Department of Biological Chemistry and Molecular Biology, Chicago Medical School, Rosalind Franklin University, 3333 Green Bay Road, North Chicago, IL 60064, USA.
Department of Cell Biology, Harvard Medical School, 250 Longwood Avenue, SGM 509, Boston, MA 02115, USA.
Science. 2018 May 11;360(6389). doi: 10.1126/science.aas9699. Epub 2018 Apr 12.
Mitochondrial adenosine triphosphate (ATP) synthase comprises a membrane embedded F motor that rotates to drive ATP synthesis in the F 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 δ subunit of the rotor. Assembly of the enzyme with the F6-δ fusion caused a twisting of the rotor and a 9° rotation of the F c-ring in the direction of ATP synthesis, relative to the structure of isolated F Our cryo-EM structures show how F and F are coupled, give insight into the proton translocation pathway, and show how oligomycin blocks ATP synthesis.
线粒体三磷酸腺苷（ATP）合酶由一个嵌入膜中的 F 马达组成，该马达旋转以驱动 F 亚基中的 ATP 合成。我们使用单颗粒冷冻电镜（cryo-EM）分别在 3.6 和 3.8 埃的分辨率下获得了在脂质双层中无抑制剂寡霉素和存在抑制剂寡霉素时完整复合物的结构。为了限制构象异质性，我们通过将定子的 F6 亚基与转子的 δ 亚基融合，将转子锁定在单一构象中。酶与 F6-δ 融合的组装导致转子扭曲，以及 F c 环相对于游离 F 的方向旋转 9°。我们的 cryo-EM 结构显示了 F 和 F 如何偶联，深入了解质子转移途径，并显示了寡霉素如何阻断 ATP 合成。
