Okazaki Institute for Integrative Bioscience, Institute for Molecular Science, National Institutes of Natural Sciences, Aichi 444-8787, Japan; Department of Functional Molecular Science, School of Physical Sciences, The Graduate University for Advanced Studies (SOKENDAI), Kanagawa 240-0193, Japan.
Department of Physics, Faculty of Science and Engineering, Chuo University, Tokyo 112-8551, Japan.
Curr Opin Struct Biol. 2015 Apr;31:49-56. doi: 10.1016/j.sbi.2015.02.013. Epub 2015 Mar 19.
In ion-transporting rotary ATPases, the mechanical rotation of inner rotor subunits against other stator subunits in the complex mediates conversion of chemical free energy from ATP hydrolysis into electrochemical potential by pumping ions across the cell membrane. To fully understand the rotational mechanism of energy conversion, it is essential to analyze a target sample by multiple advanced methods that differ in spatiotemporal resolutions and sample environments. Here, we describe such a strategy applied to the water-soluble V1 moiety of Enterococcus hirae V-ATPase; this strategy involves integration of crystal structure studies and single-molecule analysis of rotary dynamics and torque generation. In addition, we describe our current model of the chemo-mechanical coupling scheme obtained by this approach, as well as future prospects.
在离子转运旋转 ATP 酶中，复合物中内转子亚基相对于其他定子亚基的机械旋转介导了将化学自由能从 ATP 水解转化为电化学势，通过将离子泵过细胞膜。为了充分理解能量转换的旋转机制，通过在时空分辨率和样品环境方面有所不同的多种先进方法来分析目标样品是至关重要的。在这里，我们描述了将该策略应用于 Enterococcus hirae V-ATPase 的水溶性 V1 部分的情况；该策略涉及晶体结构研究和旋转动力学以及扭矩产生的单分子分析的整合。此外，我们还描述了通过这种方法获得的化学机械偶联方案的当前模型，以及未来的前景。
