Molecular, Structural and Computational Biology Division, The Victor Chang Cardiac Research Institute, Darlinghurst, NSW, Australia.
Faculty of Medicine, St Vincent's Clinical School, UNSW Sydney, Kensington, NSW, Australia.
Nat Commun. 2021 Aug 3;12(1):4690. doi: 10.1038/s41467-021-25029-0.
FF ATP synthase interchanges phosphate transfer energy and proton motive force via a rotary catalysis mechanism. Isolated F-ATPase catalytic cores can hydrolyze ATP, passing through six intermediate conformational states to generate rotation of their central γ-subunit. Although previous structural studies have contributed greatly to understanding rotary catalysis in the F-ATPase, the structure of an important conformational state (the binding-dwell) has remained elusive. Here, we exploit temperature and time-resolved cryo-electron microscopy to determine the structure of the binding- and catalytic-dwell states of Bacillus PS3 F-ATPase. Each state shows three catalytic β-subunits in different conformations, establishing the complete set of six states taken up during the catalytic cycle and providing molecular details for both the ATP binding and hydrolysis strokes. We also identify a potential phosphate-release tunnel that indicates how ADP and phosphate binding are coordinated during synthesis. Overall these findings provide a structural basis for the entire F-ATPase catalytic cycle.
FF ATP 合酶通过旋转催化机制交换磷酸转移能量和质子动力势。分离的 F-ATP 酶催化核心可以水解 ATP，通过六个中间构象状态生成其中心 γ-亚基的旋转。尽管先前的结构研究对理解 F-ATP 酶的旋转催化有很大贡献，但一个重要构象状态（结合停留）的结构仍然难以捉摸。在这里，我们利用温度和时间分辨的冷冻电子显微镜来确定 Bacillus PS3 F-ATP 酶的结合和催化停留状态的结构。每个状态显示三个不同构象的催化β-亚基，建立了催化循环中采用的完整的六个状态集，并为 ATP 结合和水解冲程提供了分子细节。我们还确定了一个潜在的磷酸盐释放隧道，表明在合成过程中如何协调 ADP 和磷酸盐的结合。总的来说，这些发现为整个 F-ATP 酶催化循环提供了结构基础。
