Furlong Emily J, Reininger-Chatzigiannakis Ian-Blaine P, Zeng Yi C, Brown Simon H J, Sobti Meghna, Stewart Alastair G
Molecular, Structural and Computational Biology Division, The Victor Chang Cardiac Research Institute, Darlinghurst, Australia.
Division of Biomedical Science and Biochemistry, Research School of Biology, Australian National University, Acton, ACT, Australia.
bioRxiv. 2024 Aug 9:2024.08.08.607276. doi: 10.1101/2024.08.08.607276.
FF ATP synthase is a molecular rotary motor that can generate ATP using a transmembrane proton motive force. Isolated F-ATPase catalytic cores can hydrolyse ATP, passing through a series of conformational states involving rotation of the central γ rotor subunit and the opening and closing of the catalytic β subunits. Cooperativity in F-ATPase has long thought to be conferred through the γ subunit, with three key interaction sites between the γ and β subunits being identified. Single molecule studies have demonstrated that the F complexes lacking the γ axle still "rotate" and hydrolyse ATP, but with less efficiency. We solved the cryogenic electron microscopy structure of an axle-less sp. PS3 F-ATPase. The unexpected binding-dwell conformation of the structure in combination with the observed lack of interactions between the axle-less γ and the open β subunit suggests that the complete γ subunit is important for coordinating efficient ATP binding of F-ATPase.
F型ATP合酶是一种分子旋转马达，可利用跨膜质子动力势产生ATP。分离的F型ATP酶催化核心可以水解ATP，经历一系列构象状态，包括中央γ转子亚基的旋转以及催化β亚基的打开和关闭。长期以来，人们一直认为F型ATP酶中的协同作用是通过γ亚基实现的，已确定γ亚基和β亚基之间有三个关键相互作用位点。单分子研究表明，缺乏γ轴的F复合物仍能“旋转”并水解ATP，但效率较低。我们解析了无轴的嗜热栖热菌F型ATP酶的低温电子显微镜结构。该结构意外的结合驻留构象，以及观察到的无轴γ亚基与开放β亚基之间缺乏相互作用，表明完整的γ亚基对于协调F型ATP酶有效的ATP结合很重要。
