High-resolution cryo-EM analysis of the yeast ATP synthase in a lipid membrane

Mitochondrial adenosine triphosphate (ATP) synthase comprises a membrane embedded Fo motor that rotates to drive ATP synthesis in the F1 subunit. We used single-particle cryo–electron microscopy (cryo-EM) to obtain structures of the full complex in a lipid bilayer in the absence or presence of the inhibitor oligomycin at 3.6- and 3.8-angstrom resolution, respectively. To limit conformational heterogeneity, we locked the rotor in a single conformation by fusing the F6 subunit of the stator with the subunit of the rotor. Assembly of the enzyme with the F6- fusion caused a twisting of the rotor and a 9° rotation of the Fo c10-ring in the direction of ATP synthesis, relative to the structure of isolated Fo. Our cryo-EM structures show how F1 and Fo are coupled, give insight into the proton translocation pathway, and show how oligomycin blocks ATP synthesis.

Source: ScienceNOW - May 10, 2018 Category: Science Authors: Srivastava, A. P., Luo, M., Zhou, W., Symersky, J., Bai, D., Chambers, M. G., Faraldo-Gomez, J. D., Liao, M., Mueller, D. M. Tags: Biochemistry, Online Only r-articles Source Type: news