text_1: The artifactual C-terminal helix swapping in the StART domain is observed in the Ups1-Mdm35 heterodimer of the StARkin superfamily.
text_2: Here we focused on the Ups1-Mdm35 system, which mediates phosphatidic acid (PA) transfer between the outer and inner mitochondrial membranes, and determined the X-ray structures of Mdm35 and Ups1-Mdm35 with and without PA.