sentence: When expressed in sbh1 Δ sbh2 Δ cells this double mutant ( DM ) was unable to rescue the temperature-sensitive growth phenotype at 38.5 ° C whereas the single mutants P54S ( SM1 ) and V57G ( SM2 ) were as efficient as the wild type SBH1 to rescue the temperature-sensitive growth of sbh1 Δ sbh2 Δ cells ( Figure 3B ) .