628 1,641 289 GpGH5 Wild type 2,600 9,986 314 VbGH5 Wild type ND ND ND VbGH5 D45A 102 203 23 " TABLE 29 42 bound only at protein_state To explore whether substrate bound only at −2* and −1 in the negative subsites was hydrolyzed by CtXyl5A, the limit products of CX digested by the arabinoxylanase were subjected to size exclusion chromatography using a Bio-Gel P-2, and the smallest oligosaccharides (largest elution volume) were chosen for further study. RESULTS 43 46 −2* site To explore whether substrate bound only at −2* and −1 in the negative subsites was hydrolyzed by CtXyl5A, the limit products of CX digested by the arabinoxylanase were subjected to size exclusion chromatography using a Bio-Gel P-2, and the smallest oligosaccharides (largest elution volume) were chosen for further study. RESULTS 51 53 −1 site To explore whether substrate bound only at −2* and −1 in the negative subsites was hydrolyzed by CtXyl5A, the limit products of CX digested by the arabinoxylanase were subjected to size exclusion chromatography using a Bio-Gel P-2, and the smallest oligosaccharides (largest elution volume) were chosen for further study. RESULTS 61 78 negative subsites site To explore whether substrate bound only at −2* and −1 in the negative subsites was hydrolyzed by CtXyl5A, the limit products of CX digested by the arabinoxylanase were subjected to size exclusion chromatography using a Bio-Gel P-2, and the smallest oligosaccharides (largest elution volume) were chosen for further study. RESULTS 97 104 CtXyl5A protein To explore whether substrate bound only at −2* and −1 in the negative subsites was hydrolyzed by CtXyl5A, the limit products of CX digested by the arabinoxylanase were subjected to size exclusion chromatography using a Bio-Gel P-2, and the smallest oligosaccharides (largest elution volume) were chosen for further study. RESULTS 128 130 CX chemical To explore whether substrate bound only at −2* and −1 in the negative subsites was hydrolyzed by CtXyl5A, the limit products of CX digested by the arabinoxylanase were subjected to size exclusion chromatography using a Bio-Gel P-2, and the smallest oligosaccharides (largest elution volume) were chosen for further study. RESULTS 147 162 arabinoxylanase protein_type To explore whether substrate bound only at −2* and −1 in the negative subsites was hydrolyzed by CtXyl5A, the limit products of CX digested by the arabinoxylanase were subjected to size exclusion chromatography using a Bio-Gel P-2, and the smallest oligosaccharides (largest elution volume) were chosen for further study. RESULTS 181 210 size exclusion chromatography experimental_method To explore whether substrate bound only at −2* and −1 in the negative subsites was hydrolyzed by CtXyl5A, the limit products of CX digested by the arabinoxylanase were subjected to size exclusion chromatography using a Bio-Gel P-2, and the smallest oligosaccharides (largest elution volume) were chosen for further study. RESULTS 249 265 oligosaccharides chemical To explore whether substrate bound only at −2* and −1 in the negative subsites was hydrolyzed by CtXyl5A, the limit products of CX digested by the arabinoxylanase were subjected to size exclusion chromatography using a Bio-Gel P-2, and the smallest oligosaccharides (largest elution volume) were chosen for further study. RESULTS 0 5 HPAEC experimental_method HPAEC analysis of the smallest oligosaccharide fraction (pool 4) contained two species with retention times of 14.0 min (oligosaccharide 1) and 20.8 min (oligosaccharide 2) (Fig. 2). RESULTS 31 46 oligosaccharide chemical HPAEC analysis of the smallest oligosaccharide fraction (pool 4) contained two species with retention times of 14.0 min (oligosaccharide 1) and 20.8 min (oligosaccharide 2) (Fig. 2). RESULTS 121 136 oligosaccharide chemical HPAEC analysis of the smallest oligosaccharide fraction (pool 4) contained two species with retention times of 14.0 min (oligosaccharide 1) and 20.8 min (oligosaccharide 2) (Fig. 2). RESULTS 154 169 oligosaccharide chemical HPAEC analysis of the smallest oligosaccharide fraction (pool 4) contained two species with retention times of 14.0 min (oligosaccharide 1) and 20.8 min (oligosaccharide 2) (Fig. 2). RESULTS 0 44 Positive mode electrospray mass spectrometry experimental_method Positive mode electrospray mass spectrometry showed that pool 4 contained exclusively molecular ions with a m/z = 305 [M + Na]+, which corresponds to a pentose-pentose disaccharide (molecular mass = 282 Da) as a sodium ion adduct, whereas a dimer of the disaccharide with a sodium adduct (m/z = 587 [2M+Na]+) was also evident. RESULTS 152 159 pentose chemical Positive mode electrospray mass spectrometry showed that pool 4 contained exclusively molecular ions with a m/z = 305 [M + Na]+, which corresponds to a pentose-pentose disaccharide (molecular mass = 282 Da) as a sodium ion adduct, whereas a dimer of the disaccharide with a sodium adduct (m/z = 587 [2M+Na]+) was also evident. RESULTS 160 167 pentose chemical Positive mode electrospray mass spectrometry showed that pool 4 contained exclusively molecular ions with a m/z = 305 [M + Na]+, which corresponds to a pentose-pentose disaccharide (molecular mass = 282 Da) as a sodium ion adduct, whereas a dimer of the disaccharide with a sodium adduct (m/z = 587 [2M+Na]+) was also evident. RESULTS 168 180 disaccharide chemical Positive mode electrospray mass spectrometry showed that pool 4 contained exclusively molecular ions with a m/z = 305 [M + Na]+, which corresponds to a pentose-pentose disaccharide (molecular mass = 282 Da) as a sodium ion adduct, whereas a dimer of the disaccharide with a sodium adduct (m/z = 587 [2M+Na]+) was also evident. RESULTS 254 266 disaccharide chemical Positive mode electrospray mass spectrometry showed that pool 4 contained exclusively molecular ions with a m/z = 305 [M + Na]+, which corresponds to a pentose-pentose disaccharide (molecular mass = 282 Da) as a sodium ion adduct, whereas a dimer of the disaccharide with a sodium adduct (m/z = 587 [2M+Na]+) was also evident. RESULTS 55 69 TFA hydrolysis experimental_method The monosaccharide composition of pool 4 determined by TFA hydrolysis contained xylose and arabinose in a 3:1 ratio. RESULTS 80 86 xylose chemical The monosaccharide composition of pool 4 determined by TFA hydrolysis contained xylose and arabinose in a 3:1 ratio. RESULTS 91 100 arabinose chemical The monosaccharide composition of pool 4 determined by TFA hydrolysis contained xylose and arabinose in a 3:1 ratio. RESULTS 27 43 oligosaccharides chemical This suggests that the two oligosaccharides consist of two disaccharides: one consisting of two xylose residues and the other consisting of an arabinose linked to a xylose. RESULTS 59 72 disaccharides chemical This suggests that the two oligosaccharides consist of two disaccharides: one consisting of two xylose residues and the other consisting of an arabinose linked to a xylose. RESULTS 96 102 xylose chemical This suggests that the two oligosaccharides consist of two disaccharides: one consisting of two xylose residues and the other consisting of an arabinose linked to a xylose. RESULTS 143 152 arabinose chemical This suggests that the two oligosaccharides consist of two disaccharides: one consisting of two xylose residues and the other consisting of an arabinose linked to a xylose. RESULTS 165 171 xylose chemical This suggests that the two oligosaccharides consist of two disaccharides: one consisting of two xylose residues and the other consisting of an arabinose linked to a xylose. RESULTS 29 60 nonspecific arabinofuranosidase protein_type Treatment of pool 4 with the nonspecific arabinofuranosidase, CjAbf51A, resulted in the loss of oligosaccharide 2 and the production of both xylose and arabinose, indicative of a disaccharide of xylose and arabinose. RESULTS 62 70 CjAbf51A protein Treatment of pool 4 with the nonspecific arabinofuranosidase, CjAbf51A, resulted in the loss of oligosaccharide 2 and the production of both xylose and arabinose, indicative of a disaccharide of xylose and arabinose. RESULTS 96 111 oligosaccharide chemical Treatment of pool 4 with the nonspecific arabinofuranosidase, CjAbf51A, resulted in the loss of oligosaccharide 2 and the production of both xylose and arabinose, indicative of a disaccharide of xylose and arabinose. RESULTS 141 147 xylose chemical Treatment of pool 4 with the nonspecific arabinofuranosidase, CjAbf51A, resulted in the loss of oligosaccharide 2 and the production of both xylose and arabinose, indicative of a disaccharide of xylose and arabinose. RESULTS 152 161 arabinose chemical Treatment of pool 4 with the nonspecific arabinofuranosidase, CjAbf51A, resulted in the loss of oligosaccharide 2 and the production of both xylose and arabinose, indicative of a disaccharide of xylose and arabinose. RESULTS 179 191 disaccharide chemical Treatment of pool 4 with the nonspecific arabinofuranosidase, CjAbf51A, resulted in the loss of oligosaccharide 2 and the production of both xylose and arabinose, indicative of a disaccharide of xylose and arabinose. RESULTS 195 201 xylose chemical Treatment of pool 4 with the nonspecific arabinofuranosidase, CjAbf51A, resulted in the loss of oligosaccharide 2 and the production of both xylose and arabinose, indicative of a disaccharide of xylose and arabinose. RESULTS 206 215 arabinose chemical Treatment of pool 4 with the nonspecific arabinofuranosidase, CjAbf51A, resulted in the loss of oligosaccharide 2 and the production of both xylose and arabinose, indicative of a disaccharide of xylose and arabinose. RESULTS 28 44 β-1,3-xylosidase protein_type Incubation of pool 4 with a β-1,3-xylosidase (XynB) converted oligosaccharide 1 into xylose, demonstrating that this molecule is the disaccharide β-1,3-xylobiose. RESULTS 46 50 XynB protein Incubation of pool 4 with a β-1,3-xylosidase (XynB) converted oligosaccharide 1 into xylose, demonstrating that this molecule is the disaccharide β-1,3-xylobiose. RESULTS 62 77 oligosaccharide chemical Incubation of pool 4 with a β-1,3-xylosidase (XynB) converted oligosaccharide 1 into xylose, demonstrating that this molecule is the disaccharide β-1,3-xylobiose. RESULTS 85 91 xylose chemical Incubation of pool 4 with a β-1,3-xylosidase (XynB) converted oligosaccharide 1 into xylose, demonstrating that this molecule is the disaccharide β-1,3-xylobiose. RESULTS 133 145 disaccharide chemical Incubation of pool 4 with a β-1,3-xylosidase (XynB) converted oligosaccharide 1 into xylose, demonstrating that this molecule is the disaccharide β-1,3-xylobiose. RESULTS 146 161 β-1,3-xylobiose chemical Incubation of pool 4 with a β-1,3-xylosidase (XynB) converted oligosaccharide 1 into xylose, demonstrating that this molecule is the disaccharide β-1,3-xylobiose. RESULTS 45 70 β-1,4-specific xylosidase protein_type This view is supported by the inability of a β-1,4-specific xylosidase to hydrolyze oligosaccharide 1 or oligosaccharide 2 (data not shown). RESULTS 84 99 oligosaccharide chemical This view is supported by the inability of a β-1,4-specific xylosidase to hydrolyze oligosaccharide 1 or oligosaccharide 2 (data not shown). RESULTS 105 120 oligosaccharide chemical This view is supported by the inability of a β-1,4-specific xylosidase to hydrolyze oligosaccharide 1 or oligosaccharide 2 (data not shown). RESULTS 43 53 −2* pocket site The crucial importance of occupancy of the −2* pocket for catalytic competence is illustrated by the inability of the enzyme to hydrolyze linear β-1,4-xylooligosaccharides. RESULTS 145 171 β-1,4-xylooligosaccharides chemical The crucial importance of occupancy of the −2* pocket for catalytic competence is illustrated by the inability of the enzyme to hydrolyze linear β-1,4-xylooligosaccharides. RESULTS 18 27 Araf-Xylp chemical The generation of Araf-Xylp and Xyl-β-1,3-Xyl as reaction products demonstrates that occupancy of the −2 subsite is not essential for catalytic activity, which is in contrast to all endo-acting xylanases where this subsite plays a critical role in enzyme activity. RESULTS 32 45 Xyl-β-1,3-Xyl chemical The generation of Araf-Xylp and Xyl-β-1,3-Xyl as reaction products demonstrates that occupancy of the −2 subsite is not essential for catalytic activity, which is in contrast to all endo-acting xylanases where this subsite plays a critical role in enzyme activity. RESULTS 102 112 −2 subsite site The generation of Araf-Xylp and Xyl-β-1,3-Xyl as reaction products demonstrates that occupancy of the −2 subsite is not essential for catalytic activity, which is in contrast to all endo-acting xylanases where this subsite plays a critical role in enzyme activity. RESULTS 182 203 endo-acting xylanases protein_type The generation of Araf-Xylp and Xyl-β-1,3-Xyl as reaction products demonstrates that occupancy of the −2 subsite is not essential for catalytic activity, which is in contrast to all endo-acting xylanases where this subsite plays a critical role in enzyme activity. RESULTS 215 222 subsite site The generation of Araf-Xylp and Xyl-β-1,3-Xyl as reaction products demonstrates that occupancy of the −2 subsite is not essential for catalytic activity, which is in contrast to all endo-acting xylanases where this subsite plays a critical role in enzyme activity. RESULTS 34 37 −2* site Indeed, the data demonstrate that −2* plays a more important role in productive substrate binding than the −2 subsite. RESULTS 107 117 −2 subsite site Indeed, the data demonstrate that −2* plays a more important role in productive substrate binding than the −2 subsite. RESULTS 57 89 (Xyl-β-1,4)n-[β-1,3-Xyl/Ara]-Xyl chemical Unfortunately, the inability to generate highly purified (Xyl-β-1,4)n-[β-1,3-Xyl/Ara]-Xyl oligosaccharides from arabinoxylans prevented the precise binding energies at the negative subsites to be determined. RESULTS 90 106 oligosaccharides chemical Unfortunately, the inability to generate highly purified (Xyl-β-1,4)n-[β-1,3-Xyl/Ara]-Xyl oligosaccharides from arabinoxylans prevented the precise binding energies at the negative subsites to be determined. RESULTS 112 125 arabinoxylans chemical Unfortunately, the inability to generate highly purified (Xyl-β-1,4)n-[β-1,3-Xyl/Ara]-Xyl oligosaccharides from arabinoxylans prevented the precise binding energies at the negative subsites to be determined. RESULTS 22 34 disaccharide chemical Identification of the disaccharide reaction products generated from CX. FIG 68 70 CX chemical Identification of the disaccharide reaction products generated from CX. FIG 48 77 size exclusion chromatography experimental_method The smallest reaction products were purified by size exclusion chromatography and analyzed by HPAEC (A) and positive mode ESI-MS (B), respectively. FIG 94 99 HPAEC experimental_method The smallest reaction products were purified by size exclusion chromatography and analyzed by HPAEC (A) and positive mode ESI-MS (B), respectively. FIG 122 128 ESI-MS experimental_method The smallest reaction products were purified by size exclusion chromatography and analyzed by HPAEC (A) and positive mode ESI-MS (B), respectively. FIG 32 63 nonspecific arabinofuranosidase protein_type The samples were treated with a nonspecific arabinofuranosidase (CjAbf51A) and a GH3 xylosidase (XynB) that targeted β-1,3-xylosidic bonds. FIG 65 73 CjAbf51A protein The samples were treated with a nonspecific arabinofuranosidase (CjAbf51A) and a GH3 xylosidase (XynB) that targeted β-1,3-xylosidic bonds. FIG 81 95 GH3 xylosidase protein_type The samples were treated with a nonspecific arabinofuranosidase (CjAbf51A) and a GH3 xylosidase (XynB) that targeted β-1,3-xylosidic bonds. FIG 97 101 XynB protein The samples were treated with a nonspecific arabinofuranosidase (CjAbf51A) and a GH3 xylosidase (XynB) that targeted β-1,3-xylosidic bonds. FIG 3 9 xylose chemical X, xylose; A, arabinose. FIG 14 23 arabinose chemical X, xylose; A, arabinose. FIG 32 39 pentose chemical The m/z = 305 species denotes a pentose disaccharide as a sodium adduct [M + Na]+, whereas the m/z = 587 signal corresponds to an ESI-MS dimer of the pentose disaccharide also as a sodium adduct [2M + Na]+. FIG 40 52 disaccharide chemical The m/z = 305 species denotes a pentose disaccharide as a sodium adduct [M + Na]+, whereas the m/z = 587 signal corresponds to an ESI-MS dimer of the pentose disaccharide also as a sodium adduct [2M + Na]+. FIG 130 136 ESI-MS experimental_method The m/z = 305 species denotes a pentose disaccharide as a sodium adduct [M + Na]+, whereas the m/z = 587 signal corresponds to an ESI-MS dimer of the pentose disaccharide also as a sodium adduct [2M + Na]+. FIG 150 157 pentose chemical The m/z = 305 species denotes a pentose disaccharide as a sodium adduct [M + Na]+, whereas the m/z = 587 signal corresponds to an ESI-MS dimer of the pentose disaccharide also as a sodium adduct [2M + Na]+. FIG 158 170 disaccharide chemical The m/z = 305 species denotes a pentose disaccharide as a sodium adduct [M + Na]+, whereas the m/z = 587 signal corresponds to an ESI-MS dimer of the pentose disaccharide also as a sodium adduct [2M + Na]+. FIG 0 17 Crystal Structure evidence Crystal Structure of the Catalytic Module of CtXyl5A in Complex with Ligands RESULTS 25 41 Catalytic Module structure_element Crystal Structure of the Catalytic Module of CtXyl5A in Complex with Ligands RESULTS 45 52 CtXyl5A protein Crystal Structure of the Catalytic Module of CtXyl5A in Complex with Ligands RESULTS 53 68 in Complex with protein_state Crystal Structure of the Catalytic Module of CtXyl5A in Complex with Ligands RESULTS 69 76 Ligands chemical Crystal Structure of the Catalytic Module of CtXyl5A in Complex with Ligands RESULTS 69 76 CtXyl5A protein To understand the structural basis for the biochemical properties of CtXyl5A, the crystal structure of the enzyme with ligands that occupy the substrate binding cleft and the critical −2* subsite were sought. RESULTS 82 99 crystal structure evidence To understand the structural basis for the biochemical properties of CtXyl5A, the crystal structure of the enzyme with ligands that occupy the substrate binding cleft and the critical −2* subsite were sought. RESULTS 143 166 substrate binding cleft site To understand the structural basis for the biochemical properties of CtXyl5A, the crystal structure of the enzyme with ligands that occupy the substrate binding cleft and the critical −2* subsite were sought. RESULTS 184 195 −2* subsite site To understand the structural basis for the biochemical properties of CtXyl5A, the crystal structure of the enzyme with ligands that occupy the substrate binding cleft and the critical −2* subsite were sought. RESULTS 39 48 structure evidence The data presented in Fig. 3A show the structure of the CtXyl5A derivative CtGH5-CtCBM6 in complex with arabinose bound in the −2* pocket. RESULTS 56 63 CtXyl5A protein The data presented in Fig. 3A show the structure of the CtXyl5A derivative CtGH5-CtCBM6 in complex with arabinose bound in the −2* pocket. RESULTS 75 87 CtGH5-CtCBM6 structure_element The data presented in Fig. 3A show the structure of the CtXyl5A derivative CtGH5-CtCBM6 in complex with arabinose bound in the −2* pocket. RESULTS 88 103 in complex with protein_state The data presented in Fig. 3A show the structure of the CtXyl5A derivative CtGH5-CtCBM6 in complex with arabinose bound in the −2* pocket. RESULTS 104 113 arabinose chemical The data presented in Fig. 3A show the structure of the CtXyl5A derivative CtGH5-CtCBM6 in complex with arabinose bound in the −2* pocket. RESULTS 114 122 bound in protein_state The data presented in Fig. 3A show the structure of the CtXyl5A derivative CtGH5-CtCBM6 in complex with arabinose bound in the −2* pocket. RESULTS 127 137 −2* pocket site The data presented in Fig. 3A show the structure of the CtXyl5A derivative CtGH5-CtCBM6 in complex with arabinose bound in the −2* pocket. RESULTS 19 24 bound protein_state Interestingly, the bound arabinose was in the pyranose conformation rather than in its furanose form found in arabinoxylans. RESULTS 25 34 arabinose chemical Interestingly, the bound arabinose was in the pyranose conformation rather than in its furanose form found in arabinoxylans. RESULTS 46 54 pyranose chemical Interestingly, the bound arabinose was in the pyranose conformation rather than in its furanose form found in arabinoxylans. RESULTS 87 95 furanose chemical Interestingly, the bound arabinose was in the pyranose conformation rather than in its furanose form found in arabinoxylans. RESULTS 110 123 arabinoxylans chemical Interestingly, the bound arabinose was in the pyranose conformation rather than in its furanose form found in arabinoxylans. RESULTS 25 36 active site site O1 was facing toward the active site −1 subsite, indicative of the bound arabinose being in the right orientation to be linked to the xylan backbone via an α-1,3 linkage. RESULTS 37 47 −1 subsite site O1 was facing toward the active site −1 subsite, indicative of the bound arabinose being in the right orientation to be linked to the xylan backbone via an α-1,3 linkage. RESULTS 67 72 bound protein_state O1 was facing toward the active site −1 subsite, indicative of the bound arabinose being in the right orientation to be linked to the xylan backbone via an α-1,3 linkage. RESULTS 73 82 arabinose chemical O1 was facing toward the active site −1 subsite, indicative of the bound arabinose being in the right orientation to be linked to the xylan backbone via an α-1,3 linkage. RESULTS 134 139 xylan chemical O1 was facing toward the active site −1 subsite, indicative of the bound arabinose being in the right orientation to be linked to the xylan backbone via an α-1,3 linkage. RESULTS 43 47 Arap chemical As discussed on below, the axial O4 of the Arap did not interact with the −2* subsite, suggesting that the pocket might be capable of binding a xylose molecule. RESULTS 74 85 −2* subsite site As discussed on below, the axial O4 of the Arap did not interact with the −2* subsite, suggesting that the pocket might be capable of binding a xylose molecule. RESULTS 107 113 pocket site As discussed on below, the axial O4 of the Arap did not interact with the −2* subsite, suggesting that the pocket might be capable of binding a xylose molecule. RESULTS 144 150 xylose chemical As discussed on below, the axial O4 of the Arap did not interact with the −2* subsite, suggesting that the pocket might be capable of binding a xylose molecule. RESULTS 8 15 soaking experimental_method Indeed, soaking apo crystals with xylose showed that the pentose sugar also bound in the −2* subsite in its pyranose conformation (Fig. 3B). RESULTS 16 19 apo protein_state Indeed, soaking apo crystals with xylose showed that the pentose sugar also bound in the −2* subsite in its pyranose conformation (Fig. 3B). RESULTS 20 28 crystals evidence Indeed, soaking apo crystals with xylose showed that the pentose sugar also bound in the −2* subsite in its pyranose conformation (Fig. 3B). RESULTS 34 40 xylose chemical Indeed, soaking apo crystals with xylose showed that the pentose sugar also bound in the −2* subsite in its pyranose conformation (Fig. 3B). RESULTS 57 64 pentose chemical Indeed, soaking apo crystals with xylose showed that the pentose sugar also bound in the −2* subsite in its pyranose conformation (Fig. 3B). RESULTS 65 70 sugar chemical Indeed, soaking apo crystals with xylose showed that the pentose sugar also bound in the −2* subsite in its pyranose conformation (Fig. 3B). RESULTS 76 84 bound in protein_state Indeed, soaking apo crystals with xylose showed that the pentose sugar also bound in the −2* subsite in its pyranose conformation (Fig. 3B). RESULTS 89 100 −2* subsite site Indeed, soaking apo crystals with xylose showed that the pentose sugar also bound in the −2* subsite in its pyranose conformation (Fig. 3B). RESULTS 108 116 pyranose chemical Indeed, soaking apo crystals with xylose showed that the pentose sugar also bound in the −2* subsite in its pyranose conformation (Fig. 3B). RESULTS 6 24 crystal structures evidence These crystal structures support the biochemical data presented above showing that the enzyme generated β-1,3-xylobiose from CX, which would require the disaccharide to bind at the −1 and −2* subsites. RESULTS 104 119 β-1,3-xylobiose chemical These crystal structures support the biochemical data presented above showing that the enzyme generated β-1,3-xylobiose from CX, which would require the disaccharide to bind at the −1 and −2* subsites. RESULTS 125 127 CX chemical These crystal structures support the biochemical data presented above showing that the enzyme generated β-1,3-xylobiose from CX, which would require the disaccharide to bind at the −1 and −2* subsites. RESULTS 153 165 disaccharide chemical These crystal structures support the biochemical data presented above showing that the enzyme generated β-1,3-xylobiose from CX, which would require the disaccharide to bind at the −1 and −2* subsites. RESULTS 181 200 −1 and −2* subsites site These crystal structures support the biochemical data presented above showing that the enzyme generated β-1,3-xylobiose from CX, which would require the disaccharide to bind at the −1 and −2* subsites. RESULTS 41 57 co-crystallizing experimental_method A third product complex was generated by co-crystallizing the nucleophile inactive mutant CtGH5E279S-CtCBM6 with a WAX-derived oligosaccharide (Fig. 3C). RESULTS 62 82 nucleophile inactive protein_state A third product complex was generated by co-crystallizing the nucleophile inactive mutant CtGH5E279S-CtCBM6 with a WAX-derived oligosaccharide (Fig. 3C). RESULTS 83 89 mutant protein_state A third product complex was generated by co-crystallizing the nucleophile inactive mutant CtGH5E279S-CtCBM6 with a WAX-derived oligosaccharide (Fig. 3C). RESULTS 90 100 CtGH5E279S mutant A third product complex was generated by co-crystallizing the nucleophile inactive mutant CtGH5E279S-CtCBM6 with a WAX-derived oligosaccharide (Fig. 3C). RESULTS 101 107 CtCBM6 structure_element A third product complex was generated by co-crystallizing the nucleophile inactive mutant CtGH5E279S-CtCBM6 with a WAX-derived oligosaccharide (Fig. 3C). RESULTS 115 118 WAX chemical A third product complex was generated by co-crystallizing the nucleophile inactive mutant CtGH5E279S-CtCBM6 with a WAX-derived oligosaccharide (Fig. 3C). RESULTS 127 142 oligosaccharide chemical A third product complex was generated by co-crystallizing the nucleophile inactive mutant CtGH5E279S-CtCBM6 with a WAX-derived oligosaccharide (Fig. 3C). RESULTS 20 35 pentasaccharide chemical The data revealed a pentasaccharide bound to the enzyme, comprising β-1,4-xylotetraose with an Araf linked α-1,3 to the reducing end xylose. RESULTS 36 44 bound to protein_state The data revealed a pentasaccharide bound to the enzyme, comprising β-1,4-xylotetraose with an Araf linked α-1,3 to the reducing end xylose. RESULTS 68 86 β-1,4-xylotetraose chemical The data revealed a pentasaccharide bound to the enzyme, comprising β-1,4-xylotetraose with an Araf linked α-1,3 to the reducing end xylose. RESULTS 95 99 Araf chemical The data revealed a pentasaccharide bound to the enzyme, comprising β-1,4-xylotetraose with an Araf linked α-1,3 to the reducing end xylose. RESULTS 133 139 xylose chemical The data revealed a pentasaccharide bound to the enzyme, comprising β-1,4-xylotetraose with an Araf linked α-1,3 to the reducing end xylose. RESULTS 4 16 xylotetraose chemical The xylotetraose was positioned in subsites −1 to −4 and the Araf in the −2* pocket. RESULTS 35 52 subsites −1 to −4 site The xylotetraose was positioned in subsites −1 to −4 and the Araf in the −2* pocket. RESULTS 61 65 Araf chemical The xylotetraose was positioned in subsites −1 to −4 and the Araf in the −2* pocket. RESULTS 73 83 −2* pocket site The xylotetraose was positioned in subsites −1 to −4 and the Araf in the −2* pocket. RESULTS 22 32 structures evidence Analysis of the three structures showed that O1, O2, O3, and the endocyclic oxygen occupied identical positions in the Arap, Araf, and Xylp ligands bound in the −2* subsite and thus made identical interactions with the pocket. RESULTS 119 123 Arap chemical Analysis of the three structures showed that O1, O2, O3, and the endocyclic oxygen occupied identical positions in the Arap, Araf, and Xylp ligands bound in the −2* subsite and thus made identical interactions with the pocket. RESULTS 125 129 Araf chemical Analysis of the three structures showed that O1, O2, O3, and the endocyclic oxygen occupied identical positions in the Arap, Araf, and Xylp ligands bound in the −2* subsite and thus made identical interactions with the pocket. RESULTS 135 139 Xylp chemical Analysis of the three structures showed that O1, O2, O3, and the endocyclic oxygen occupied identical positions in the Arap, Araf, and Xylp ligands bound in the −2* subsite and thus made identical interactions with the pocket. RESULTS 148 156 bound in protein_state Analysis of the three structures showed that O1, O2, O3, and the endocyclic oxygen occupied identical positions in the Arap, Araf, and Xylp ligands bound in the −2* subsite and thus made identical interactions with the pocket. RESULTS 161 172 −2* subsite site Analysis of the three structures showed that O1, O2, O3, and the endocyclic oxygen occupied identical positions in the Arap, Araf, and Xylp ligands bound in the −2* subsite and thus made identical interactions with the pocket. RESULTS 219 225 pocket site Analysis of the three structures showed that O1, O2, O3, and the endocyclic oxygen occupied identical positions in the Arap, Araf, and Xylp ligands bound in the −2* subsite and thus made identical interactions with the pocket. RESULTS 11 24 polar contact bond_interaction O1 makes a polar contact with Nδ2 of Asn139, O2 is within hydrogen bonding distance with Oδ1 of Asn139 and the backbone N of Asn135, and O3 interacts with the N of Gly136 and Oϵ2 of Glu68. RESULTS 37 43 Asn139 residue_name_number O1 makes a polar contact with Nδ2 of Asn139, O2 is within hydrogen bonding distance with Oδ1 of Asn139 and the backbone N of Asn135, and O3 interacts with the N of Gly136 and Oϵ2 of Glu68. RESULTS 58 74 hydrogen bonding bond_interaction O1 makes a polar contact with Nδ2 of Asn139, O2 is within hydrogen bonding distance with Oδ1 of Asn139 and the backbone N of Asn135, and O3 interacts with the N of Gly136 and Oϵ2 of Glu68. RESULTS 96 102 Asn139 residue_name_number O1 makes a polar contact with Nδ2 of Asn139, O2 is within hydrogen bonding distance with Oδ1 of Asn139 and the backbone N of Asn135, and O3 interacts with the N of Gly136 and Oϵ2 of Glu68. RESULTS 125 131 Asn135 residue_name_number O1 makes a polar contact with Nδ2 of Asn139, O2 is within hydrogen bonding distance with Oδ1 of Asn139 and the backbone N of Asn135, and O3 interacts with the N of Gly136 and Oϵ2 of Glu68. RESULTS 164 170 Gly136 residue_name_number O1 makes a polar contact with Nδ2 of Asn139, O2 is within hydrogen bonding distance with Oδ1 of Asn139 and the backbone N of Asn135, and O3 interacts with the N of Gly136 and Oϵ2 of Glu68. RESULTS 182 187 Glu68 residue_name_number O1 makes a polar contact with Nδ2 of Asn139, O2 is within hydrogen bonding distance with Oδ1 of Asn139 and the backbone N of Asn135, and O3 interacts with the N of Gly136 and Oϵ2 of Glu68. RESULTS 15 19 Arap chemical Although O4 of Arap does not make a direct interaction with the enzyme, O4 and O5 of Xylp and Araf, respectively, form hydrogen bonds with Oϵ1 of Glu68. RESULTS 85 89 Xylp chemical Although O4 of Arap does not make a direct interaction with the enzyme, O4 and O5 of Xylp and Araf, respectively, form hydrogen bonds with Oϵ1 of Glu68. RESULTS 94 98 Araf chemical Although O4 of Arap does not make a direct interaction with the enzyme, O4 and O5 of Xylp and Araf, respectively, form hydrogen bonds with Oϵ1 of Glu68. RESULTS 119 133 hydrogen bonds bond_interaction Although O4 of Arap does not make a direct interaction with the enzyme, O4 and O5 of Xylp and Araf, respectively, form hydrogen bonds with Oϵ1 of Glu68. RESULTS 146 151 Glu68 residue_name_number Although O4 of Arap does not make a direct interaction with the enzyme, O4 and O5 of Xylp and Araf, respectively, form hydrogen bonds with Oϵ1 of Glu68. RESULTS 8 13 Tyr92 residue_name_number Finally Tyr92 makes apolar parallel interactions with the pyranose or furanose rings of the three sugars. RESULTS 27 48 parallel interactions bond_interaction Finally Tyr92 makes apolar parallel interactions with the pyranose or furanose rings of the three sugars. RESULTS 58 66 pyranose chemical Finally Tyr92 makes apolar parallel interactions with the pyranose or furanose rings of the three sugars. RESULTS 70 78 furanose chemical Finally Tyr92 makes apolar parallel interactions with the pyranose or furanose rings of the three sugars. RESULTS 74 85 −2* subsite site Representation of the residues involved in the ligands recognition at the −2* subsite. FIG 63 81 catalytic residues site Interacting residues are represented as stick in blue, and the catalytic residues and the mutated glutamate (into a serine) are in magenta. FIG 90 97 mutated experimental_method Interacting residues are represented as stick in blue, and the catalytic residues and the mutated glutamate (into a serine) are in magenta. FIG 98 107 glutamate residue_name Interacting residues are represented as stick in blue, and the catalytic residues and the mutated glutamate (into a serine) are in magenta. FIG 116 122 serine residue_name Interacting residues are represented as stick in blue, and the catalytic residues and the mutated glutamate (into a serine) are in magenta. FIG 3 13 CtGH5-CBM6 structure_element A, CtGH5-CBM6 in complex with an arabinopyranose. FIG 14 29 in complex with protein_state A, CtGH5-CBM6 in complex with an arabinopyranose. FIG 33 48 arabinopyranose chemical A, CtGH5-CBM6 in complex with an arabinopyranose. FIG 3 13 CtGH5-CBM6 structure_element B, CtGH5-CBM6 in complex with a xylopyranose. FIG 14 29 in complex with protein_state B, CtGH5-CBM6 in complex with a xylopyranose. FIG 32 44 xylopyranose chemical B, CtGH5-CBM6 in complex with a xylopyranose. FIG 3 13 CtGH5E279S mutant C, CtGH5E279S-CBM6 in complex with a pentasaccharide (β1,4-xylotetraose with an l-Araf linked α1,3 to the reducing end xylose). FIG 14 18 CBM6 structure_element C, CtGH5E279S-CBM6 in complex with a pentasaccharide (β1,4-xylotetraose with an l-Araf linked α1,3 to the reducing end xylose). FIG 19 34 in complex with protein_state C, CtGH5E279S-CBM6 in complex with a pentasaccharide (β1,4-xylotetraose with an l-Araf linked α1,3 to the reducing end xylose). FIG 37 52 pentasaccharide chemical C, CtGH5E279S-CBM6 in complex with a pentasaccharide (β1,4-xylotetraose with an l-Araf linked α1,3 to the reducing end xylose). FIG 54 71 β1,4-xylotetraose chemical C, CtGH5E279S-CBM6 in complex with a pentasaccharide (β1,4-xylotetraose with an l-Araf linked α1,3 to the reducing end xylose). FIG 80 86 l-Araf chemical C, CtGH5E279S-CBM6 in complex with a pentasaccharide (β1,4-xylotetraose with an l-Araf linked α1,3 to the reducing end xylose). FIG 119 125 xylose chemical C, CtGH5E279S-CBM6 in complex with a pentasaccharide (β1,4-xylotetraose with an l-Araf linked α1,3 to the reducing end xylose). FIG 4 9 xylan chemical The xylan backbone is shown transparently for more clarity. FIG 0 9 Densities evidence Densities shown in blue are RefMac maximum-likelihood σA-weighted 2Fo − Fc at 1.5 σ. FIG 35 83 maximum-likelihood σA-weighted 2Fo − Fc at 1.5 σ evidence Densities shown in blue are RefMac maximum-likelihood σA-weighted 2Fo − Fc at 1.5 σ. FIG 98 108 −2* pocket site The importance of the interactions between the ligands and the side chains of the residues in the −2* pocket were evaluated by alanine substitution of these amino acids. RESULTS 127 147 alanine substitution experimental_method The importance of the interactions between the ligands and the side chains of the residues in the −2* pocket were evaluated by alanine substitution of these amino acids. RESULTS 4 11 mutants protein_state The mutants E68A, Y92A, and N139A were all inactive (Table 1), demonstrating the importance of the interactions of these residues with the substrate and reinforcing the critical role the −2* subsite plays in the activity of the enzyme. RESULTS 12 16 E68A mutant The mutants E68A, Y92A, and N139A were all inactive (Table 1), demonstrating the importance of the interactions of these residues with the substrate and reinforcing the critical role the −2* subsite plays in the activity of the enzyme. RESULTS 18 22 Y92A mutant The mutants E68A, Y92A, and N139A were all inactive (Table 1), demonstrating the importance of the interactions of these residues with the substrate and reinforcing the critical role the −2* subsite plays in the activity of the enzyme. RESULTS 28 33 N139A mutant The mutants E68A, Y92A, and N139A were all inactive (Table 1), demonstrating the importance of the interactions of these residues with the substrate and reinforcing the critical role the −2* subsite plays in the activity of the enzyme. RESULTS 43 51 inactive protein_state The mutants E68A, Y92A, and N139A were all inactive (Table 1), demonstrating the importance of the interactions of these residues with the substrate and reinforcing the critical role the −2* subsite plays in the activity of the enzyme. RESULTS 187 198 −2* subsite site The mutants E68A, Y92A, and N139A were all inactive (Table 1), demonstrating the importance of the interactions of these residues with the substrate and reinforcing the critical role the −2* subsite plays in the activity of the enzyme. RESULTS 0 5 N135A mutant N135A retained wild type activity because the O2 of the sugars interacts with the backbone N of Asn135 and not with the side chain. RESULTS 15 24 wild type protein_state N135A retained wild type activity because the O2 of the sugars interacts with the backbone N of Asn135 and not with the side chain. RESULTS 96 102 Asn135 residue_name_number N135A retained wild type activity because the O2 of the sugars interacts with the backbone N of Asn135 and not with the side chain. RESULTS 25 29 Xylp chemical Because the hydroxyls of Xylp or Araf in the −2* pocket are not solvent-exposed, the active site of the arabinoxylanase can only bind to xylose residues that contain a single xylose or arabinose O3 decoration. RESULTS 33 37 Araf chemical Because the hydroxyls of Xylp or Araf in the −2* pocket are not solvent-exposed, the active site of the arabinoxylanase can only bind to xylose residues that contain a single xylose or arabinose O3 decoration. RESULTS 45 55 −2* pocket site Because the hydroxyls of Xylp or Araf in the −2* pocket are not solvent-exposed, the active site of the arabinoxylanase can only bind to xylose residues that contain a single xylose or arabinose O3 decoration. RESULTS 64 79 solvent-exposed protein_state Because the hydroxyls of Xylp or Araf in the −2* pocket are not solvent-exposed, the active site of the arabinoxylanase can only bind to xylose residues that contain a single xylose or arabinose O3 decoration. RESULTS 85 96 active site site Because the hydroxyls of Xylp or Araf in the −2* pocket are not solvent-exposed, the active site of the arabinoxylanase can only bind to xylose residues that contain a single xylose or arabinose O3 decoration. RESULTS 104 119 arabinoxylanase protein_type Because the hydroxyls of Xylp or Araf in the −2* pocket are not solvent-exposed, the active site of the arabinoxylanase can only bind to xylose residues that contain a single xylose or arabinose O3 decoration. RESULTS 137 143 xylose chemical Because the hydroxyls of Xylp or Araf in the −2* pocket are not solvent-exposed, the active site of the arabinoxylanase can only bind to xylose residues that contain a single xylose or arabinose O3 decoration. RESULTS 175 181 xylose chemical Because the hydroxyls of Xylp or Araf in the −2* pocket are not solvent-exposed, the active site of the arabinoxylanase can only bind to xylose residues that contain a single xylose or arabinose O3 decoration. RESULTS 185 194 arabinose chemical Because the hydroxyls of Xylp or Araf in the −2* pocket are not solvent-exposed, the active site of the arabinoxylanase can only bind to xylose residues that contain a single xylose or arabinose O3 decoration. RESULTS 25 29 kcat evidence This may explain why the kcat/Km for CtXyl5A against WAX was 2-fold higher than against CX (Table 1). RESULTS 30 32 Km evidence This may explain why the kcat/Km for CtXyl5A against WAX was 2-fold higher than against CX (Table 1). RESULTS 37 44 CtXyl5A protein This may explain why the kcat/Km for CtXyl5A against WAX was 2-fold higher than against CX (Table 1). RESULTS 53 56 WAX chemical This may explain why the kcat/Km for CtXyl5A against WAX was 2-fold higher than against CX (Table 1). RESULTS 88 90 CX chemical This may explain why the kcat/Km for CtXyl5A against WAX was 2-fold higher than against CX (Table 1). RESULTS 0 3 WAX chemical WAX is likely to have a higher concentration of single Araf decorations compared with CX and thus contain more substrate available to the arabinoxylanase. RESULTS 55 59 Araf chemical WAX is likely to have a higher concentration of single Araf decorations compared with CX and thus contain more substrate available to the arabinoxylanase. RESULTS 86 88 CX chemical WAX is likely to have a higher concentration of single Araf decorations compared with CX and thus contain more substrate available to the arabinoxylanase. RESULTS 138 153 arabinoxylanase protein_type WAX is likely to have a higher concentration of single Araf decorations compared with CX and thus contain more substrate available to the arabinoxylanase. RESULTS 7 18 active site site In the active site of CtXyl5A the α-d-Xylp, which is in its relaxed 4C1 conformation, makes the following interactions with the enzyme (Fig. 4, A–C): O1 hydrogen bonds with the Nδ1 of His253 and Oϵ2 of Glu171 (catalytic acid-base) and makes a possible weak polar contact with the OH of Tyr255 and Oγ of Ser279 (mutation of the catalytic nucleophile); O2 hydrogen bonds with Nδ2 of Asn170 and OH of Tyr92. RESULTS 22 29 CtXyl5A protein In the active site of CtXyl5A the α-d-Xylp, which is in its relaxed 4C1 conformation, makes the following interactions with the enzyme (Fig. 4, A–C): O1 hydrogen bonds with the Nδ1 of His253 and Oϵ2 of Glu171 (catalytic acid-base) and makes a possible weak polar contact with the OH of Tyr255 and Oγ of Ser279 (mutation of the catalytic nucleophile); O2 hydrogen bonds with Nδ2 of Asn170 and OH of Tyr92. RESULTS 34 42 α-d-Xylp chemical In the active site of CtXyl5A the α-d-Xylp, which is in its relaxed 4C1 conformation, makes the following interactions with the enzyme (Fig. 4, A–C): O1 hydrogen bonds with the Nδ1 of His253 and Oϵ2 of Glu171 (catalytic acid-base) and makes a possible weak polar contact with the OH of Tyr255 and Oγ of Ser279 (mutation of the catalytic nucleophile); O2 hydrogen bonds with Nδ2 of Asn170 and OH of Tyr92. RESULTS 153 167 hydrogen bonds bond_interaction In the active site of CtXyl5A the α-d-Xylp, which is in its relaxed 4C1 conformation, makes the following interactions with the enzyme (Fig. 4, A–C): O1 hydrogen bonds with the Nδ1 of His253 and Oϵ2 of Glu171 (catalytic acid-base) and makes a possible weak polar contact with the OH of Tyr255 and Oγ of Ser279 (mutation of the catalytic nucleophile); O2 hydrogen bonds with Nδ2 of Asn170 and OH of Tyr92. RESULTS 184 190 His253 residue_name_number In the active site of CtXyl5A the α-d-Xylp, which is in its relaxed 4C1 conformation, makes the following interactions with the enzyme (Fig. 4, A–C): O1 hydrogen bonds with the Nδ1 of His253 and Oϵ2 of Glu171 (catalytic acid-base) and makes a possible weak polar contact with the OH of Tyr255 and Oγ of Ser279 (mutation of the catalytic nucleophile); O2 hydrogen bonds with Nδ2 of Asn170 and OH of Tyr92. RESULTS 202 208 Glu171 residue_name_number In the active site of CtXyl5A the α-d-Xylp, which is in its relaxed 4C1 conformation, makes the following interactions with the enzyme (Fig. 4, A–C): O1 hydrogen bonds with the Nδ1 of His253 and Oϵ2 of Glu171 (catalytic acid-base) and makes a possible weak polar contact with the OH of Tyr255 and Oγ of Ser279 (mutation of the catalytic nucleophile); O2 hydrogen bonds with Nδ2 of Asn170 and OH of Tyr92. RESULTS 257 270 polar contact bond_interaction In the active site of CtXyl5A the α-d-Xylp, which is in its relaxed 4C1 conformation, makes the following interactions with the enzyme (Fig. 4, A–C): O1 hydrogen bonds with the Nδ1 of His253 and Oϵ2 of Glu171 (catalytic acid-base) and makes a possible weak polar contact with the OH of Tyr255 and Oγ of Ser279 (mutation of the catalytic nucleophile); O2 hydrogen bonds with Nδ2 of Asn170 and OH of Tyr92. RESULTS 286 292 Tyr255 residue_name_number In the active site of CtXyl5A the α-d-Xylp, which is in its relaxed 4C1 conformation, makes the following interactions with the enzyme (Fig. 4, A–C): O1 hydrogen bonds with the Nδ1 of His253 and Oϵ2 of Glu171 (catalytic acid-base) and makes a possible weak polar contact with the OH of Tyr255 and Oγ of Ser279 (mutation of the catalytic nucleophile); O2 hydrogen bonds with Nδ2 of Asn170 and OH of Tyr92. RESULTS 303 309 Ser279 residue_name_number In the active site of CtXyl5A the α-d-Xylp, which is in its relaxed 4C1 conformation, makes the following interactions with the enzyme (Fig. 4, A–C): O1 hydrogen bonds with the Nδ1 of His253 and Oϵ2 of Glu171 (catalytic acid-base) and makes a possible weak polar contact with the OH of Tyr255 and Oγ of Ser279 (mutation of the catalytic nucleophile); O2 hydrogen bonds with Nδ2 of Asn170 and OH of Tyr92. RESULTS 354 368 hydrogen bonds bond_interaction In the active site of CtXyl5A the α-d-Xylp, which is in its relaxed 4C1 conformation, makes the following interactions with the enzyme (Fig. 4, A–C): O1 hydrogen bonds with the Nδ1 of His253 and Oϵ2 of Glu171 (catalytic acid-base) and makes a possible weak polar contact with the OH of Tyr255 and Oγ of Ser279 (mutation of the catalytic nucleophile); O2 hydrogen bonds with Nδ2 of Asn170 and OH of Tyr92. RESULTS 381 387 Asn170 residue_name_number In the active site of CtXyl5A the α-d-Xylp, which is in its relaxed 4C1 conformation, makes the following interactions with the enzyme (Fig. 4, A–C): O1 hydrogen bonds with the Nδ1 of His253 and Oϵ2 of Glu171 (catalytic acid-base) and makes a possible weak polar contact with the OH of Tyr255 and Oγ of Ser279 (mutation of the catalytic nucleophile); O2 hydrogen bonds with Nδ2 of Asn170 and OH of Tyr92. RESULTS 398 403 Tyr92 residue_name_number In the active site of CtXyl5A the α-d-Xylp, which is in its relaxed 4C1 conformation, makes the following interactions with the enzyme (Fig. 4, A–C): O1 hydrogen bonds with the Nδ1 of His253 and Oϵ2 of Glu171 (catalytic acid-base) and makes a possible weak polar contact with the OH of Tyr255 and Oγ of Ser279 (mutation of the catalytic nucleophile); O2 hydrogen bonds with Nδ2 of Asn170 and OH of Tyr92. RESULTS 14 18 Araf chemical O3 (O1 of the Araf at the −2* subsite) makes a polar contact with Nδ2 of Asn139; the endocyclic oxygen hydrogens bonds with the OH of Tyr255. RESULTS 26 37 −2* subsite site O3 (O1 of the Araf at the −2* subsite) makes a polar contact with Nδ2 of Asn139; the endocyclic oxygen hydrogens bonds with the OH of Tyr255. RESULTS 47 60 polar contact bond_interaction O3 (O1 of the Araf at the −2* subsite) makes a polar contact with Nδ2 of Asn139; the endocyclic oxygen hydrogens bonds with the OH of Tyr255. RESULTS 73 79 Asn139 residue_name_number O3 (O1 of the Araf at the −2* subsite) makes a polar contact with Nδ2 of Asn139; the endocyclic oxygen hydrogens bonds with the OH of Tyr255. RESULTS 103 118 hydrogens bonds bond_interaction O3 (O1 of the Araf at the −2* subsite) makes a polar contact with Nδ2 of Asn139; the endocyclic oxygen hydrogens bonds with the OH of Tyr255. RESULTS 134 140 Tyr255 residue_name_number O3 (O1 of the Araf at the −2* subsite) makes a polar contact with Nδ2 of Asn139; the endocyclic oxygen hydrogens bonds with the OH of Tyr255. RESULTS 4 8 Xylp chemical The Xylp in the active site makes strong parallel apolar interactions with Phe310. RESULTS 16 27 active site site The Xylp in the active site makes strong parallel apolar interactions with Phe310. RESULTS 41 69 parallel apolar interactions bond_interaction The Xylp in the active site makes strong parallel apolar interactions with Phe310. RESULTS 75 81 Phe310 residue_name_number The Xylp in the active site makes strong parallel apolar interactions with Phe310. RESULTS 29 40 active site site Substrate recognition in the active site is conserved between CtXyl5A and the closest GH5 structural homolog, the endoglucanase BaCel5A (PDB code 1qi2) as noted previously. RESULTS 44 53 conserved protein_state Substrate recognition in the active site is conserved between CtXyl5A and the closest GH5 structural homolog, the endoglucanase BaCel5A (PDB code 1qi2) as noted previously. RESULTS 62 69 CtXyl5A protein Substrate recognition in the active site is conserved between CtXyl5A and the closest GH5 structural homolog, the endoglucanase BaCel5A (PDB code 1qi2) as noted previously. RESULTS 86 89 GH5 protein_type Substrate recognition in the active site is conserved between CtXyl5A and the closest GH5 structural homolog, the endoglucanase BaCel5A (PDB code 1qi2) as noted previously. RESULTS 114 127 endoglucanase protein_type Substrate recognition in the active site is conserved between CtXyl5A and the closest GH5 structural homolog, the endoglucanase BaCel5A (PDB code 1qi2) as noted previously. RESULTS 128 135 BaCel5A protein Substrate recognition in the active site is conserved between CtXyl5A and the closest GH5 structural homolog, the endoglucanase BaCel5A (PDB code 1qi2) as noted previously. RESULTS 51 68 negative subsites site Comparison of the ligand recognition at the distal negative subsites between CtGH5E279S-CBM6, the cellulase BaCel5A, and the xylanase GH10. FIG 77 87 CtGH5E279S mutant Comparison of the ligand recognition at the distal negative subsites between CtGH5E279S-CBM6, the cellulase BaCel5A, and the xylanase GH10. FIG 88 92 CBM6 structure_element Comparison of the ligand recognition at the distal negative subsites between CtGH5E279S-CBM6, the cellulase BaCel5A, and the xylanase GH10. FIG 98 107 cellulase protein_type Comparison of the ligand recognition at the distal negative subsites between CtGH5E279S-CBM6, the cellulase BaCel5A, and the xylanase GH10. FIG 108 115 BaCel5A protein Comparison of the ligand recognition at the distal negative subsites between CtGH5E279S-CBM6, the cellulase BaCel5A, and the xylanase GH10. FIG 125 133 xylanase protein_type Comparison of the ligand recognition at the distal negative subsites between CtGH5E279S-CBM6, the cellulase BaCel5A, and the xylanase GH10. FIG 134 138 GH10 protein_type Comparison of the ligand recognition at the distal negative subsites between CtGH5E279S-CBM6, the cellulase BaCel5A, and the xylanase GH10. FIG 10 20 CtGH5E279S mutant A–C show CtGH5E279S-CBM6 is in complex with a pentasaccharide (β1,4-xylotetraose with an l-Araf linked α1,3 to the reducing end xylose). FIG 29 44 in complex with protein_state A–C show CtGH5E279S-CBM6 is in complex with a pentasaccharide (β1,4-xylotetraose with an l-Araf linked α1,3 to the reducing end xylose). FIG 47 62 pentasaccharide chemical A–C show CtGH5E279S-CBM6 is in complex with a pentasaccharide (β1,4-xylotetraose with an l-Araf linked α1,3 to the reducing end xylose). FIG 64 81 β1,4-xylotetraose chemical A–C show CtGH5E279S-CBM6 is in complex with a pentasaccharide (β1,4-xylotetraose with an l-Araf linked α1,3 to the reducing end xylose). FIG 90 96 l-Araf chemical A–C show CtGH5E279S-CBM6 is in complex with a pentasaccharide (β1,4-xylotetraose with an l-Araf linked α1,3 to the reducing end xylose). FIG 129 135 xylose chemical A–C show CtGH5E279S-CBM6 is in complex with a pentasaccharide (β1,4-xylotetraose with an l-Araf linked α1,3 to the reducing end xylose). FIG 44 60 hydrogen bonding bond_interaction A, Poseview representation highlighting the hydrogen bonding and the hydrophobic interactions that occur in the negative subsites. FIG 69 93 hydrophobic interactions bond_interaction A, Poseview representation highlighting the hydrogen bonding and the hydrophobic interactions that occur in the negative subsites. FIG 112 129 negative subsites site A, Poseview representation highlighting the hydrogen bonding and the hydrophobic interactions that occur in the negative subsites. FIG 3 10 density evidence C, density of the ligand shown in blue is RefMac maximum-likelihood σA-weighted 2Fo − Fc at 1.5 σ. FIG 49 97 maximum-likelihood σA-weighted 2Fo − Fc at 1.5 σ evidence C, density of the ligand shown in blue is RefMac maximum-likelihood σA-weighted 2Fo − Fc at 1.5 σ. FIG 16 23 BaCel5A protein D and E display BaCel5A in complex with deoxy-2-fluoro-β-d-cellotrioside (PDB code 1qi2), and F and G show CmXyn10B in complex with a xylotriose (PDB code 1uqy). FIG 24 39 in complex with protein_state D and E display BaCel5A in complex with deoxy-2-fluoro-β-d-cellotrioside (PDB code 1qi2), and F and G show CmXyn10B in complex with a xylotriose (PDB code 1uqy). FIG 40 72 deoxy-2-fluoro-β-d-cellotrioside chemical D and E display BaCel5A in complex with deoxy-2-fluoro-β-d-cellotrioside (PDB code 1qi2), and F and G show CmXyn10B in complex with a xylotriose (PDB code 1uqy). FIG 107 115 CmXyn10B protein D and E display BaCel5A in complex with deoxy-2-fluoro-β-d-cellotrioside (PDB code 1qi2), and F and G show CmXyn10B in complex with a xylotriose (PDB code 1uqy). FIG 116 131 in complex with protein_state D and E display BaCel5A in complex with deoxy-2-fluoro-β-d-cellotrioside (PDB code 1qi2), and F and G show CmXyn10B in complex with a xylotriose (PDB code 1uqy). FIG 134 144 xylotriose chemical D and E display BaCel5A in complex with deoxy-2-fluoro-β-d-cellotrioside (PDB code 1qi2), and F and G show CmXyn10B in complex with a xylotriose (PDB code 1uqy). FIG 41 51 CtGH5E279S mutant B, D, and F are surface representations (CtGH5E279S-CBM6 in gray, BaCel5A in cyan, and the xylanase GH10 in light brown). FIG 66 73 BaCel5A protein B, D, and F are surface representations (CtGH5E279S-CBM6 in gray, BaCel5A in cyan, and the xylanase GH10 in light brown). FIG 91 99 xylanase protein_type B, D, and F are surface representations (CtGH5E279S-CBM6 in gray, BaCel5A in cyan, and the xylanase GH10 in light brown). FIG 100 104 GH10 protein_type B, D, and F are surface representations (CtGH5E279S-CBM6 in gray, BaCel5A in cyan, and the xylanase GH10 in light brown). FIG 31 45 hydrogen bonds bond_interaction The black dashes represent the hydrogen bonds. FIG 31 45 hydrogen bonds bond_interaction The black dashes represent the hydrogen bonds. FIG 16 23 CtXyl5A protein The capacity of CtXyl5A to act on the highly decorated xylan CX indicates that O3 and possibly O2 of the backbone Xylp units are solvent-exposed. RESULTS 55 60 xylan chemical The capacity of CtXyl5A to act on the highly decorated xylan CX indicates that O3 and possibly O2 of the backbone Xylp units are solvent-exposed. RESULTS 61 63 CX chemical The capacity of CtXyl5A to act on the highly decorated xylan CX indicates that O3 and possibly O2 of the backbone Xylp units are solvent-exposed. RESULTS 114 118 Xylp chemical The capacity of CtXyl5A to act on the highly decorated xylan CX indicates that O3 and possibly O2 of the backbone Xylp units are solvent-exposed. RESULTS 129 144 solvent-exposed protein_state The capacity of CtXyl5A to act on the highly decorated xylan CX indicates that O3 and possibly O2 of the backbone Xylp units are solvent-exposed. RESULTS 47 59 xylotetraose chemical This is consistent with the interaction of the xylotetraose backbone with the enzyme distal to the active site. RESULTS 99 110 active site site This is consistent with the interaction of the xylotetraose backbone with the enzyme distal to the active site. RESULTS 73 79 xylose chemical A surface representation of the enzyme (Fig. 4B) shows that O3 and O2 of xylose units at subsites −2 to −4 are solvent-exposed and are thus available for decoration. RESULTS 89 106 subsites −2 to −4 site A surface representation of the enzyme (Fig. 4B) shows that O3 and O2 of xylose units at subsites −2 to −4 are solvent-exposed and are thus available for decoration. RESULTS 111 126 solvent-exposed protein_state A surface representation of the enzyme (Fig. 4B) shows that O3 and O2 of xylose units at subsites −2 to −4 are solvent-exposed and are thus available for decoration. RESULTS 14 22 pyranose chemical Indeed, these pyranose sugars make very weak apolar interactions with the arabinoxylanase. RESULTS 23 29 sugars chemical Indeed, these pyranose sugars make very weak apolar interactions with the arabinoxylanase. RESULTS 45 64 apolar interactions bond_interaction Indeed, these pyranose sugars make very weak apolar interactions with the arabinoxylanase. RESULTS 74 89 arabinoxylanase protein_type Indeed, these pyranose sugars make very weak apolar interactions with the arabinoxylanase. RESULTS 3 5 −2 site At −2, Xylp makes planar apolar interactions with the Araf bound to the −2* subsite (Fig. 4C). RESULTS 7 11 Xylp chemical At −2, Xylp makes planar apolar interactions with the Araf bound to the −2* subsite (Fig. 4C). RESULTS 18 44 planar apolar interactions bond_interaction At −2, Xylp makes planar apolar interactions with the Araf bound to the −2* subsite (Fig. 4C). RESULTS 54 58 Araf chemical At −2, Xylp makes planar apolar interactions with the Araf bound to the −2* subsite (Fig. 4C). RESULTS 59 67 bound to protein_state At −2, Xylp makes planar apolar interactions with the Araf bound to the −2* subsite (Fig. 4C). RESULTS 72 83 −2* subsite site At −2, Xylp makes planar apolar interactions with the Araf bound to the −2* subsite (Fig. 4C). RESULTS 0 4 Xylp chemical Xylp at subsites −2 and −3, respectively, make weak hydrophobic contact with Val318, the −3 Xylp makes planar apolar interactions with Ala137, whereas the xylose at −4 forms parallel apolar contacts with Trp69. RESULTS 8 26 subsites −2 and −3 site Xylp at subsites −2 and −3, respectively, make weak hydrophobic contact with Val318, the −3 Xylp makes planar apolar interactions with Ala137, whereas the xylose at −4 forms parallel apolar contacts with Trp69. RESULTS 52 71 hydrophobic contact bond_interaction Xylp at subsites −2 and −3, respectively, make weak hydrophobic contact with Val318, the −3 Xylp makes planar apolar interactions with Ala137, whereas the xylose at −4 forms parallel apolar contacts with Trp69. RESULTS 77 83 Val318 residue_name_number Xylp at subsites −2 and −3, respectively, make weak hydrophobic contact with Val318, the −3 Xylp makes planar apolar interactions with Ala137, whereas the xylose at −4 forms parallel apolar contacts with Trp69. RESULTS 89 91 −3 site Xylp at subsites −2 and −3, respectively, make weak hydrophobic contact with Val318, the −3 Xylp makes planar apolar interactions with Ala137, whereas the xylose at −4 forms parallel apolar contacts with Trp69. RESULTS 92 96 Xylp chemical Xylp at subsites −2 and −3, respectively, make weak hydrophobic contact with Val318, the −3 Xylp makes planar apolar interactions with Ala137, whereas the xylose at −4 forms parallel apolar contacts with Trp69. RESULTS 103 129 planar apolar interactions bond_interaction Xylp at subsites −2 and −3, respectively, make weak hydrophobic contact with Val318, the −3 Xylp makes planar apolar interactions with Ala137, whereas the xylose at −4 forms parallel apolar contacts with Trp69. RESULTS 135 141 Ala137 residue_name_number Xylp at subsites −2 and −3, respectively, make weak hydrophobic contact with Val318, the −3 Xylp makes planar apolar interactions with Ala137, whereas the xylose at −4 forms parallel apolar contacts with Trp69. RESULTS 155 161 xylose chemical Xylp at subsites −2 and −3, respectively, make weak hydrophobic contact with Val318, the −3 Xylp makes planar apolar interactions with Ala137, whereas the xylose at −4 forms parallel apolar contacts with Trp69. RESULTS 165 167 −4 site Xylp at subsites −2 and −3, respectively, make weak hydrophobic contact with Val318, the −3 Xylp makes planar apolar interactions with Ala137, whereas the xylose at −4 forms parallel apolar contacts with Trp69. RESULTS 174 198 parallel apolar contacts bond_interaction Xylp at subsites −2 and −3, respectively, make weak hydrophobic contact with Val318, the −3 Xylp makes planar apolar interactions with Ala137, whereas the xylose at −4 forms parallel apolar contacts with Trp69. RESULTS 204 209 Trp69 residue_name_number Xylp at subsites −2 and −3, respectively, make weak hydrophobic contact with Val318, the −3 Xylp makes planar apolar interactions with Ala137, whereas the xylose at −4 forms parallel apolar contacts with Trp69. RESULTS 25 42 negative subsites site Comparison of the distal negative subsites of CtXyl5A with BaCel5A and a typical GH10 xylanase (CmXyn10B, PDB code 1uqy) highlights the paucity of interactions between the arabinoxylanase and its substrate out with the active site (Fig. 4). RESULTS 46 53 CtXyl5A protein Comparison of the distal negative subsites of CtXyl5A with BaCel5A and a typical GH10 xylanase (CmXyn10B, PDB code 1uqy) highlights the paucity of interactions between the arabinoxylanase and its substrate out with the active site (Fig. 4). RESULTS 59 66 BaCel5A protein Comparison of the distal negative subsites of CtXyl5A with BaCel5A and a typical GH10 xylanase (CmXyn10B, PDB code 1uqy) highlights the paucity of interactions between the arabinoxylanase and its substrate out with the active site (Fig. 4). RESULTS 81 85 GH10 protein_type Comparison of the distal negative subsites of CtXyl5A with BaCel5A and a typical GH10 xylanase (CmXyn10B, PDB code 1uqy) highlights the paucity of interactions between the arabinoxylanase and its substrate out with the active site (Fig. 4). RESULTS 86 94 xylanase protein_type Comparison of the distal negative subsites of CtXyl5A with BaCel5A and a typical GH10 xylanase (CmXyn10B, PDB code 1uqy) highlights the paucity of interactions between the arabinoxylanase and its substrate out with the active site (Fig. 4). RESULTS 96 104 CmXyn10B protein Comparison of the distal negative subsites of CtXyl5A with BaCel5A and a typical GH10 xylanase (CmXyn10B, PDB code 1uqy) highlights the paucity of interactions between the arabinoxylanase and its substrate out with the active site (Fig. 4). RESULTS 172 187 arabinoxylanase protein_type Comparison of the distal negative subsites of CtXyl5A with BaCel5A and a typical GH10 xylanase (CmXyn10B, PDB code 1uqy) highlights the paucity of interactions between the arabinoxylanase and its substrate out with the active site (Fig. 4). RESULTS 219 230 active site site Comparison of the distal negative subsites of CtXyl5A with BaCel5A and a typical GH10 xylanase (CmXyn10B, PDB code 1uqy) highlights the paucity of interactions between the arabinoxylanase and its substrate out with the active site (Fig. 4). RESULTS 10 19 cellulase protein_type Thus, the cellulase contains three negative subsites and the sugars bound in the −2 and −3 subsites make a total of 9 polar interactions with the enzyme (Fig. 4, D and E). RESULTS 35 52 negative subsites site Thus, the cellulase contains three negative subsites and the sugars bound in the −2 and −3 subsites make a total of 9 polar interactions with the enzyme (Fig. 4, D and E). RESULTS 61 67 sugars chemical Thus, the cellulase contains three negative subsites and the sugars bound in the −2 and −3 subsites make a total of 9 polar interactions with the enzyme (Fig. 4, D and E). RESULTS 68 76 bound in protein_state Thus, the cellulase contains three negative subsites and the sugars bound in the −2 and −3 subsites make a total of 9 polar interactions with the enzyme (Fig. 4, D and E). RESULTS 81 99 −2 and −3 subsites site Thus, the cellulase contains three negative subsites and the sugars bound in the −2 and −3 subsites make a total of 9 polar interactions with the enzyme (Fig. 4, D and E). RESULTS 118 136 polar interactions bond_interaction Thus, the cellulase contains three negative subsites and the sugars bound in the −2 and −3 subsites make a total of 9 polar interactions with the enzyme (Fig. 4, D and E). RESULTS 4 8 GH10 protein_type The GH10 xylanase also contains a −2 subsite that, similar to the cellulase, makes numerous interactions with the substrate (Fig. 4, F and G). RESULTS 9 17 xylanase protein_type The GH10 xylanase also contains a −2 subsite that, similar to the cellulase, makes numerous interactions with the substrate (Fig. 4, F and G). RESULTS 34 44 −2 subsite site The GH10 xylanase also contains a −2 subsite that, similar to the cellulase, makes numerous interactions with the substrate (Fig. 4, F and G). RESULTS 66 75 cellulase protein_type The GH10 xylanase also contains a −2 subsite that, similar to the cellulase, makes numerous interactions with the substrate (Fig. 4, F and G). RESULTS 45 52 CtXyl5A protein The Influence of the Modular Architecture of CtXyl5A on Catalytic Activity RESULTS 0 7 CtXyl5A protein CtXyl5A, in addition to its catalytic module, contains three CBMs (CtCBM6, CtCBM13, and CtCBM62) and a fibronectin domain (CtFn3). RESULTS 28 44 catalytic module structure_element CtXyl5A, in addition to its catalytic module, contains three CBMs (CtCBM6, CtCBM13, and CtCBM62) and a fibronectin domain (CtFn3). RESULTS 61 65 CBMs structure_element CtXyl5A, in addition to its catalytic module, contains three CBMs (CtCBM6, CtCBM13, and CtCBM62) and a fibronectin domain (CtFn3). RESULTS 67 73 CtCBM6 structure_element CtXyl5A, in addition to its catalytic module, contains three CBMs (CtCBM6, CtCBM13, and CtCBM62) and a fibronectin domain (CtFn3). RESULTS 75 82 CtCBM13 structure_element CtXyl5A, in addition to its catalytic module, contains three CBMs (CtCBM6, CtCBM13, and CtCBM62) and a fibronectin domain (CtFn3). RESULTS 88 95 CtCBM62 structure_element CtXyl5A, in addition to its catalytic module, contains three CBMs (CtCBM6, CtCBM13, and CtCBM62) and a fibronectin domain (CtFn3). RESULTS 103 121 fibronectin domain structure_element CtXyl5A, in addition to its catalytic module, contains three CBMs (CtCBM6, CtCBM13, and CtCBM62) and a fibronectin domain (CtFn3). RESULTS 123 128 CtFn3 structure_element CtXyl5A, in addition to its catalytic module, contains three CBMs (CtCBM6, CtCBM13, and CtCBM62) and a fibronectin domain (CtFn3). RESULTS 42 46 CBM6 structure_element A previous study showed that although the CBM6 bound in an exo-mode to xylo- and cellulooligosaccharides, the primary role of this module was to stabilize the structure of the GH5 catalytic module. RESULTS 47 55 bound in protein_state A previous study showed that although the CBM6 bound in an exo-mode to xylo- and cellulooligosaccharides, the primary role of this module was to stabilize the structure of the GH5 catalytic module. RESULTS 59 67 exo-mode protein_state A previous study showed that although the CBM6 bound in an exo-mode to xylo- and cellulooligosaccharides, the primary role of this module was to stabilize the structure of the GH5 catalytic module. RESULTS 71 104 xylo- and cellulooligosaccharides chemical A previous study showed that although the CBM6 bound in an exo-mode to xylo- and cellulooligosaccharides, the primary role of this module was to stabilize the structure of the GH5 catalytic module. RESULTS 176 179 GH5 protein_type A previous study showed that although the CBM6 bound in an exo-mode to xylo- and cellulooligosaccharides, the primary role of this module was to stabilize the structure of the GH5 catalytic module. RESULTS 180 196 catalytic module structure_element A previous study showed that although the CBM6 bound in an exo-mode to xylo- and cellulooligosaccharides, the primary role of this module was to stabilize the structure of the GH5 catalytic module. RESULTS 41 62 non-catalytic modules structure_element To explore the contribution of the other non-catalytic modules to CtXyl5A function, the activity of a series of truncated derivatives of the arabinoxylanase were assessed. RESULTS 66 73 CtXyl5A protein To explore the contribution of the other non-catalytic modules to CtXyl5A function, the activity of a series of truncated derivatives of the arabinoxylanase were assessed. RESULTS 112 121 truncated protein_state To explore the contribution of the other non-catalytic modules to CtXyl5A function, the activity of a series of truncated derivatives of the arabinoxylanase were assessed. RESULTS 141 156 arabinoxylanase protein_type To explore the contribution of the other non-catalytic modules to CtXyl5A function, the activity of a series of truncated derivatives of the arabinoxylanase were assessed. RESULTS 30 40 removal of experimental_method The data in Table 1 show that removal of CtCBM62 caused a modest increase in activity against both WAX and CX, whereas deletion of the Fn3 domain had no further impact on catalytic performance. RESULTS 41 48 CtCBM62 structure_element The data in Table 1 show that removal of CtCBM62 caused a modest increase in activity against both WAX and CX, whereas deletion of the Fn3 domain had no further impact on catalytic performance. RESULTS 99 102 WAX chemical The data in Table 1 show that removal of CtCBM62 caused a modest increase in activity against both WAX and CX, whereas deletion of the Fn3 domain had no further impact on catalytic performance. RESULTS 107 109 CX chemical The data in Table 1 show that removal of CtCBM62 caused a modest increase in activity against both WAX and CX, whereas deletion of the Fn3 domain had no further impact on catalytic performance. RESULTS 119 130 deletion of experimental_method The data in Table 1 show that removal of CtCBM62 caused a modest increase in activity against both WAX and CX, whereas deletion of the Fn3 domain had no further impact on catalytic performance. RESULTS 135 138 Fn3 structure_element The data in Table 1 show that removal of CtCBM62 caused a modest increase in activity against both WAX and CX, whereas deletion of the Fn3 domain had no further impact on catalytic performance. RESULTS 0 10 Truncation experimental_method Truncation of CtCBM13, however, caused a 4–5-fold reduction in activity against both substrates. RESULTS 14 21 CtCBM13 structure_element Truncation of CtCBM13, however, caused a 4–5-fold reduction in activity against both substrates. RESULTS 11 16 CBM13 structure_element Members of CBM13 have been shown to bind to xylans, mannose, and galactose residues in complex glycans, hinting that the function of CtCBM13 is to increase the proximity of substrate to the catalytic module of CtXyl5A. RESULTS 44 50 xylans chemical Members of CBM13 have been shown to bind to xylans, mannose, and galactose residues in complex glycans, hinting that the function of CtCBM13 is to increase the proximity of substrate to the catalytic module of CtXyl5A. RESULTS 52 59 mannose chemical Members of CBM13 have been shown to bind to xylans, mannose, and galactose residues in complex glycans, hinting that the function of CtCBM13 is to increase the proximity of substrate to the catalytic module of CtXyl5A. RESULTS 65 74 galactose chemical Members of CBM13 have been shown to bind to xylans, mannose, and galactose residues in complex glycans, hinting that the function of CtCBM13 is to increase the proximity of substrate to the catalytic module of CtXyl5A. RESULTS 87 102 complex glycans chemical Members of CBM13 have been shown to bind to xylans, mannose, and galactose residues in complex glycans, hinting that the function of CtCBM13 is to increase the proximity of substrate to the catalytic module of CtXyl5A. RESULTS 133 140 CtCBM13 structure_element Members of CBM13 have been shown to bind to xylans, mannose, and galactose residues in complex glycans, hinting that the function of CtCBM13 is to increase the proximity of substrate to the catalytic module of CtXyl5A. RESULTS 190 206 catalytic module structure_element Members of CBM13 have been shown to bind to xylans, mannose, and galactose residues in complex glycans, hinting that the function of CtCBM13 is to increase the proximity of substrate to the catalytic module of CtXyl5A. RESULTS 210 217 CtXyl5A protein Members of CBM13 have been shown to bind to xylans, mannose, and galactose residues in complex glycans, hinting that the function of CtCBM13 is to increase the proximity of substrate to the catalytic module of CtXyl5A. RESULTS 0 15 Binding studies experimental_method Binding studies, however, showed that CtCBM13 displayed no affinity for a range of relevant glycans including WAX, CX, xylose, mannose, galactose, and birchwood xylan (BX) (data not shown). RESULTS 38 45 CtCBM13 structure_element Binding studies, however, showed that CtCBM13 displayed no affinity for a range of relevant glycans including WAX, CX, xylose, mannose, galactose, and birchwood xylan (BX) (data not shown). RESULTS 92 99 glycans chemical Binding studies, however, showed that CtCBM13 displayed no affinity for a range of relevant glycans including WAX, CX, xylose, mannose, galactose, and birchwood xylan (BX) (data not shown). RESULTS 110 113 WAX chemical Binding studies, however, showed that CtCBM13 displayed no affinity for a range of relevant glycans including WAX, CX, xylose, mannose, galactose, and birchwood xylan (BX) (data not shown). RESULTS 115 117 CX chemical Binding studies, however, showed that CtCBM13 displayed no affinity for a range of relevant glycans including WAX, CX, xylose, mannose, galactose, and birchwood xylan (BX) (data not shown). RESULTS 119 125 xylose chemical Binding studies, however, showed that CtCBM13 displayed no affinity for a range of relevant glycans including WAX, CX, xylose, mannose, galactose, and birchwood xylan (BX) (data not shown). RESULTS 127 134 mannose chemical Binding studies, however, showed that CtCBM13 displayed no affinity for a range of relevant glycans including WAX, CX, xylose, mannose, galactose, and birchwood xylan (BX) (data not shown). RESULTS 136 145 galactose chemical Binding studies, however, showed that CtCBM13 displayed no affinity for a range of relevant glycans including WAX, CX, xylose, mannose, galactose, and birchwood xylan (BX) (data not shown). RESULTS 151 166 birchwood xylan chemical Binding studies, however, showed that CtCBM13 displayed no affinity for a range of relevant glycans including WAX, CX, xylose, mannose, galactose, and birchwood xylan (BX) (data not shown). RESULTS 168 170 BX chemical Binding studies, however, showed that CtCBM13 displayed no affinity for a range of relevant glycans including WAX, CX, xylose, mannose, galactose, and birchwood xylan (BX) (data not shown). RESULTS 33 40 CtCBM13 structure_element It would appear, therefore, that CtCBM13 makes a structural contribution to the function of CtXyl5A. RESULTS 92 99 CtXyl5A protein It would appear, therefore, that CtCBM13 makes a structural contribution to the function of CtXyl5A. RESULTS 0 17 Crystal Structure evidence Crystal Structure of CtXyl5A-D RESULTS 21 30 CtXyl5A-D mutant Crystal Structure of CtXyl5A-D RESULTS 35 56 non-catalytic modules structure_element To explore further the role of the non-catalytic modules in CtXyl5A the crystal structure of CtXyl5A extending from CtGH5 to CtCBM62 was sought. RESULTS 60 67 CtXyl5A protein To explore further the role of the non-catalytic modules in CtXyl5A the crystal structure of CtXyl5A extending from CtGH5 to CtCBM62 was sought. RESULTS 72 89 crystal structure evidence To explore further the role of the non-catalytic modules in CtXyl5A the crystal structure of CtXyl5A extending from CtGH5 to CtCBM62 was sought. RESULTS 93 100 CtXyl5A protein To explore further the role of the non-catalytic modules in CtXyl5A the crystal structure of CtXyl5A extending from CtGH5 to CtCBM62 was sought. RESULTS 116 121 CtGH5 structure_element To explore further the role of the non-catalytic modules in CtXyl5A the crystal structure of CtXyl5A extending from CtGH5 to CtCBM62 was sought. RESULTS 125 132 CtCBM62 structure_element To explore further the role of the non-catalytic modules in CtXyl5A the crystal structure of CtXyl5A extending from CtGH5 to CtCBM62 was sought. RESULTS 48 60 crystallized experimental_method To obtain a construct that could potentially be crystallized, the protein was generated without the C-terminal dockerin domain because it is known to be unstable and prone to cleavage. RESULTS 88 95 without protein_state To obtain a construct that could potentially be crystallized, the protein was generated without the C-terminal dockerin domain because it is known to be unstable and prone to cleavage. RESULTS 111 119 dockerin structure_element To obtain a construct that could potentially be crystallized, the protein was generated without the C-terminal dockerin domain because it is known to be unstable and prone to cleavage. RESULTS 22 31 CtXyl5A-D mutant Using this construct (CtXyl5A-D) the crystal structure of the arabinoxylanase was determined by molecular replacement to a resolution of 2.64 Å with Rwork and Rfree at 23.7% and 27.8%, respectively. RESULTS 37 54 crystal structure evidence Using this construct (CtXyl5A-D) the crystal structure of the arabinoxylanase was determined by molecular replacement to a resolution of 2.64 Å with Rwork and Rfree at 23.7% and 27.8%, respectively. RESULTS 62 77 arabinoxylanase protein_type Using this construct (CtXyl5A-D) the crystal structure of the arabinoxylanase was determined by molecular replacement to a resolution of 2.64 Å with Rwork and Rfree at 23.7% and 27.8%, respectively. RESULTS 96 117 molecular replacement experimental_method Using this construct (CtXyl5A-D) the crystal structure of the arabinoxylanase was determined by molecular replacement to a resolution of 2.64 Å with Rwork and Rfree at 23.7% and 27.8%, respectively. RESULTS 149 154 Rwork evidence Using this construct (CtXyl5A-D) the crystal structure of the arabinoxylanase was determined by molecular replacement to a resolution of 2.64 Å with Rwork and Rfree at 23.7% and 27.8%, respectively. RESULTS 159 164 Rfree evidence Using this construct (CtXyl5A-D) the crystal structure of the arabinoxylanase was determined by molecular replacement to a resolution of 2.64 Å with Rwork and Rfree at 23.7% and 27.8%, respectively. RESULTS 4 13 structure evidence The structure comprises a continuous polypeptide extending from Ala36 to Trp742 displaying four modules GH5-CBM6-CBM13-Fn3. RESULTS 64 79 Ala36 to Trp742 residue_range The structure comprises a continuous polypeptide extending from Ala36 to Trp742 displaying four modules GH5-CBM6-CBM13-Fn3. RESULTS 104 122 GH5-CBM6-CBM13-Fn3 structure_element The structure comprises a continuous polypeptide extending from Ala36 to Trp742 displaying four modules GH5-CBM6-CBM13-Fn3. RESULTS 24 40 electron density evidence Although there was some electron density for CtCBM62, it was not sufficient to confidently build the module (Fig. 5). RESULTS 45 52 CtCBM62 structure_element Although there was some electron density for CtCBM62, it was not sufficient to confidently build the module (Fig. 5). RESULTS 29 44 crystal packing evidence Further investigation of the crystal packing revealed a large solvent channel adjacent to the area the CBM62 occupies. RESULTS 62 77 solvent channel site Further investigation of the crystal packing revealed a large solvent channel adjacent to the area the CBM62 occupies. RESULTS 103 108 CBM62 structure_element Further investigation of the crystal packing revealed a large solvent channel adjacent to the area the CBM62 occupies. RESULTS 42 58 electron density evidence We postulate that the reason for the poor electron density is due to the CtCBM62 being mobile compared with the rest of the protein. RESULTS 73 80 CtCBM62 structure_element We postulate that the reason for the poor electron density is due to the CtCBM62 being mobile compared with the rest of the protein. RESULTS 87 93 mobile protein_state We postulate that the reason for the poor electron density is due to the CtCBM62 being mobile compared with the rest of the protein. RESULTS 4 14 structures evidence The structures of CtGH5 and CtCBM6 have been described previously. RESULTS 18 23 CtGH5 structure_element The structures of CtGH5 and CtCBM6 have been described previously. RESULTS 28 34 CtCBM6 structure_element The structures of CtGH5 and CtCBM6 have been described previously. RESULTS 44 59 arabinoxylanase protein_type Surface representation of the tetra-modular arabinoxylanase and zoom view on the CtGH5 loop. FIG 81 86 CtGH5 structure_element Surface representation of the tetra-modular arabinoxylanase and zoom view on the CtGH5 loop. FIG 87 91 loop structure_element Surface representation of the tetra-modular arabinoxylanase and zoom view on the CtGH5 loop. FIG 23 28 CtGH5 structure_element The blue module is the CtGH5 catalytic domain, the green module corresponds to the CtCBM6, the yellow module is the CtCBM13, and the salmon module is the fibronectin domain. FIG 29 45 catalytic domain structure_element The blue module is the CtGH5 catalytic domain, the green module corresponds to the CtCBM6, the yellow module is the CtCBM13, and the salmon module is the fibronectin domain. FIG 83 89 CtCBM6 structure_element The blue module is the CtGH5 catalytic domain, the green module corresponds to the CtCBM6, the yellow module is the CtCBM13, and the salmon module is the fibronectin domain. FIG 116 123 CtCBM13 structure_element The blue module is the CtGH5 catalytic domain, the green module corresponds to the CtCBM6, the yellow module is the CtCBM13, and the salmon module is the fibronectin domain. FIG 154 172 fibronectin domain structure_element The blue module is the CtGH5 catalytic domain, the green module corresponds to the CtCBM6, the yellow module is the CtCBM13, and the salmon module is the fibronectin domain. FIG 4 9 CtGH5 structure_element The CtGH5 loop is stabilized between the CtCBM6 and the CtCBM13 modules. FIG 10 14 loop structure_element The CtGH5 loop is stabilized between the CtCBM6 and the CtCBM13 modules. FIG 41 47 CtCBM6 structure_element The CtGH5 loop is stabilized between the CtCBM6 and the CtCBM13 modules. FIG 56 63 CtCBM13 structure_element The CtGH5 loop is stabilized between the CtCBM6 and the CtCBM13 modules. FIG 0 7 CtCBM13 structure_element CtCBM13 extends from Gly567 to Pro648. RESULTS 21 37 Gly567 to Pro648 residue_range CtCBM13 extends from Gly567 to Pro648. RESULTS 11 16 CBM13 protein_type Typical of CBM13 proteins CtCBM13 displays a β-trefoil fold comprising the canonical pseudo 3-fold symmetry with a 3-fold repeating unit of 40–50 amino acid residues characteristic of the Ricin superfamily. RESULTS 26 33 CtCBM13 structure_element Typical of CBM13 proteins CtCBM13 displays a β-trefoil fold comprising the canonical pseudo 3-fold symmetry with a 3-fold repeating unit of 40–50 amino acid residues characteristic of the Ricin superfamily. RESULTS 45 59 β-trefoil fold structure_element Typical of CBM13 proteins CtCBM13 displays a β-trefoil fold comprising the canonical pseudo 3-fold symmetry with a 3-fold repeating unit of 40–50 amino acid residues characteristic of the Ricin superfamily. RESULTS 115 136 3-fold repeating unit structure_element Typical of CBM13 proteins CtCBM13 displays a β-trefoil fold comprising the canonical pseudo 3-fold symmetry with a 3-fold repeating unit of 40–50 amino acid residues characteristic of the Ricin superfamily. RESULTS 140 156 40–50 amino acid residue_range Typical of CBM13 proteins CtCBM13 displays a β-trefoil fold comprising the canonical pseudo 3-fold symmetry with a 3-fold repeating unit of 40–50 amino acid residues characteristic of the Ricin superfamily. RESULTS 188 205 Ricin superfamily protein_type Typical of CBM13 proteins CtCBM13 displays a β-trefoil fold comprising the canonical pseudo 3-fold symmetry with a 3-fold repeating unit of 40–50 amino acid residues characteristic of the Ricin superfamily. RESULTS 5 11 repeat structure_element Each repeat contains two pairs of antiparallel β-strands. RESULTS 34 56 antiparallel β-strands structure_element Each repeat contains two pairs of antiparallel β-strands. RESULTS 2 13 Dali search experimental_method A Dali search revealed structural homologs from the CBM13 family with an root mean square deviation less than 2.0 Å and sequence identities of less than 20% that include the functionally relevant homologs C. thermocellum exo-β-1,3-galactanase (PDB code 3vsz), Streptomyces avermitilis β-l-arabinopyranosidase (PDB code 3a21), Streptomyces lividans xylanase 10A (PDB code, 1mc9), and Streptomyces olivaceoviridis E-86 xylanase 10A (PDB code 1v6v). RESULTS 52 57 CBM13 protein_type A Dali search revealed structural homologs from the CBM13 family with an root mean square deviation less than 2.0 Å and sequence identities of less than 20% that include the functionally relevant homologs C. thermocellum exo-β-1,3-galactanase (PDB code 3vsz), Streptomyces avermitilis β-l-arabinopyranosidase (PDB code 3a21), Streptomyces lividans xylanase 10A (PDB code, 1mc9), and Streptomyces olivaceoviridis E-86 xylanase 10A (PDB code 1v6v). RESULTS 73 99 root mean square deviation evidence A Dali search revealed structural homologs from the CBM13 family with an root mean square deviation less than 2.0 Å and sequence identities of less than 20% that include the functionally relevant homologs C. thermocellum exo-β-1,3-galactanase (PDB code 3vsz), Streptomyces avermitilis β-l-arabinopyranosidase (PDB code 3a21), Streptomyces lividans xylanase 10A (PDB code, 1mc9), and Streptomyces olivaceoviridis E-86 xylanase 10A (PDB code 1v6v). RESULTS 205 220 C. thermocellum species A Dali search revealed structural homologs from the CBM13 family with an root mean square deviation less than 2.0 Å and sequence identities of less than 20% that include the functionally relevant homologs C. thermocellum exo-β-1,3-galactanase (PDB code 3vsz), Streptomyces avermitilis β-l-arabinopyranosidase (PDB code 3a21), Streptomyces lividans xylanase 10A (PDB code, 1mc9), and Streptomyces olivaceoviridis E-86 xylanase 10A (PDB code 1v6v). RESULTS 221 242 exo-β-1,3-galactanase protein_type A Dali search revealed structural homologs from the CBM13 family with an root mean square deviation less than 2.0 Å and sequence identities of less than 20% that include the functionally relevant homologs C. thermocellum exo-β-1,3-galactanase (PDB code 3vsz), Streptomyces avermitilis β-l-arabinopyranosidase (PDB code 3a21), Streptomyces lividans xylanase 10A (PDB code, 1mc9), and Streptomyces olivaceoviridis E-86 xylanase 10A (PDB code 1v6v). RESULTS 260 284 Streptomyces avermitilis species A Dali search revealed structural homologs from the CBM13 family with an root mean square deviation less than 2.0 Å and sequence identities of less than 20% that include the functionally relevant homologs C. thermocellum exo-β-1,3-galactanase (PDB code 3vsz), Streptomyces avermitilis β-l-arabinopyranosidase (PDB code 3a21), Streptomyces lividans xylanase 10A (PDB code, 1mc9), and Streptomyces olivaceoviridis E-86 xylanase 10A (PDB code 1v6v). RESULTS 285 308 β-l-arabinopyranosidase protein_type A Dali search revealed structural homologs from the CBM13 family with an root mean square deviation less than 2.0 Å and sequence identities of less than 20% that include the functionally relevant homologs C. thermocellum exo-β-1,3-galactanase (PDB code 3vsz), Streptomyces avermitilis β-l-arabinopyranosidase (PDB code 3a21), Streptomyces lividans xylanase 10A (PDB code, 1mc9), and Streptomyces olivaceoviridis E-86 xylanase 10A (PDB code 1v6v). RESULTS 326 347 Streptomyces lividans species A Dali search revealed structural homologs from the CBM13 family with an root mean square deviation less than 2.0 Å and sequence identities of less than 20% that include the functionally relevant homologs C. thermocellum exo-β-1,3-galactanase (PDB code 3vsz), Streptomyces avermitilis β-l-arabinopyranosidase (PDB code 3a21), Streptomyces lividans xylanase 10A (PDB code, 1mc9), and Streptomyces olivaceoviridis E-86 xylanase 10A (PDB code 1v6v). RESULTS 348 360 xylanase 10A protein A Dali search revealed structural homologs from the CBM13 family with an root mean square deviation less than 2.0 Å and sequence identities of less than 20% that include the functionally relevant homologs C. thermocellum exo-β-1,3-galactanase (PDB code 3vsz), Streptomyces avermitilis β-l-arabinopyranosidase (PDB code 3a21), Streptomyces lividans xylanase 10A (PDB code, 1mc9), and Streptomyces olivaceoviridis E-86 xylanase 10A (PDB code 1v6v). RESULTS 383 416 Streptomyces olivaceoviridis E-86 species A Dali search revealed structural homologs from the CBM13 family with an root mean square deviation less than 2.0 Å and sequence identities of less than 20% that include the functionally relevant homologs C. thermocellum exo-β-1,3-galactanase (PDB code 3vsz), Streptomyces avermitilis β-l-arabinopyranosidase (PDB code 3a21), Streptomyces lividans xylanase 10A (PDB code, 1mc9), and Streptomyces olivaceoviridis E-86 xylanase 10A (PDB code 1v6v). RESULTS 417 429 xylanase 10A protein A Dali search revealed structural homologs from the CBM13 family with an root mean square deviation less than 2.0 Å and sequence identities of less than 20% that include the functionally relevant homologs C. thermocellum exo-β-1,3-galactanase (PDB code 3vsz), Streptomyces avermitilis β-l-arabinopyranosidase (PDB code 3a21), Streptomyces lividans xylanase 10A (PDB code, 1mc9), and Streptomyces olivaceoviridis E-86 xylanase 10A (PDB code 1v6v). RESULTS 4 7 Fn3 structure_element The Fn3 module displays a typical β-sandwich fold with the two sheets comprising, primarily, three antiparallel strands in the order β1-β2-β5 in β-sheet 1 and β4-β3-β6 in β-sheet 2. RESULTS 34 49 β-sandwich fold structure_element The Fn3 module displays a typical β-sandwich fold with the two sheets comprising, primarily, three antiparallel strands in the order β1-β2-β5 in β-sheet 1 and β4-β3-β6 in β-sheet 2. RESULTS 63 69 sheets structure_element The Fn3 module displays a typical β-sandwich fold with the two sheets comprising, primarily, three antiparallel strands in the order β1-β2-β5 in β-sheet 1 and β4-β3-β6 in β-sheet 2. RESULTS 99 119 antiparallel strands structure_element The Fn3 module displays a typical β-sandwich fold with the two sheets comprising, primarily, three antiparallel strands in the order β1-β2-β5 in β-sheet 1 and β4-β3-β6 in β-sheet 2. RESULTS 133 141 β1-β2-β5 structure_element The Fn3 module displays a typical β-sandwich fold with the two sheets comprising, primarily, three antiparallel strands in the order β1-β2-β5 in β-sheet 1 and β4-β3-β6 in β-sheet 2. RESULTS 145 154 β-sheet 1 structure_element The Fn3 module displays a typical β-sandwich fold with the two sheets comprising, primarily, three antiparallel strands in the order β1-β2-β5 in β-sheet 1 and β4-β3-β6 in β-sheet 2. RESULTS 159 167 β4-β3-β6 structure_element The Fn3 module displays a typical β-sandwich fold with the two sheets comprising, primarily, three antiparallel strands in the order β1-β2-β5 in β-sheet 1 and β4-β3-β6 in β-sheet 2. RESULTS 171 180 β-sheet 2 structure_element The Fn3 module displays a typical β-sandwich fold with the two sheets comprising, primarily, three antiparallel strands in the order β1-β2-β5 in β-sheet 1 and β4-β3-β6 in β-sheet 2. RESULTS 9 18 β-sheet 2 structure_element Although β-sheet 2 presents a cleft-like topology, typical of endo-binding CBMs, the surface lacks aromatic residues that play a key role in ligand recognition, and in the context of the full-length enzyme, the cleft abuts into CtCBM13 and thus would not be able to accommodate an extended polysaccharide chain (see below). RESULTS 30 35 cleft site Although β-sheet 2 presents a cleft-like topology, typical of endo-binding CBMs, the surface lacks aromatic residues that play a key role in ligand recognition, and in the context of the full-length enzyme, the cleft abuts into CtCBM13 and thus would not be able to accommodate an extended polysaccharide chain (see below). RESULTS 62 79 endo-binding CBMs protein_type Although β-sheet 2 presents a cleft-like topology, typical of endo-binding CBMs, the surface lacks aromatic residues that play a key role in ligand recognition, and in the context of the full-length enzyme, the cleft abuts into CtCBM13 and thus would not be able to accommodate an extended polysaccharide chain (see below). RESULTS 187 198 full-length protein_state Although β-sheet 2 presents a cleft-like topology, typical of endo-binding CBMs, the surface lacks aromatic residues that play a key role in ligand recognition, and in the context of the full-length enzyme, the cleft abuts into CtCBM13 and thus would not be able to accommodate an extended polysaccharide chain (see below). RESULTS 199 205 enzyme protein Although β-sheet 2 presents a cleft-like topology, typical of endo-binding CBMs, the surface lacks aromatic residues that play a key role in ligand recognition, and in the context of the full-length enzyme, the cleft abuts into CtCBM13 and thus would not be able to accommodate an extended polysaccharide chain (see below). RESULTS 211 216 cleft site Although β-sheet 2 presents a cleft-like topology, typical of endo-binding CBMs, the surface lacks aromatic residues that play a key role in ligand recognition, and in the context of the full-length enzyme, the cleft abuts into CtCBM13 and thus would not be able to accommodate an extended polysaccharide chain (see below). RESULTS 228 235 CtCBM13 structure_element Although β-sheet 2 presents a cleft-like topology, typical of endo-binding CBMs, the surface lacks aromatic residues that play a key role in ligand recognition, and in the context of the full-length enzyme, the cleft abuts into CtCBM13 and thus would not be able to accommodate an extended polysaccharide chain (see below). RESULTS 290 304 polysaccharide chemical Although β-sheet 2 presents a cleft-like topology, typical of endo-binding CBMs, the surface lacks aromatic residues that play a key role in ligand recognition, and in the context of the full-length enzyme, the cleft abuts into CtCBM13 and thus would not be able to accommodate an extended polysaccharide chain (see below). RESULTS 7 16 structure evidence In the structure of CtXyl5A-D, the four modules form a three-leaf clover-like structure (Fig. 5). RESULTS 20 29 CtXyl5A-D mutant In the structure of CtXyl5A-D, the four modules form a three-leaf clover-like structure (Fig. 5). RESULTS 40 47 modules structure_element In the structure of CtXyl5A-D, the four modules form a three-leaf clover-like structure (Fig. 5). RESULTS 12 22 interfaces site Between the interfaces of CtGH5-CBM6-CBM13 there are a number of interactions that maintain the modules in a fixed position relative to each other. RESULTS 26 42 CtGH5-CBM6-CBM13 structure_element Between the interfaces of CtGH5-CBM6-CBM13 there are a number of interactions that maintain the modules in a fixed position relative to each other. RESULTS 19 24 CtGH5 structure_element The interaction of CtGH5 and CtCBM6, which buries a substantial apolar solvent-exposed surface of the two modules, has been described previously. RESULTS 29 35 CtCBM6 structure_element The interaction of CtGH5 and CtCBM6, which buries a substantial apolar solvent-exposed surface of the two modules, has been described previously. RESULTS 64 94 apolar solvent-exposed surface site The interaction of CtGH5 and CtCBM6, which buries a substantial apolar solvent-exposed surface of the two modules, has been described previously. RESULTS 4 22 polar interactions bond_interaction The polar interactions between these two modules comprise 14 hydrogen bonds and 5 salt bridges. RESULTS 61 75 hydrogen bonds bond_interaction The polar interactions between these two modules comprise 14 hydrogen bonds and 5 salt bridges. RESULTS 82 94 salt bridges bond_interaction The polar interactions between these two modules comprise 14 hydrogen bonds and 5 salt bridges. RESULTS 4 33 apolar and polar interactions bond_interaction The apolar and polar interactions between these two modules likely explaining why they do not fold independently compared with other glycoside hydrolases that contain CBMs. RESULTS 133 153 glycoside hydrolases protein_type The apolar and polar interactions between these two modules likely explaining why they do not fold independently compared with other glycoside hydrolases that contain CBMs. RESULTS 167 171 CBMs structure_element The apolar and polar interactions between these two modules likely explaining why they do not fold independently compared with other glycoside hydrolases that contain CBMs. RESULTS 0 7 CtCBM13 structure_element CtCBM13 acts as the central domain, which interacts with CtGH5, CtCBM6, and CtFn3 via 2, 5, and 4 hydrogen bonds, respectively, burying a surface area of ∼450, 350, and 500 Å2, respectively, to form a compact heterotetramer. RESULTS 20 34 central domain structure_element CtCBM13 acts as the central domain, which interacts with CtGH5, CtCBM6, and CtFn3 via 2, 5, and 4 hydrogen bonds, respectively, burying a surface area of ∼450, 350, and 500 Å2, respectively, to form a compact heterotetramer. RESULTS 42 56 interacts with protein_state CtCBM13 acts as the central domain, which interacts with CtGH5, CtCBM6, and CtFn3 via 2, 5, and 4 hydrogen bonds, respectively, burying a surface area of ∼450, 350, and 500 Å2, respectively, to form a compact heterotetramer. RESULTS 57 62 CtGH5 structure_element CtCBM13 acts as the central domain, which interacts with CtGH5, CtCBM6, and CtFn3 via 2, 5, and 4 hydrogen bonds, respectively, burying a surface area of ∼450, 350, and 500 Å2, respectively, to form a compact heterotetramer. RESULTS 64 70 CtCBM6 structure_element CtCBM13 acts as the central domain, which interacts with CtGH5, CtCBM6, and CtFn3 via 2, 5, and 4 hydrogen bonds, respectively, burying a surface area of ∼450, 350, and 500 Å2, respectively, to form a compact heterotetramer. RESULTS 76 81 CtFn3 structure_element CtCBM13 acts as the central domain, which interacts with CtGH5, CtCBM6, and CtFn3 via 2, 5, and 4 hydrogen bonds, respectively, burying a surface area of ∼450, 350, and 500 Å2, respectively, to form a compact heterotetramer. RESULTS 98 112 hydrogen bonds bond_interaction CtCBM13 acts as the central domain, which interacts with CtGH5, CtCBM6, and CtFn3 via 2, 5, and 4 hydrogen bonds, respectively, burying a surface area of ∼450, 350, and 500 Å2, respectively, to form a compact heterotetramer. RESULTS 201 208 compact protein_state CtCBM13 acts as the central domain, which interacts with CtGH5, CtCBM6, and CtFn3 via 2, 5, and 4 hydrogen bonds, respectively, burying a surface area of ∼450, 350, and 500 Å2, respectively, to form a compact heterotetramer. RESULTS 209 223 heterotetramer oligomeric_state CtCBM13 acts as the central domain, which interacts with CtGH5, CtCBM6, and CtFn3 via 2, 5, and 4 hydrogen bonds, respectively, burying a surface area of ∼450, 350, and 500 Å2, respectively, to form a compact heterotetramer. RESULTS 20 42 CtCBM6-CBM13 interface site With respect to the CtCBM6-CBM13 interface, the linker (SPISTGTIP) between the two modules, extending from Ser514 to Pro522, adopts a fixed conformation. RESULTS 48 54 linker structure_element With respect to the CtCBM6-CBM13 interface, the linker (SPISTGTIP) between the two modules, extending from Ser514 to Pro522, adopts a fixed conformation. RESULTS 56 65 SPISTGTIP structure_element With respect to the CtCBM6-CBM13 interface, the linker (SPISTGTIP) between the two modules, extending from Ser514 to Pro522, adopts a fixed conformation. RESULTS 83 90 modules structure_element With respect to the CtCBM6-CBM13 interface, the linker (SPISTGTIP) between the two modules, extending from Ser514 to Pro522, adopts a fixed conformation. RESULTS 107 113 Ser514 residue_name_number With respect to the CtCBM6-CBM13 interface, the linker (SPISTGTIP) between the two modules, extending from Ser514 to Pro522, adopts a fixed conformation. RESULTS 117 123 Pro522 residue_name_number With respect to the CtCBM6-CBM13 interface, the linker (SPISTGTIP) between the two modules, extending from Ser514 to Pro522, adopts a fixed conformation. RESULTS 134 152 fixed conformation protein_state With respect to the CtCBM6-CBM13 interface, the linker (SPISTGTIP) between the two modules, extending from Ser514 to Pro522, adopts a fixed conformation. RESULTS 65 68 Ile residue_name Such sequences are normally extremely flexible; however, the two Ile residues make extensive apolar contacts within the linker and with the two CBMs, leading to conformational stabilization. RESULTS 93 108 apolar contacts bond_interaction Such sequences are normally extremely flexible; however, the two Ile residues make extensive apolar contacts within the linker and with the two CBMs, leading to conformational stabilization. RESULTS 120 126 linker structure_element Such sequences are normally extremely flexible; however, the two Ile residues make extensive apolar contacts within the linker and with the two CBMs, leading to conformational stabilization. RESULTS 144 148 CBMs structure_element Such sequences are normally extremely flexible; however, the two Ile residues make extensive apolar contacts within the linker and with the two CBMs, leading to conformational stabilization. RESULTS 25 30 CtGH5 structure_element The interactions between CtGH5 and the two CBMs, which are mediated by the tip of the loop between β-7 and α-7 (loop 7) of CtGH5, not only stabilize the trimodular clover-like structure but also make a contribution to catalytic function. RESULTS 43 47 CBMs structure_element The interactions between CtGH5 and the two CBMs, which are mediated by the tip of the loop between β-7 and α-7 (loop 7) of CtGH5, not only stabilize the trimodular clover-like structure but also make a contribution to catalytic function. RESULTS 86 90 loop structure_element The interactions between CtGH5 and the two CBMs, which are mediated by the tip of the loop between β-7 and α-7 (loop 7) of CtGH5, not only stabilize the trimodular clover-like structure but also make a contribution to catalytic function. RESULTS 99 102 β-7 structure_element The interactions between CtGH5 and the two CBMs, which are mediated by the tip of the loop between β-7 and α-7 (loop 7) of CtGH5, not only stabilize the trimodular clover-like structure but also make a contribution to catalytic function. RESULTS 107 110 α-7 structure_element The interactions between CtGH5 and the two CBMs, which are mediated by the tip of the loop between β-7 and α-7 (loop 7) of CtGH5, not only stabilize the trimodular clover-like structure but also make a contribution to catalytic function. RESULTS 112 118 loop 7 structure_element The interactions between CtGH5 and the two CBMs, which are mediated by the tip of the loop between β-7 and α-7 (loop 7) of CtGH5, not only stabilize the trimodular clover-like structure but also make a contribution to catalytic function. RESULTS 123 128 CtGH5 structure_element The interactions between CtGH5 and the two CBMs, which are mediated by the tip of the loop between β-7 and α-7 (loop 7) of CtGH5, not only stabilize the trimodular clover-like structure but also make a contribution to catalytic function. RESULTS 153 170 trimodular clover structure_element The interactions between CtGH5 and the two CBMs, which are mediated by the tip of the loop between β-7 and α-7 (loop 7) of CtGH5, not only stabilize the trimodular clover-like structure but also make a contribution to catalytic function. RESULTS 46 53 modules structure_element Central to the interactions between the three modules is Trp285, which is intercalated between the two CBMs. RESULTS 57 63 Trp285 residue_name_number Central to the interactions between the three modules is Trp285, which is intercalated between the two CBMs. RESULTS 74 94 intercalated between bond_interaction Central to the interactions between the three modules is Trp285, which is intercalated between the two CBMs. RESULTS 103 107 CBMs structure_element Central to the interactions between the three modules is Trp285, which is intercalated between the two CBMs. RESULTS 38 52 hydrogen bonds bond_interaction The Nϵ of this aromatic residue makes hydrogen bonds with the backbone carbonyl of Val615 and Gly616 in CtCBM13, and the indole ring makes several apolar contacts with CtCBM6 (Pro440, Phe489, Gly491, and Ala492) (Fig. 5). RESULTS 83 89 Val615 residue_name_number The Nϵ of this aromatic residue makes hydrogen bonds with the backbone carbonyl of Val615 and Gly616 in CtCBM13, and the indole ring makes several apolar contacts with CtCBM6 (Pro440, Phe489, Gly491, and Ala492) (Fig. 5). RESULTS 94 100 Gly616 residue_name_number The Nϵ of this aromatic residue makes hydrogen bonds with the backbone carbonyl of Val615 and Gly616 in CtCBM13, and the indole ring makes several apolar contacts with CtCBM6 (Pro440, Phe489, Gly491, and Ala492) (Fig. 5). RESULTS 104 111 CtCBM13 structure_element The Nϵ of this aromatic residue makes hydrogen bonds with the backbone carbonyl of Val615 and Gly616 in CtCBM13, and the indole ring makes several apolar contacts with CtCBM6 (Pro440, Phe489, Gly491, and Ala492) (Fig. 5). RESULTS 147 162 apolar contacts bond_interaction The Nϵ of this aromatic residue makes hydrogen bonds with the backbone carbonyl of Val615 and Gly616 in CtCBM13, and the indole ring makes several apolar contacts with CtCBM6 (Pro440, Phe489, Gly491, and Ala492) (Fig. 5). RESULTS 168 174 CtCBM6 structure_element The Nϵ of this aromatic residue makes hydrogen bonds with the backbone carbonyl of Val615 and Gly616 in CtCBM13, and the indole ring makes several apolar contacts with CtCBM6 (Pro440, Phe489, Gly491, and Ala492) (Fig. 5). RESULTS 176 182 Pro440 residue_name_number The Nϵ of this aromatic residue makes hydrogen bonds with the backbone carbonyl of Val615 and Gly616 in CtCBM13, and the indole ring makes several apolar contacts with CtCBM6 (Pro440, Phe489, Gly491, and Ala492) (Fig. 5). RESULTS 184 190 Phe489 residue_name_number The Nϵ of this aromatic residue makes hydrogen bonds with the backbone carbonyl of Val615 and Gly616 in CtCBM13, and the indole ring makes several apolar contacts with CtCBM6 (Pro440, Phe489, Gly491, and Ala492) (Fig. 5). RESULTS 192 198 Gly491 residue_name_number The Nϵ of this aromatic residue makes hydrogen bonds with the backbone carbonyl of Val615 and Gly616 in CtCBM13, and the indole ring makes several apolar contacts with CtCBM6 (Pro440, Phe489, Gly491, and Ala492) (Fig. 5). RESULTS 204 210 Ala492 residue_name_number The Nϵ of this aromatic residue makes hydrogen bonds with the backbone carbonyl of Val615 and Gly616 in CtCBM13, and the indole ring makes several apolar contacts with CtCBM6 (Pro440, Phe489, Gly491, and Ala492) (Fig. 5). RESULTS 8 14 loop 7 structure_element Indeed, loop 7 is completely disordered in the truncated derivative of CtXyl5A comprising CtGH5 and CtCBM6, demonstrating that the interactions with CtCBM13 stabilize the conformation of this loop. RESULTS 18 39 completely disordered protein_state Indeed, loop 7 is completely disordered in the truncated derivative of CtXyl5A comprising CtGH5 and CtCBM6, demonstrating that the interactions with CtCBM13 stabilize the conformation of this loop. RESULTS 47 56 truncated protein_state Indeed, loop 7 is completely disordered in the truncated derivative of CtXyl5A comprising CtGH5 and CtCBM6, demonstrating that the interactions with CtCBM13 stabilize the conformation of this loop. RESULTS 71 78 CtXyl5A protein Indeed, loop 7 is completely disordered in the truncated derivative of CtXyl5A comprising CtGH5 and CtCBM6, demonstrating that the interactions with CtCBM13 stabilize the conformation of this loop. RESULTS 90 95 CtGH5 structure_element Indeed, loop 7 is completely disordered in the truncated derivative of CtXyl5A comprising CtGH5 and CtCBM6, demonstrating that the interactions with CtCBM13 stabilize the conformation of this loop. RESULTS 100 106 CtCBM6 structure_element Indeed, loop 7 is completely disordered in the truncated derivative of CtXyl5A comprising CtGH5 and CtCBM6, demonstrating that the interactions with CtCBM13 stabilize the conformation of this loop. RESULTS 149 156 CtCBM13 structure_element Indeed, loop 7 is completely disordered in the truncated derivative of CtXyl5A comprising CtGH5 and CtCBM6, demonstrating that the interactions with CtCBM13 stabilize the conformation of this loop. RESULTS 192 196 loop structure_element Indeed, loop 7 is completely disordered in the truncated derivative of CtXyl5A comprising CtGH5 and CtCBM6, demonstrating that the interactions with CtCBM13 stabilize the conformation of this loop. RESULTS 20 26 loop 7 structure_element Although the tip of loop 7 does not directly contribute to the topology of the active site, it is only ∼12 Å from the catalytic nucleophile Glu279. RESULTS 79 90 active site site Although the tip of loop 7 does not directly contribute to the topology of the active site, it is only ∼12 Å from the catalytic nucleophile Glu279. RESULTS 140 146 Glu279 residue_name_number Although the tip of loop 7 does not directly contribute to the topology of the active site, it is only ∼12 Å from the catalytic nucleophile Glu279. RESULTS 30 34 loop structure_element Thus, any perturbation of the loop (through the removal of CtCBM13) is likely to influence the electrostatic and apolar environment of the catalytic apparatus, which could explain the reduction in activity associated with the deletion of CtCBM13. RESULTS 48 55 removal experimental_method Thus, any perturbation of the loop (through the removal of CtCBM13) is likely to influence the electrostatic and apolar environment of the catalytic apparatus, which could explain the reduction in activity associated with the deletion of CtCBM13. RESULTS 59 66 CtCBM13 structure_element Thus, any perturbation of the loop (through the removal of CtCBM13) is likely to influence the electrostatic and apolar environment of the catalytic apparatus, which could explain the reduction in activity associated with the deletion of CtCBM13. RESULTS 226 234 deletion experimental_method Thus, any perturbation of the loop (through the removal of CtCBM13) is likely to influence the electrostatic and apolar environment of the catalytic apparatus, which could explain the reduction in activity associated with the deletion of CtCBM13. RESULTS 238 245 CtCBM13 structure_element Thus, any perturbation of the loop (through the removal of CtCBM13) is likely to influence the electrostatic and apolar environment of the catalytic apparatus, which could explain the reduction in activity associated with the deletion of CtCBM13. RESULTS 36 42 CtCBM6 structure_element Similar to the interactions between CtCBM6 and CtCBM13, there are extensive hydrophobic interactions between CtCBM13 and CtFn3, resulting in very little flexibility between these modules. RESULTS 47 54 CtCBM13 structure_element Similar to the interactions between CtCBM6 and CtCBM13, there are extensive hydrophobic interactions between CtCBM13 and CtFn3, resulting in very little flexibility between these modules. RESULTS 76 100 hydrophobic interactions bond_interaction Similar to the interactions between CtCBM6 and CtCBM13, there are extensive hydrophobic interactions between CtCBM13 and CtFn3, resulting in very little flexibility between these modules. RESULTS 109 116 CtCBM13 structure_element Similar to the interactions between CtCBM6 and CtCBM13, there are extensive hydrophobic interactions between CtCBM13 and CtFn3, resulting in very little flexibility between these modules. RESULTS 121 126 CtFn3 structure_element Similar to the interactions between CtCBM6 and CtCBM13, there are extensive hydrophobic interactions between CtCBM13 and CtFn3, resulting in very little flexibility between these modules. RESULTS 179 186 modules structure_element Similar to the interactions between CtCBM6 and CtCBM13, there are extensive hydrophobic interactions between CtCBM13 and CtFn3, resulting in very little flexibility between these modules. RESULTS 21 31 absence of protein_state As stated above, the absence of CtCBM62 in the structure suggests that the module can adopt multiple positions with respect to the rest of the protein. RESULTS 32 39 CtCBM62 structure_element As stated above, the absence of CtCBM62 in the structure suggests that the module can adopt multiple positions with respect to the rest of the protein. RESULTS 47 56 structure evidence As stated above, the absence of CtCBM62 in the structure suggests that the module can adopt multiple positions with respect to the rest of the protein. RESULTS 75 81 module structure_element As stated above, the absence of CtCBM62 in the structure suggests that the module can adopt multiple positions with respect to the rest of the protein. RESULTS 4 11 CtCBM62 structure_element The CtCBM62, by binding to its ligands (d-Galp and l-Arap) in plant cell walls, may be able to recruit the enzyme onto its target substrate. RESULTS 16 26 binding to protein_state The CtCBM62, by binding to its ligands (d-Galp and l-Arap) in plant cell walls, may be able to recruit the enzyme onto its target substrate. RESULTS 40 46 d-Galp chemical The CtCBM62, by binding to its ligands (d-Galp and l-Arap) in plant cell walls, may be able to recruit the enzyme onto its target substrate. RESULTS 51 57 l-Arap chemical The CtCBM62, by binding to its ligands (d-Galp and l-Arap) in plant cell walls, may be able to recruit the enzyme onto its target substrate. RESULTS 62 67 plant taxonomy_domain The CtCBM62, by binding to its ligands (d-Galp and l-Arap) in plant cell walls, may be able to recruit the enzyme onto its target substrate. RESULTS 0 6 Xylans chemical Xylans are not generally thought to contain such sugars. RESULTS 49 55 sugars chemical Xylans are not generally thought to contain such sugars. RESULTS 0 6 d-Galp chemical d-Galp, however, has been detected in xylans in the outer layer of cereal grains and in eucalyptus trees, which are substrates used by CtXyl5A. RESULTS 38 44 xylans chemical d-Galp, however, has been detected in xylans in the outer layer of cereal grains and in eucalyptus trees, which are substrates used by CtXyl5A. RESULTS 67 73 cereal taxonomy_domain d-Galp, however, has been detected in xylans in the outer layer of cereal grains and in eucalyptus trees, which are substrates used by CtXyl5A. RESULTS 88 104 eucalyptus trees taxonomy_domain d-Galp, however, has been detected in xylans in the outer layer of cereal grains and in eucalyptus trees, which are substrates used by CtXyl5A. RESULTS 135 142 CtXyl5A protein d-Galp, however, has been detected in xylans in the outer layer of cereal grains and in eucalyptus trees, which are substrates used by CtXyl5A. RESULTS 6 13 CtCBM62 structure_element Thus, CtCBM62 may direct the enzyme to particularly complex xylans containing d-Galp at the non-reducing termini of the side chains, consistent with the open substrate binding cleft of the arabinoxylanase that is optimized to bind highly decorated forms of the hemicellulose. RESULTS 60 66 xylans chemical Thus, CtCBM62 may direct the enzyme to particularly complex xylans containing d-Galp at the non-reducing termini of the side chains, consistent with the open substrate binding cleft of the arabinoxylanase that is optimized to bind highly decorated forms of the hemicellulose. RESULTS 78 84 d-Galp chemical Thus, CtCBM62 may direct the enzyme to particularly complex xylans containing d-Galp at the non-reducing termini of the side chains, consistent with the open substrate binding cleft of the arabinoxylanase that is optimized to bind highly decorated forms of the hemicellulose. RESULTS 153 157 open protein_state Thus, CtCBM62 may direct the enzyme to particularly complex xylans containing d-Galp at the non-reducing termini of the side chains, consistent with the open substrate binding cleft of the arabinoxylanase that is optimized to bind highly decorated forms of the hemicellulose. RESULTS 158 181 substrate binding cleft site Thus, CtCBM62 may direct the enzyme to particularly complex xylans containing d-Galp at the non-reducing termini of the side chains, consistent with the open substrate binding cleft of the arabinoxylanase that is optimized to bind highly decorated forms of the hemicellulose. RESULTS 189 204 arabinoxylanase protein_type Thus, CtCBM62 may direct the enzyme to particularly complex xylans containing d-Galp at the non-reducing termini of the side chains, consistent with the open substrate binding cleft of the arabinoxylanase that is optimized to bind highly decorated forms of the hemicellulose. RESULTS 261 274 hemicellulose chemical Thus, CtCBM62 may direct the enzyme to particularly complex xylans containing d-Galp at the non-reducing termini of the side chains, consistent with the open substrate binding cleft of the arabinoxylanase that is optimized to bind highly decorated forms of the hemicellulose. RESULTS 11 15 CBMs structure_element In general CBMs have little influence on enzyme activity against soluble substrates but have a significant impact on glycans within plant cell walls. RESULTS 117 124 glycans chemical In general CBMs have little influence on enzyme activity against soluble substrates but have a significant impact on glycans within plant cell walls. RESULTS 132 137 plant taxonomy_domain In general CBMs have little influence on enzyme activity against soluble substrates but have a significant impact on glycans within plant cell walls. RESULTS 18 23 CBM62 structure_element Thus, the role of CBM62 will likely only be evident against insoluble composite substrates. RESULTS 10 26 GH5 Subfamily 34 protein_type Exploring GH5 Subfamily 34 RESULTS 0 7 CtXyl5A protein CtXyl5A is a member of a seven-protein subfamily of GH5, GH5_34. RESULTS 52 55 GH5 protein_type CtXyl5A is a member of a seven-protein subfamily of GH5, GH5_34. RESULTS 57 63 GH5_34 protein_type CtXyl5A is a member of a seven-protein subfamily of GH5, GH5_34. RESULTS 130 145 C. thermocellum species Four of these proteins are distinct, whereas the other three members are essentially identical (derived from different strains of C. thermocellum). RESULTS 110 116 GH5_34 protein_type To investigate further the substrate specificity within this subfamily, recombinant forms of three members of GH5_34 that were distinct from CtXyl5A were generated. RESULTS 141 148 CtXyl5A protein To investigate further the substrate specificity within this subfamily, recombinant forms of three members of GH5_34 that were distinct from CtXyl5A were generated. RESULTS 0 5 AcGH5 protein AcGH5 has a similar molecular architecture to CtXyl5A with the exception of an additional carbohydrate esterase family 6 module at the C terminus (Fig. 1). RESULTS 46 53 CtXyl5A protein AcGH5 has a similar molecular architecture to CtXyl5A with the exception of an additional carbohydrate esterase family 6 module at the C terminus (Fig. 1). RESULTS 90 127 carbohydrate esterase family 6 module structure_element AcGH5 has a similar molecular architecture to CtXyl5A with the exception of an additional carbohydrate esterase family 6 module at the C terminus (Fig. 1). RESULTS 4 10 GH5_34 protein_type The GH5_34 from Verrucomicrobiae bacterium, VbGH5, contains the GH5-CBM6-CBM13 core structure, but the C-terminal Fn3-CBM62-dockerin modules, present in CtXyl5A, are replaced with a Laminin_3_G domain, which, by analogy to homologous domains in other proteins that have affinity for carbohydrates, may display a glycan binding function. RESULTS 16 32 Verrucomicrobiae taxonomy_domain The GH5_34 from Verrucomicrobiae bacterium, VbGH5, contains the GH5-CBM6-CBM13 core structure, but the C-terminal Fn3-CBM62-dockerin modules, present in CtXyl5A, are replaced with a Laminin_3_G domain, which, by analogy to homologous domains in other proteins that have affinity for carbohydrates, may display a glycan binding function. RESULTS 33 42 bacterium taxonomy_domain The GH5_34 from Verrucomicrobiae bacterium, VbGH5, contains the GH5-CBM6-CBM13 core structure, but the C-terminal Fn3-CBM62-dockerin modules, present in CtXyl5A, are replaced with a Laminin_3_G domain, which, by analogy to homologous domains in other proteins that have affinity for carbohydrates, may display a glycan binding function. RESULTS 44 49 VbGH5 protein The GH5_34 from Verrucomicrobiae bacterium, VbGH5, contains the GH5-CBM6-CBM13 core structure, but the C-terminal Fn3-CBM62-dockerin modules, present in CtXyl5A, are replaced with a Laminin_3_G domain, which, by analogy to homologous domains in other proteins that have affinity for carbohydrates, may display a glycan binding function. RESULTS 64 78 GH5-CBM6-CBM13 structure_element The GH5_34 from Verrucomicrobiae bacterium, VbGH5, contains the GH5-CBM6-CBM13 core structure, but the C-terminal Fn3-CBM62-dockerin modules, present in CtXyl5A, are replaced with a Laminin_3_G domain, which, by analogy to homologous domains in other proteins that have affinity for carbohydrates, may display a glycan binding function. RESULTS 114 132 Fn3-CBM62-dockerin structure_element The GH5_34 from Verrucomicrobiae bacterium, VbGH5, contains the GH5-CBM6-CBM13 core structure, but the C-terminal Fn3-CBM62-dockerin modules, present in CtXyl5A, are replaced with a Laminin_3_G domain, which, by analogy to homologous domains in other proteins that have affinity for carbohydrates, may display a glycan binding function. RESULTS 153 160 CtXyl5A protein The GH5_34 from Verrucomicrobiae bacterium, VbGH5, contains the GH5-CBM6-CBM13 core structure, but the C-terminal Fn3-CBM62-dockerin modules, present in CtXyl5A, are replaced with a Laminin_3_G domain, which, by analogy to homologous domains in other proteins that have affinity for carbohydrates, may display a glycan binding function. RESULTS 182 200 Laminin_3_G domain structure_element The GH5_34 from Verrucomicrobiae bacterium, VbGH5, contains the GH5-CBM6-CBM13 core structure, but the C-terminal Fn3-CBM62-dockerin modules, present in CtXyl5A, are replaced with a Laminin_3_G domain, which, by analogy to homologous domains in other proteins that have affinity for carbohydrates, may display a glycan binding function. RESULTS 283 296 carbohydrates chemical The GH5_34 from Verrucomicrobiae bacterium, VbGH5, contains the GH5-CBM6-CBM13 core structure, but the C-terminal Fn3-CBM62-dockerin modules, present in CtXyl5A, are replaced with a Laminin_3_G domain, which, by analogy to homologous domains in other proteins that have affinity for carbohydrates, may display a glycan binding function. RESULTS 312 318 glycan chemical The GH5_34 from Verrucomicrobiae bacterium, VbGH5, contains the GH5-CBM6-CBM13 core structure, but the C-terminal Fn3-CBM62-dockerin modules, present in CtXyl5A, are replaced with a Laminin_3_G domain, which, by analogy to homologous domains in other proteins that have affinity for carbohydrates, may display a glycan binding function. RESULTS 4 19 Verrucomicobiae taxonomy_domain The Verrucomicobiae enzyme also has an N-terminal GH43 subfamily 10 (GH43_10) catalytic module. RESULTS 50 67 GH43 subfamily 10 protein_type The Verrucomicobiae enzyme also has an N-terminal GH43 subfamily 10 (GH43_10) catalytic module. RESULTS 69 76 GH43_10 protein_type The Verrucomicobiae enzyme also has an N-terminal GH43 subfamily 10 (GH43_10) catalytic module. RESULTS 78 94 catalytic module structure_element The Verrucomicobiae enzyme also has an N-terminal GH43 subfamily 10 (GH43_10) catalytic module. RESULTS 4 10 fungal taxonomy_domain The fungal GH5_34, GpGH5, unlike the two bacterial homologs, comprises a single GH5 catalytic module lacking all of the other accessory modules (Fig. 1). RESULTS 11 17 GH5_34 protein_type The fungal GH5_34, GpGH5, unlike the two bacterial homologs, comprises a single GH5 catalytic module lacking all of the other accessory modules (Fig. 1). RESULTS 19 24 GpGH5 protein The fungal GH5_34, GpGH5, unlike the two bacterial homologs, comprises a single GH5 catalytic module lacking all of the other accessory modules (Fig. 1). RESULTS 41 50 bacterial taxonomy_domain The fungal GH5_34, GpGH5, unlike the two bacterial homologs, comprises a single GH5 catalytic module lacking all of the other accessory modules (Fig. 1). RESULTS 80 83 GH5 protein_type The fungal GH5_34, GpGH5, unlike the two bacterial homologs, comprises a single GH5 catalytic module lacking all of the other accessory modules (Fig. 1). RESULTS 84 100 catalytic module structure_element The fungal GH5_34, GpGH5, unlike the two bacterial homologs, comprises a single GH5 catalytic module lacking all of the other accessory modules (Fig. 1). RESULTS 0 5 GpGh5 protein GpGh5 is particularly interesting as Gonapodya prolifera is the only fungus of the several hundred fungal genomes that encodes a GH5_34 enzyme. RESULTS 37 56 Gonapodya prolifera species GpGh5 is particularly interesting as Gonapodya prolifera is the only fungus of the several hundred fungal genomes that encodes a GH5_34 enzyme. RESULTS 69 75 fungus taxonomy_domain GpGh5 is particularly interesting as Gonapodya prolifera is the only fungus of the several hundred fungal genomes that encodes a GH5_34 enzyme. RESULTS 99 105 fungal taxonomy_domain GpGh5 is particularly interesting as Gonapodya prolifera is the only fungus of the several hundred fungal genomes that encodes a GH5_34 enzyme. RESULTS 129 135 GH5_34 protein_type GpGh5 is particularly interesting as Gonapodya prolifera is the only fungus of the several hundred fungal genomes that encodes a GH5_34 enzyme. RESULTS 33 39 GH5_34 protein_type In fact there are four potential GH5_34 sequences in the G. prolifera genome, all of which show high sequence homology to Clostridium GH5_34 sequences. RESULTS 57 69 G. prolifera species In fact there are four potential GH5_34 sequences in the G. prolifera genome, all of which show high sequence homology to Clostridium GH5_34 sequences. RESULTS 122 133 Clostridium taxonomy_domain In fact there are four potential GH5_34 sequences in the G. prolifera genome, all of which show high sequence homology to Clostridium GH5_34 sequences. RESULTS 134 140 GH5_34 protein_type In fact there are four potential GH5_34 sequences in the G. prolifera genome, all of which show high sequence homology to Clostridium GH5_34 sequences. RESULTS 0 12 G. prolifera species G. prolifera and Clostridium occupy similar environments, suggesting that the GpGH5_34 gene was acquired from a Clostridium species, which was followed by duplication of the gene in the fungal genome. RESULTS 17 28 Clostridium taxonomy_domain G. prolifera and Clostridium occupy similar environments, suggesting that the GpGH5_34 gene was acquired from a Clostridium species, which was followed by duplication of the gene in the fungal genome. RESULTS 78 86 GpGH5_34 protein G. prolifera and Clostridium occupy similar environments, suggesting that the GpGH5_34 gene was acquired from a Clostridium species, which was followed by duplication of the gene in the fungal genome. RESULTS 112 123 Clostridium taxonomy_domain G. prolifera and Clostridium occupy similar environments, suggesting that the GpGH5_34 gene was acquired from a Clostridium species, which was followed by duplication of the gene in the fungal genome. RESULTS 186 192 fungal taxonomy_domain G. prolifera and Clostridium occupy similar environments, suggesting that the GpGH5_34 gene was acquired from a Clostridium species, which was followed by duplication of the gene in the fungal genome. RESULTS 29 35 GH5_34 protein_type The sequence identity of the GH5_34 catalytic modules with CtXyl5A ranged from 55 to 80% (supplemental Fig. S1). RESULTS 36 53 catalytic modules structure_element The sequence identity of the GH5_34 catalytic modules with CtXyl5A ranged from 55 to 80% (supplemental Fig. S1). RESULTS 59 66 CtXyl5A protein The sequence identity of the GH5_34 catalytic modules with CtXyl5A ranged from 55 to 80% (supplemental Fig. S1). RESULTS 8 14 GH5_34 protein_type All the GH5_34 enzymes were active on the arabinoxylans RAX, WAX, and CX but displayed no activity on BX (Table 1 and Fig. 6) and are thus defined as arabinoxylanases. RESULTS 42 55 arabinoxylans chemical All the GH5_34 enzymes were active on the arabinoxylans RAX, WAX, and CX but displayed no activity on BX (Table 1 and Fig. 6) and are thus defined as arabinoxylanases. RESULTS 56 59 RAX chemical All the GH5_34 enzymes were active on the arabinoxylans RAX, WAX, and CX but displayed no activity on BX (Table 1 and Fig. 6) and are thus defined as arabinoxylanases. RESULTS 61 64 WAX chemical All the GH5_34 enzymes were active on the arabinoxylans RAX, WAX, and CX but displayed no activity on BX (Table 1 and Fig. 6) and are thus defined as arabinoxylanases. RESULTS 70 72 CX chemical All the GH5_34 enzymes were active on the arabinoxylans RAX, WAX, and CX but displayed no activity on BX (Table 1 and Fig. 6) and are thus defined as arabinoxylanases. RESULTS 102 104 BX chemical All the GH5_34 enzymes were active on the arabinoxylans RAX, WAX, and CX but displayed no activity on BX (Table 1 and Fig. 6) and are thus defined as arabinoxylanases. RESULTS 150 166 arabinoxylanases protein_type All the GH5_34 enzymes were active on the arabinoxylans RAX, WAX, and CX but displayed no activity on BX (Table 1 and Fig. 6) and are thus defined as arabinoxylanases. RESULTS 32 39 CtXyl5A protein The limit products generated by CtXyl5A, AcGH5, and GpGH5 comprised a range of oligosaccharides with some high molecular weight material. RESULTS 41 46 AcGH5 protein The limit products generated by CtXyl5A, AcGH5, and GpGH5 comprised a range of oligosaccharides with some high molecular weight material. RESULTS 52 57 GpGH5 protein The limit products generated by CtXyl5A, AcGH5, and GpGH5 comprised a range of oligosaccharides with some high molecular weight material. RESULTS 79 95 oligosaccharides chemical The limit products generated by CtXyl5A, AcGH5, and GpGH5 comprised a range of oligosaccharides with some high molecular weight material. RESULTS 4 20 oligosaccharides chemical The oligosaccharides with low degrees of polymerization were absent in the VbGH5 reaction products. RESULTS 75 80 VbGH5 protein The oligosaccharides with low degrees of polymerization were absent in the VbGH5 reaction products. RESULTS 48 57 arabinose chemical However, the enzyme generated a large amount of arabinose, which was not produced by the other arabinoxylanases. RESULTS 95 111 arabinoxylanases protein_type However, the enzyme generated a large amount of arabinose, which was not produced by the other arabinoxylanases. RESULTS 11 18 GH43_10 protein_type Given that GH43_10 is predominantly an arabinofuranosidase subfamily of GH43, the arabinose generated by VbGH5 is likely mediated by the N-terminal catalytic module (see below). RESULTS 39 58 arabinofuranosidase protein_type Given that GH43_10 is predominantly an arabinofuranosidase subfamily of GH43, the arabinose generated by VbGH5 is likely mediated by the N-terminal catalytic module (see below). RESULTS 72 76 GH43 protein_type Given that GH43_10 is predominantly an arabinofuranosidase subfamily of GH43, the arabinose generated by VbGH5 is likely mediated by the N-terminal catalytic module (see below). RESULTS 82 91 arabinose chemical Given that GH43_10 is predominantly an arabinofuranosidase subfamily of GH43, the arabinose generated by VbGH5 is likely mediated by the N-terminal catalytic module (see below). RESULTS 105 110 VbGH5 protein Given that GH43_10 is predominantly an arabinofuranosidase subfamily of GH43, the arabinose generated by VbGH5 is likely mediated by the N-terminal catalytic module (see below). RESULTS 148 164 catalytic module structure_element Given that GH43_10 is predominantly an arabinofuranosidase subfamily of GH43, the arabinose generated by VbGH5 is likely mediated by the N-terminal catalytic module (see below). RESULTS 29 34 AcGH5 protein Kinetic analysis showed that AcGH5 displayed similar activity to CtXyl5A against both WAX and RAX and was 2-fold less active against CX. RESULTS 65 72 CtXyl5A protein Kinetic analysis showed that AcGH5 displayed similar activity to CtXyl5A against both WAX and RAX and was 2-fold less active against CX. RESULTS 86 89 WAX chemical Kinetic analysis showed that AcGH5 displayed similar activity to CtXyl5A against both WAX and RAX and was 2-fold less active against CX. RESULTS 94 97 RAX chemical Kinetic analysis showed that AcGH5 displayed similar activity to CtXyl5A against both WAX and RAX and was 2-fold less active against CX. RESULTS 133 135 CX chemical Kinetic analysis showed that AcGH5 displayed similar activity to CtXyl5A against both WAX and RAX and was 2-fold less active against CX. RESULTS 41 50 wild type protein_state When initially measuring the activity of wild type VbGH5 against the different substrates, no clear data could be obtained, regardless of the concentration of enzyme used the reaction appeared to cease after a few minutes. RESULTS 51 56 VbGH5 protein When initially measuring the activity of wild type VbGH5 against the different substrates, no clear data could be obtained, regardless of the concentration of enzyme used the reaction appeared to cease after a few minutes. RESULTS 36 43 GH43_10 protein_type We hypothesized that the N-terminal GH43_10 rapidly removed single arabinose decorations from the arabinoxylans depleting the substrate available to the arabinoxylanase, explaining why this activity was short lived. RESULTS 67 76 arabinose chemical We hypothesized that the N-terminal GH43_10 rapidly removed single arabinose decorations from the arabinoxylans depleting the substrate available to the arabinoxylanase, explaining why this activity was short lived. RESULTS 98 111 arabinoxylans chemical We hypothesized that the N-terminal GH43_10 rapidly removed single arabinose decorations from the arabinoxylans depleting the substrate available to the arabinoxylanase, explaining why this activity was short lived. RESULTS 153 168 arabinoxylanase protein_type We hypothesized that the N-terminal GH43_10 rapidly removed single arabinose decorations from the arabinoxylans depleting the substrate available to the arabinoxylanase, explaining why this activity was short lived. RESULTS 29 38 conserved protein_state To test this hypothesis, the conserved catalytic base (Asp45) of the GH43_10 module of VbGH5 was substituted with alanine, which is predicted to inactivate this catalytic module. RESULTS 55 60 Asp45 residue_name_number To test this hypothesis, the conserved catalytic base (Asp45) of the GH43_10 module of VbGH5 was substituted with alanine, which is predicted to inactivate this catalytic module. RESULTS 69 76 GH43_10 structure_element To test this hypothesis, the conserved catalytic base (Asp45) of the GH43_10 module of VbGH5 was substituted with alanine, which is predicted to inactivate this catalytic module. RESULTS 87 92 VbGH5 protein To test this hypothesis, the conserved catalytic base (Asp45) of the GH43_10 module of VbGH5 was substituted with alanine, which is predicted to inactivate this catalytic module. RESULTS 97 113 substituted with experimental_method To test this hypothesis, the conserved catalytic base (Asp45) of the GH43_10 module of VbGH5 was substituted with alanine, which is predicted to inactivate this catalytic module. RESULTS 114 121 alanine residue_name To test this hypothesis, the conserved catalytic base (Asp45) of the GH43_10 module of VbGH5 was substituted with alanine, which is predicted to inactivate this catalytic module. RESULTS 161 177 catalytic module structure_element To test this hypothesis, the conserved catalytic base (Asp45) of the GH43_10 module of VbGH5 was substituted with alanine, which is predicted to inactivate this catalytic module. RESULTS 4 8 D45A mutant The D45A mutant did not produce arabinose consistent with the arabinofuranosidase activity displayed by the GH43_10 module in the wild type enzyme (Fig. 6). RESULTS 9 15 mutant protein_state The D45A mutant did not produce arabinose consistent with the arabinofuranosidase activity displayed by the GH43_10 module in the wild type enzyme (Fig. 6). RESULTS 32 41 arabinose chemical The D45A mutant did not produce arabinose consistent with the arabinofuranosidase activity displayed by the GH43_10 module in the wild type enzyme (Fig. 6). RESULTS 62 81 arabinofuranosidase protein_type The D45A mutant did not produce arabinose consistent with the arabinofuranosidase activity displayed by the GH43_10 module in the wild type enzyme (Fig. 6). RESULTS 108 115 GH43_10 structure_element The D45A mutant did not produce arabinose consistent with the arabinofuranosidase activity displayed by the GH43_10 module in the wild type enzyme (Fig. 6). RESULTS 130 139 wild type protein_state The D45A mutant did not produce arabinose consistent with the arabinofuranosidase activity displayed by the GH43_10 module in the wild type enzyme (Fig. 6). RESULTS 4 12 kinetics evidence The kinetics of the GH5_34 arabinoxylanase catalytic module was now measurable, and activities were determined to be between ∼6- and 10-fold lower than that of CtXyl5A. RESULTS 20 26 GH5_34 protein_type The kinetics of the GH5_34 arabinoxylanase catalytic module was now measurable, and activities were determined to be between ∼6- and 10-fold lower than that of CtXyl5A. RESULTS 27 42 arabinoxylanase protein_type The kinetics of the GH5_34 arabinoxylanase catalytic module was now measurable, and activities were determined to be between ∼6- and 10-fold lower than that of CtXyl5A. RESULTS 43 59 catalytic module structure_element The kinetics of the GH5_34 arabinoxylanase catalytic module was now measurable, and activities were determined to be between ∼6- and 10-fold lower than that of CtXyl5A. RESULTS 160 167 CtXyl5A protein The kinetics of the GH5_34 arabinoxylanase catalytic module was now measurable, and activities were determined to be between ∼6- and 10-fold lower than that of CtXyl5A. RESULTS 19 25 fungal taxonomy_domain Interestingly, the fungal arabinoxylanase displays the highest activities against WAX and RAX, ∼4- and 6-fold higher, respectively, than CtXyl5A; however, there is very little difference in the activity between the eukaryotic and prokaryotic enzymes against CX. RESULTS 26 41 arabinoxylanase protein_type Interestingly, the fungal arabinoxylanase displays the highest activities against WAX and RAX, ∼4- and 6-fold higher, respectively, than CtXyl5A; however, there is very little difference in the activity between the eukaryotic and prokaryotic enzymes against CX. RESULTS 82 85 WAX chemical Interestingly, the fungal arabinoxylanase displays the highest activities against WAX and RAX, ∼4- and 6-fold higher, respectively, than CtXyl5A; however, there is very little difference in the activity between the eukaryotic and prokaryotic enzymes against CX. RESULTS 90 93 RAX chemical Interestingly, the fungal arabinoxylanase displays the highest activities against WAX and RAX, ∼4- and 6-fold higher, respectively, than CtXyl5A; however, there is very little difference in the activity between the eukaryotic and prokaryotic enzymes against CX. RESULTS 137 144 CtXyl5A protein Interestingly, the fungal arabinoxylanase displays the highest activities against WAX and RAX, ∼4- and 6-fold higher, respectively, than CtXyl5A; however, there is very little difference in the activity between the eukaryotic and prokaryotic enzymes against CX. RESULTS 215 225 eukaryotic taxonomy_domain Interestingly, the fungal arabinoxylanase displays the highest activities against WAX and RAX, ∼4- and 6-fold higher, respectively, than CtXyl5A; however, there is very little difference in the activity between the eukaryotic and prokaryotic enzymes against CX. RESULTS 230 241 prokaryotic taxonomy_domain Interestingly, the fungal arabinoxylanase displays the highest activities against WAX and RAX, ∼4- and 6-fold higher, respectively, than CtXyl5A; however, there is very little difference in the activity between the eukaryotic and prokaryotic enzymes against CX. RESULTS 258 260 CX chemical Interestingly, the fungal arabinoxylanase displays the highest activities against WAX and RAX, ∼4- and 6-fold higher, respectively, than CtXyl5A; however, there is very little difference in the activity between the eukaryotic and prokaryotic enzymes against CX. RESULTS 70 75 AcGH5 protein Attempts to express individual modules of a variety of truncations of AcGH5 and VbGH5 were unsuccessful. RESULTS 80 85 VbGH5 protein Attempts to express individual modules of a variety of truncations of AcGH5 and VbGH5 were unsuccessful. RESULTS 97 108 full-length protein_state This may indicate that the individual modules can only fold correctly when incorporated into the full-length enzyme, demonstrating the importance of intermodule interactions to maintain the structural integrity of these enzymes. RESULTS 30 36 GH5_34 protein_type Products profile generated of GH5_34 enzymes. FIG 25 34 incubated experimental_method The enzymes at 1 μm were incubated with the four different xylans at 1% in 50 mm sodium phosphate buffer for 16 h at 37 °C (GpGH5, VbGH5, and AcGH5) or 60 °C. FIG 59 65 xylans chemical The enzymes at 1 μm were incubated with the four different xylans at 1% in 50 mm sodium phosphate buffer for 16 h at 37 °C (GpGH5, VbGH5, and AcGH5) or 60 °C. FIG 124 129 GpGH5 protein The enzymes at 1 μm were incubated with the four different xylans at 1% in 50 mm sodium phosphate buffer for 16 h at 37 °C (GpGH5, VbGH5, and AcGH5) or 60 °C. FIG 131 136 VbGH5 protein The enzymes at 1 μm were incubated with the four different xylans at 1% in 50 mm sodium phosphate buffer for 16 h at 37 °C (GpGH5, VbGH5, and AcGH5) or 60 °C. FIG 142 147 AcGH5 protein The enzymes at 1 μm were incubated with the four different xylans at 1% in 50 mm sodium phosphate buffer for 16 h at 37 °C (GpGH5, VbGH5, and AcGH5) or 60 °C. FIG 37 40 TLC experimental_method The limit products were separated by TLC. FIG 4 23 xylooligosaccharide chemical The xylooligosaccharide standards (X) are indicated by their degrees of polymerization. FIG 52 57 plant taxonomy_domain A characteristic feature of enzymes that attack the plant cell wall is their complex molecular architecture. DISCUSS 4 8 CBMs structure_element The CBMs in these enzymes generally play a role in substrate targeting and are appended to the catalytic modules through flexible linker sequences. DISCUSS 95 112 catalytic modules structure_element The CBMs in these enzymes generally play a role in substrate targeting and are appended to the catalytic modules through flexible linker sequences. DISCUSS 121 146 flexible linker sequences structure_element The CBMs in these enzymes generally play a role in substrate targeting and are appended to the catalytic modules through flexible linker sequences. DISCUSS 0 7 CtXyl5A protein CtXyl5A provides a rare visualization of the structure of multiple modules within a single enzyme. DISCUSS 45 54 structure evidence CtXyl5A provides a rare visualization of the structure of multiple modules within a single enzyme. DISCUSS 78 82 CBMs structure_element The central feature of these data is the structural role played by two of the CBMs, CtCBM6 and CtCBM13, in maintaining the active conformation of the catalytic module, CtGH5. DISCUSS 84 90 CtCBM6 structure_element The central feature of these data is the structural role played by two of the CBMs, CtCBM6 and CtCBM13, in maintaining the active conformation of the catalytic module, CtGH5. DISCUSS 95 102 CtCBM13 structure_element The central feature of these data is the structural role played by two of the CBMs, CtCBM6 and CtCBM13, in maintaining the active conformation of the catalytic module, CtGH5. DISCUSS 123 129 active protein_state The central feature of these data is the structural role played by two of the CBMs, CtCBM6 and CtCBM13, in maintaining the active conformation of the catalytic module, CtGH5. DISCUSS 150 166 catalytic module structure_element The central feature of these data is the structural role played by two of the CBMs, CtCBM6 and CtCBM13, in maintaining the active conformation of the catalytic module, CtGH5. DISCUSS 168 173 CtGH5 structure_element The central feature of these data is the structural role played by two of the CBMs, CtCBM6 and CtCBM13, in maintaining the active conformation of the catalytic module, CtGH5. DISCUSS 4 25 crystallographic data evidence The crystallographic data described here are supported by biochemical data showing either that these two modules do not bind to glycans (CtCBM13) or that the recognition of the non-reducing end of xylan or cellulose chains (CtCBM6) is unlikely to be biologically significant. DISCUSS 128 135 glycans chemical The crystallographic data described here are supported by biochemical data showing either that these two modules do not bind to glycans (CtCBM13) or that the recognition of the non-reducing end of xylan or cellulose chains (CtCBM6) is unlikely to be biologically significant. DISCUSS 137 144 CtCBM13 structure_element The crystallographic data described here are supported by biochemical data showing either that these two modules do not bind to glycans (CtCBM13) or that the recognition of the non-reducing end of xylan or cellulose chains (CtCBM6) is unlikely to be biologically significant. DISCUSS 197 202 xylan chemical The crystallographic data described here are supported by biochemical data showing either that these two modules do not bind to glycans (CtCBM13) or that the recognition of the non-reducing end of xylan or cellulose chains (CtCBM6) is unlikely to be biologically significant. DISCUSS 206 215 cellulose chemical The crystallographic data described here are supported by biochemical data showing either that these two modules do not bind to glycans (CtCBM13) or that the recognition of the non-reducing end of xylan or cellulose chains (CtCBM6) is unlikely to be biologically significant. DISCUSS 224 230 CtCBM6 structure_element The crystallographic data described here are supported by biochemical data showing either that these two modules do not bind to glycans (CtCBM13) or that the recognition of the non-reducing end of xylan or cellulose chains (CtCBM6) is unlikely to be biologically significant. DISCUSS 39 45 glycan chemical It should be emphasized, however, that glycan binding and substrate targeting may only be evident in the full-length enzyme acting on highly complex structures such as the plant cell wall, as observed recently by a CBM46 module in the Bacillus xyloglucanase/mixed linked glucanase BhCel5B. DISCUSS 105 116 full-length protein_state It should be emphasized, however, that glycan binding and substrate targeting may only be evident in the full-length enzyme acting on highly complex structures such as the plant cell wall, as observed recently by a CBM46 module in the Bacillus xyloglucanase/mixed linked glucanase BhCel5B. DISCUSS 172 177 plant taxonomy_domain It should be emphasized, however, that glycan binding and substrate targeting may only be evident in the full-length enzyme acting on highly complex structures such as the plant cell wall, as observed recently by a CBM46 module in the Bacillus xyloglucanase/mixed linked glucanase BhCel5B. DISCUSS 215 220 CBM46 structure_element It should be emphasized, however, that glycan binding and substrate targeting may only be evident in the full-length enzyme acting on highly complex structures such as the plant cell wall, as observed recently by a CBM46 module in the Bacillus xyloglucanase/mixed linked glucanase BhCel5B. DISCUSS 235 243 Bacillus taxonomy_domain It should be emphasized, however, that glycan binding and substrate targeting may only be evident in the full-length enzyme acting on highly complex structures such as the plant cell wall, as observed recently by a CBM46 module in the Bacillus xyloglucanase/mixed linked glucanase BhCel5B. DISCUSS 244 257 xyloglucanase protein_type It should be emphasized, however, that glycan binding and substrate targeting may only be evident in the full-length enzyme acting on highly complex structures such as the plant cell wall, as observed recently by a CBM46 module in the Bacillus xyloglucanase/mixed linked glucanase BhCel5B. DISCUSS 258 280 mixed linked glucanase protein_type It should be emphasized, however, that glycan binding and substrate targeting may only be evident in the full-length enzyme acting on highly complex structures such as the plant cell wall, as observed recently by a CBM46 module in the Bacillus xyloglucanase/mixed linked glucanase BhCel5B. DISCUSS 281 288 BhCel5B protein It should be emphasized, however, that glycan binding and substrate targeting may only be evident in the full-length enzyme acting on highly complex structures such as the plant cell wall, as observed recently by a CBM46 module in the Bacillus xyloglucanase/mixed linked glucanase BhCel5B. DISCUSS 0 7 CtXyl5A protein CtXyl5A is a member of GH5 that contains 6644 members. DISCUSS 23 26 GH5 protein_type CtXyl5A is a member of GH5 that contains 6644 members. DISCUSS 0 7 CtXyl5A protein CtXyl5A is a member of subfamily GH5_34. DISCUSS 33 39 GH5_34 protein_type CtXyl5A is a member of subfamily GH5_34. DISCUSS 78 94 arabinoxylanases protein_type Despite differences in sequence identity all of the homologs were shown to be arabinoxylanases. DISCUSS 68 74 GH5_34 protein_type Consistent with the conserved substrate specificity, all members of GH5_34 contained the specificity determinants Glu68, Tyr92, and Asn139, which make critical interactions with the xylose or arabinose in the −2* subsite, which are 1,3-linked to the xylose positioned in the active site. DISCUSS 89 113 specificity determinants site Consistent with the conserved substrate specificity, all members of GH5_34 contained the specificity determinants Glu68, Tyr92, and Asn139, which make critical interactions with the xylose or arabinose in the −2* subsite, which are 1,3-linked to the xylose positioned in the active site. DISCUSS 114 119 Glu68 residue_name_number Consistent with the conserved substrate specificity, all members of GH5_34 contained the specificity determinants Glu68, Tyr92, and Asn139, which make critical interactions with the xylose or arabinose in the −2* subsite, which are 1,3-linked to the xylose positioned in the active site. DISCUSS 121 126 Tyr92 residue_name_number Consistent with the conserved substrate specificity, all members of GH5_34 contained the specificity determinants Glu68, Tyr92, and Asn139, which make critical interactions with the xylose or arabinose in the −2* subsite, which are 1,3-linked to the xylose positioned in the active site. DISCUSS 132 138 Asn139 residue_name_number Consistent with the conserved substrate specificity, all members of GH5_34 contained the specificity determinants Glu68, Tyr92, and Asn139, which make critical interactions with the xylose or arabinose in the −2* subsite, which are 1,3-linked to the xylose positioned in the active site. DISCUSS 182 188 xylose chemical Consistent with the conserved substrate specificity, all members of GH5_34 contained the specificity determinants Glu68, Tyr92, and Asn139, which make critical interactions with the xylose or arabinose in the −2* subsite, which are 1,3-linked to the xylose positioned in the active site. DISCUSS 192 201 arabinose chemical Consistent with the conserved substrate specificity, all members of GH5_34 contained the specificity determinants Glu68, Tyr92, and Asn139, which make critical interactions with the xylose or arabinose in the −2* subsite, which are 1,3-linked to the xylose positioned in the active site. DISCUSS 209 220 −2* subsite site Consistent with the conserved substrate specificity, all members of GH5_34 contained the specificity determinants Glu68, Tyr92, and Asn139, which make critical interactions with the xylose or arabinose in the −2* subsite, which are 1,3-linked to the xylose positioned in the active site. DISCUSS 250 256 xylose chemical Consistent with the conserved substrate specificity, all members of GH5_34 contained the specificity determinants Glu68, Tyr92, and Asn139, which make critical interactions with the xylose or arabinose in the −2* subsite, which are 1,3-linked to the xylose positioned in the active site. DISCUSS 275 286 active site site Consistent with the conserved substrate specificity, all members of GH5_34 contained the specificity determinants Glu68, Tyr92, and Asn139, which make critical interactions with the xylose or arabinose in the −2* subsite, which are 1,3-linked to the xylose positioned in the active site. DISCUSS 18 23 CBM62 structure_element The presence of a CBM62 in CtXyl5A and AcGH5 suggests that these enzymes target highly complex xylans that contain d-galactose in their side chains. DISCUSS 27 34 CtXyl5A protein The presence of a CBM62 in CtXyl5A and AcGH5 suggests that these enzymes target highly complex xylans that contain d-galactose in their side chains. DISCUSS 39 44 AcGH5 protein The presence of a CBM62 in CtXyl5A and AcGH5 suggests that these enzymes target highly complex xylans that contain d-galactose in their side chains. DISCUSS 95 101 xylans chemical The presence of a CBM62 in CtXyl5A and AcGH5 suggests that these enzymes target highly complex xylans that contain d-galactose in their side chains. DISCUSS 115 126 d-galactose chemical The presence of a CBM62 in CtXyl5A and AcGH5 suggests that these enzymes target highly complex xylans that contain d-galactose in their side chains. DISCUSS 4 14 absence of protein_state The absence of a “non-structural” CBM in GpGH5 may indicate that this arabinoxylanase is designed to target simpler arabinoxylans present in the endosperm of cereals. DISCUSS 34 37 CBM structure_element The absence of a “non-structural” CBM in GpGH5 may indicate that this arabinoxylanase is designed to target simpler arabinoxylans present in the endosperm of cereals. DISCUSS 41 46 GpGH5 protein The absence of a “non-structural” CBM in GpGH5 may indicate that this arabinoxylanase is designed to target simpler arabinoxylans present in the endosperm of cereals. DISCUSS 70 85 arabinoxylanase protein_type The absence of a “non-structural” CBM in GpGH5 may indicate that this arabinoxylanase is designed to target simpler arabinoxylans present in the endosperm of cereals. DISCUSS 116 129 arabinoxylans chemical The absence of a “non-structural” CBM in GpGH5 may indicate that this arabinoxylanase is designed to target simpler arabinoxylans present in the endosperm of cereals. DISCUSS 158 165 cereals taxonomy_domain The absence of a “non-structural” CBM in GpGH5 may indicate that this arabinoxylanase is designed to target simpler arabinoxylans present in the endosperm of cereals. DISCUSS 48 54 GH5_34 protein_type Although the characterization of all members of GH5_34 suggests that this subfamily is monospecific, differences in specificity are observed in other subfamilies of GHs including GH43 and GH5. DISCUSS 165 168 GHs protein_type Although the characterization of all members of GH5_34 suggests that this subfamily is monospecific, differences in specificity are observed in other subfamilies of GHs including GH43 and GH5. DISCUSS 179 183 GH43 protein_type Although the characterization of all members of GH5_34 suggests that this subfamily is monospecific, differences in specificity are observed in other subfamilies of GHs including GH43 and GH5. DISCUSS 188 191 GH5 protein_type Although the characterization of all members of GH5_34 suggests that this subfamily is monospecific, differences in specificity are observed in other subfamilies of GHs including GH43 and GH5. DISCUSS 24 30 GH5_34 protein_type Thus, as new members of GH5_34 are identified from genomic sequence data and subsequently characterized, the specificity of this family may require reinterpretation. DISCUSS 25 30 VbGH5 protein An intriguing feature of VbGH5 is that the limited products generated by this enzymes are much larger than those produced by the other arabinoxylanases. DISCUSS 135 151 arabinoxylanases protein_type An intriguing feature of VbGH5 is that the limited products generated by this enzymes are much larger than those produced by the other arabinoxylanases. DISCUSS 28 37 arabinose chemical This suggests that although arabinose decorations contribute to enzyme specificity (VbGH5 is not active on xylans lacking arabinose side chains), the enzyme requires other specificity determinants that occur less frequently in arabinoxylans. DISCUSS 84 89 VbGH5 protein This suggests that although arabinose decorations contribute to enzyme specificity (VbGH5 is not active on xylans lacking arabinose side chains), the enzyme requires other specificity determinants that occur less frequently in arabinoxylans. DISCUSS 107 113 xylans chemical This suggests that although arabinose decorations contribute to enzyme specificity (VbGH5 is not active on xylans lacking arabinose side chains), the enzyme requires other specificity determinants that occur less frequently in arabinoxylans. DISCUSS 122 131 arabinose chemical This suggests that although arabinose decorations contribute to enzyme specificity (VbGH5 is not active on xylans lacking arabinose side chains), the enzyme requires other specificity determinants that occur less frequently in arabinoxylans. DISCUSS 227 240 arabinoxylans chemical This suggests that although arabinose decorations contribute to enzyme specificity (VbGH5 is not active on xylans lacking arabinose side chains), the enzyme requires other specificity determinants that occur less frequently in arabinoxylans. DISCUSS 50 54 GH98 protein_type This has some resonance with a recently described GH98 xylanase that also exploits specificity determinants that occur infrequently and are only evident in highly complex xylans (e.g. CX). DISCUSS 55 63 xylanase protein_type This has some resonance with a recently described GH98 xylanase that also exploits specificity determinants that occur infrequently and are only evident in highly complex xylans (e.g. CX). DISCUSS 171 177 xylans chemical This has some resonance with a recently described GH98 xylanase that also exploits specificity determinants that occur infrequently and are only evident in highly complex xylans (e.g. CX). DISCUSS 184 186 CX chemical This has some resonance with a recently described GH98 xylanase that also exploits specificity determinants that occur infrequently and are only evident in highly complex xylans (e.g. CX). DISCUSS 86 102 arabinoxylanases protein_type To conclude, this study provides the molecular basis for the specificity displayed by arabinoxylanases. DISCUSS 42 48 pocket site Substrate specificity is dominated by the pocket that binds single arabinose or xylose side chains. DISCUSS 67 76 arabinose chemical Substrate specificity is dominated by the pocket that binds single arabinose or xylose side chains. DISCUSS 80 86 xylose chemical Substrate specificity is dominated by the pocket that binds single arabinose or xylose side chains. DISCUSS 4 8 open protein_state The open xylan binding cleft explains why the enzyme is able to attack highly decorated forms of the hemicellulose. DISCUSS 9 28 xylan binding cleft site The open xylan binding cleft explains why the enzyme is able to attack highly decorated forms of the hemicellulose. DISCUSS 101 114 hemicellulose chemical The open xylan binding cleft explains why the enzyme is able to attack highly decorated forms of the hemicellulose. DISCUSS 45 62 catalytic modules structure_element It is also evident that appending additional catalytic modules and CBMs onto the core components of these enzymes generates bespoke arabinoxylanases with activities optimized for specific functions. DISCUSS 67 71 CBMs structure_element It is also evident that appending additional catalytic modules and CBMs onto the core components of these enzymes generates bespoke arabinoxylanases with activities optimized for specific functions. DISCUSS 132 148 arabinoxylanases protein_type It is also evident that appending additional catalytic modules and CBMs onto the core components of these enzymes generates bespoke arabinoxylanases with activities optimized for specific functions. DISCUSS 25 41 arabinoxylanases protein_type The specificities of the arabinoxylanases described here are distinct from the classical endo-xylanases and thus have the potential to contribute to the toolbox of biocatalysts required by industries that exploit the plant cell wall as a sustainable substrate. DISCUSS 89 103 endo-xylanases protein_type The specificities of the arabinoxylanases described here are distinct from the classical endo-xylanases and thus have the potential to contribute to the toolbox of biocatalysts required by industries that exploit the plant cell wall as a sustainable substrate. DISCUSS 217 222 plant taxonomy_domain The specificities of the arabinoxylanases described here are distinct from the classical endo-xylanases and thus have the potential to contribute to the toolbox of biocatalysts required by industries that exploit the plant cell wall as a sustainable substrate. DISCUSS 0 41 Data collection and refinement statistics evidence Data collection and refinement statistics TABLE 1 10 CtXyl5A-D mutant " CtXyl5A-D GH5-CBM6-Arap GH5-CBM6-Xylp GH5-CBM6- (Araf-Xylp4) Data collection     Source ESRF-ID14-1 Diamond I04–1 Diamond I24 Diamond I02     Wavelength (Å) 0.9334 0.9173 0.9772 0.9791     Space group P21212 P212121 P212121 P212121     Cell dimensions         a, b, c (Å) 147.4, 191.7, 50.7 67.1, 72.4, 109.1 67.9, 72.5, 109.5 76.3, 123.2, 125.4         α, β, γ (°) 90, 90, 90 90, 90, 90 90, 90, 90 90, 90, 90     No. of measured reflections 244,475 (29,324) 224,842 (11,281) 152,004 (4,996) 463,237 (23,068)     No. of independent reflections 42246 (5,920) 63,523 (3,175) 42,716 (2,334) 140,288 (6,879)     Resolution (Å) 50.70–2.64 (2.78–2.64) 44.85–1.65 (1.68–1.65) 45.16–1.90 (1.94–1.90) 48.43–1.65 (1.68–1.65)     Rmerge (%) 16.5 (69.5) 6.7 (65.1) 2.8 (8.4) 5.7 (74.9)     CC1/2 0.985 (0.478) 0.998 (0.594) 0.999 (0.982) 0.998 (0.484)     I/σI 8.0 (2.0) 13 (1.6) 26.6 (8.0) 11.2 (1.6)     Completeness (%) 98.5 (96.4) 98.5 (99.4) 98.6 (85.0) 98.8 (99.4)     Redundancy 5.8 (5.0) 3.5 (3.6) 3.6 (2.1) 3.3 (3.4) Refinement     Rwork/Rfree 23.7/27.8 12.2/17.0 12.9/16.1 14.5/19.9     No. atoms         Protein 5446 3790 3729 7333         Ligand 19 20 20 92         Water 227 579 601 923     B-factors         Protein 41.6 17.8 15.8 21.0         Ligand 65.0 19.4 24.2 39.5         Water 35.4 38.5 32.2 37.6     R.m.s deviations         Bond lengths (Å) 0.008 0.015 0.012 0.012         Bond angles (°) 1.233 1.502 1.624 1.554     Protein Data Bank code 5G56 5LA0 5LA1 2LA2 " TABLE 11 24 GH5-CBM6-Arap complex_assembly " CtXyl5A-D GH5-CBM6-Arap GH5-CBM6-Xylp GH5-CBM6- (Araf-Xylp4) Data collection     Source ESRF-ID14-1 Diamond I04–1 Diamond I24 Diamond I02     Wavelength (Å) 0.9334 0.9173 0.9772 0.9791     Space group P21212 P212121 P212121 P212121     Cell dimensions         a, b, c (Å) 147.4, 191.7, 50.7 67.1, 72.4, 109.1 67.9, 72.5, 109.5 76.3, 123.2, 125.4         α, β, γ (°) 90, 90, 90 90, 90, 90 90, 90, 90 90, 90, 90     No. of measured reflections 244,475 (29,324) 224,842 (11,281) 152,004 (4,996) 463,237 (23,068)     No. of independent reflections 42246 (5,920) 63,523 (3,175) 42,716 (2,334) 140,288 (6,879)     Resolution (Å) 50.70–2.64 (2.78–2.64) 44.85–1.65 (1.68–1.65) 45.16–1.90 (1.94–1.90) 48.43–1.65 (1.68–1.65)     Rmerge (%) 16.5 (69.5) 6.7 (65.1) 2.8 (8.4) 5.7 (74.9)     CC1/2 0.985 (0.478) 0.998 (0.594) 0.999 (0.982) 0.998 (0.484)     I/σI 8.0 (2.0) 13 (1.6) 26.6 (8.0) 11.2 (1.6)     Completeness (%) 98.5 (96.4) 98.5 (99.4) 98.6 (85.0) 98.8 (99.4)     Redundancy 5.8 (5.0) 3.5 (3.6) 3.6 (2.1) 3.3 (3.4) Refinement     Rwork/Rfree 23.7/27.8 12.2/17.0 12.9/16.1 14.5/19.9     No. atoms         Protein 5446 3790 3729 7333         Ligand 19 20 20 92         Water 227 579 601 923     B-factors         Protein 41.6 17.8 15.8 21.0         Ligand 65.0 19.4 24.2 39.5         Water 35.4 38.5 32.2 37.6     R.m.s deviations         Bond lengths (Å) 0.008 0.015 0.012 0.012         Bond angles (°) 1.233 1.502 1.624 1.554     Protein Data Bank code 5G56 5LA0 5LA1 2LA2 " TABLE 25 38 GH5-CBM6-Xylp complex_assembly " CtXyl5A-D GH5-CBM6-Arap GH5-CBM6-Xylp GH5-CBM6- (Araf-Xylp4) Data collection     Source ESRF-ID14-1 Diamond I04–1 Diamond I24 Diamond I02     Wavelength (Å) 0.9334 0.9173 0.9772 0.9791     Space group P21212 P212121 P212121 P212121     Cell dimensions         a, b, c (Å) 147.4, 191.7, 50.7 67.1, 72.4, 109.1 67.9, 72.5, 109.5 76.3, 123.2, 125.4         α, β, γ (°) 90, 90, 90 90, 90, 90 90, 90, 90 90, 90, 90     No. of measured reflections 244,475 (29,324) 224,842 (11,281) 152,004 (4,996) 463,237 (23,068)     No. of independent reflections 42246 (5,920) 63,523 (3,175) 42,716 (2,334) 140,288 (6,879)     Resolution (Å) 50.70–2.64 (2.78–2.64) 44.85–1.65 (1.68–1.65) 45.16–1.90 (1.94–1.90) 48.43–1.65 (1.68–1.65)     Rmerge (%) 16.5 (69.5) 6.7 (65.1) 2.8 (8.4) 5.7 (74.9)     CC1/2 0.985 (0.478) 0.998 (0.594) 0.999 (0.982) 0.998 (0.484)     I/σI 8.0 (2.0) 13 (1.6) 26.6 (8.0) 11.2 (1.6)     Completeness (%) 98.5 (96.4) 98.5 (99.4) 98.6 (85.0) 98.8 (99.4)     Redundancy 5.8 (5.0) 3.5 (3.6) 3.6 (2.1) 3.3 (3.4) Refinement     Rwork/Rfree 23.7/27.8 12.2/17.0 12.9/16.1 14.5/19.9     No. atoms         Protein 5446 3790 3729 7333         Ligand 19 20 20 92         Water 227 579 601 923     B-factors         Protein 41.6 17.8 15.8 21.0         Ligand 65.0 19.4 24.2 39.5         Water 35.4 38.5 32.2 37.6     R.m.s deviations         Bond lengths (Å) 0.008 0.015 0.012 0.012         Bond angles (°) 1.233 1.502 1.624 1.554     Protein Data Bank code 5G56 5LA0 5LA1 2LA2 " TABLE 39 61 GH5-CBM6- (Araf-Xylp4) complex_assembly " CtXyl5A-D GH5-CBM6-Arap GH5-CBM6-Xylp GH5-CBM6- (Araf-Xylp4) Data collection     Source ESRF-ID14-1 Diamond I04–1 Diamond I24 Diamond I02     Wavelength (Å) 0.9334 0.9173 0.9772 0.9791     Space group P21212 P212121 P212121 P212121     Cell dimensions         a, b, c (Å) 147.4, 191.7, 50.7 67.1, 72.4, 109.1 67.9, 72.5, 109.5 76.3, 123.2, 125.4         α, β, γ (°) 90, 90, 90 90, 90, 90 90, 90, 90 90, 90, 90     No. of measured reflections 244,475 (29,324) 224,842 (11,281) 152,004 (4,996) 463,237 (23,068)     No. of independent reflections 42246 (5,920) 63,523 (3,175) 42,716 (2,334) 140,288 (6,879)     Resolution (Å) 50.70–2.64 (2.78–2.64) 44.85–1.65 (1.68–1.65) 45.16–1.90 (1.94–1.90) 48.43–1.65 (1.68–1.65)     Rmerge (%) 16.5 (69.5) 6.7 (65.1) 2.8 (8.4) 5.7 (74.9)     CC1/2 0.985 (0.478) 0.998 (0.594) 0.999 (0.982) 0.998 (0.484)     I/σI 8.0 (2.0) 13 (1.6) 26.6 (8.0) 11.2 (1.6)     Completeness (%) 98.5 (96.4) 98.5 (99.4) 98.6 (85.0) 98.8 (99.4)     Redundancy 5.8 (5.0) 3.5 (3.6) 3.6 (2.1) 3.3 (3.4) Refinement     Rwork/Rfree 23.7/27.8 12.2/17.0 12.9/16.1 14.5/19.9     No. atoms         Protein 5446 3790 3729 7333         Ligand 19 20 20 92         Water 227 579 601 923     B-factors         Protein 41.6 17.8 15.8 21.0         Ligand 65.0 19.4 24.2 39.5         Water 35.4 38.5 32.2 37.6     R.m.s deviations         Bond lengths (Å) 0.008 0.015 0.012 0.012         Bond angles (°) 1.233 1.502 1.624 1.554     Protein Data Bank code 5G56 5LA0 5LA1 2LA2 " TABLE 1079 1084 Rwork evidence " CtXyl5A-D GH5-CBM6-Arap GH5-CBM6-Xylp GH5-CBM6- (Araf-Xylp4) Data collection     Source ESRF-ID14-1 Diamond I04–1 Diamond I24 Diamond I02     Wavelength (Å) 0.9334 0.9173 0.9772 0.9791     Space group P21212 P212121 P212121 P212121     Cell dimensions         a, b, c (Å) 147.4, 191.7, 50.7 67.1, 72.4, 109.1 67.9, 72.5, 109.5 76.3, 123.2, 125.4         α, β, γ (°) 90, 90, 90 90, 90, 90 90, 90, 90 90, 90, 90     No. of measured reflections 244,475 (29,324) 224,842 (11,281) 152,004 (4,996) 463,237 (23,068)     No. of independent reflections 42246 (5,920) 63,523 (3,175) 42,716 (2,334) 140,288 (6,879)     Resolution (Å) 50.70–2.64 (2.78–2.64) 44.85–1.65 (1.68–1.65) 45.16–1.90 (1.94–1.90) 48.43–1.65 (1.68–1.65)     Rmerge (%) 16.5 (69.5) 6.7 (65.1) 2.8 (8.4) 5.7 (74.9)     CC1/2 0.985 (0.478) 0.998 (0.594) 0.999 (0.982) 0.998 (0.484)     I/σI 8.0 (2.0) 13 (1.6) 26.6 (8.0) 11.2 (1.6)     Completeness (%) 98.5 (96.4) 98.5 (99.4) 98.6 (85.0) 98.8 (99.4)     Redundancy 5.8 (5.0) 3.5 (3.6) 3.6 (2.1) 3.3 (3.4) Refinement     Rwork/Rfree 23.7/27.8 12.2/17.0 12.9/16.1 14.5/19.9     No. atoms         Protein 5446 3790 3729 7333         Ligand 19 20 20 92         Water 227 579 601 923     B-factors         Protein 41.6 17.8 15.8 21.0         Ligand 65.0 19.4 24.2 39.5         Water 35.4 38.5 32.2 37.6     R.m.s deviations         Bond lengths (Å) 0.008 0.015 0.012 0.012         Bond angles (°) 1.233 1.502 1.624 1.554     Protein Data Bank code 5G56 5LA0 5LA1 2LA2 " TABLE 1085 1090 Rfree evidence " CtXyl5A-D GH5-CBM6-Arap GH5-CBM6-Xylp GH5-CBM6- (Araf-Xylp4) Data collection     Source ESRF-ID14-1 Diamond I04–1 Diamond I24 Diamond I02     Wavelength (Å) 0.9334 0.9173 0.9772 0.9791     Space group P21212 P212121 P212121 P212121     Cell dimensions         a, b, c (Å) 147.4, 191.7, 50.7 67.1, 72.4, 109.1 67.9, 72.5, 109.5 76.3, 123.2, 125.4         α, β, γ (°) 90, 90, 90 90, 90, 90 90, 90, 90 90, 90, 90     No. of measured reflections 244,475 (29,324) 224,842 (11,281) 152,004 (4,996) 463,237 (23,068)     No. of independent reflections 42246 (5,920) 63,523 (3,175) 42,716 (2,334) 140,288 (6,879)     Resolution (Å) 50.70–2.64 (2.78–2.64) 44.85–1.65 (1.68–1.65) 45.16–1.90 (1.94–1.90) 48.43–1.65 (1.68–1.65)     Rmerge (%) 16.5 (69.5) 6.7 (65.1) 2.8 (8.4) 5.7 (74.9)     CC1/2 0.985 (0.478) 0.998 (0.594) 0.999 (0.982) 0.998 (0.484)     I/σI 8.0 (2.0) 13 (1.6) 26.6 (8.0) 11.2 (1.6)     Completeness (%) 98.5 (96.4) 98.5 (99.4) 98.6 (85.0) 98.8 (99.4)     Redundancy 5.8 (5.0) 3.5 (3.6) 3.6 (2.1) 3.3 (3.4) Refinement     Rwork/Rfree 23.7/27.8 12.2/17.0 12.9/16.1 14.5/19.9     No. atoms         Protein 5446 3790 3729 7333         Ligand 19 20 20 92         Water 227 579 601 923     B-factors         Protein 41.6 17.8 15.8 21.0         Ligand 65.0 19.4 24.2 39.5         Water 35.4 38.5 32.2 37.6     R.m.s deviations         Bond lengths (Å) 0.008 0.015 0.012 0.012         Bond angles (°) 1.233 1.502 1.624 1.554     Protein Data Bank code 5G56 5LA0 5LA1 2LA2 " TABLE 0 2 GH protein_type GH SUPPL 0 19 glycoside hydrolase protein_type glycoside hydrolase SUPPL 0 7 CtXyl5A protein CtXyl5A SUPPL 0 15 C. thermocellum species C. thermocellum arabinoxylanase SUPPL 16 31 arabinoxylanase protein_type C. thermocellum arabinoxylanase SUPPL 0 3 CBM structure_element CBM SUPPL 0 41 non-catalytic carbohydrate binding module structure_element non-catalytic carbohydrate binding module SUPPL 0 2 Fn protein_type Fn SUPPL 0 11 fibronectin protein_type fibronectin SUPPL 0 3 WAX chemical WAX SUPPL 0 5 wheat taxonomy_domain wheat arabinoxylan SUPPL 6 18 arabinoxylan chemical wheat arabinoxylan SUPPL 0 3 RAX chemical RAX SUPPL 0 3 rye taxonomy_domain rye arabinoxylan SUPPL 4 16 arabinoxylan chemical rye arabinoxylan SUPPL 0 2 CX chemical CX SUPPL 0 4 corn taxonomy_domain corn bran xylan SUPPL 10 15 xylan chemical corn bran xylan SUPPL 0 5 HPAEC experimental_method HPAEC SUPPL 0 46 high performance anion exchange chromatography experimental_method high performance anion exchange chromatography SUPPL 0 9 birchwood taxonomy_domain birchwood xylan SUPPL 10 15 xylan chemical birchwood xylan SUPPL 0 23 electrospray ionization experimental_method electrospray ionization. SUPPL