双向细菌鞭毛马达中扭矩产生的结构基础。

Structural basis of torque generation in the bi-directional bacterial flagellar motor.

作者信息

Hu Haidai, Santiveri Mònica, Wadhwa Navish, Berg Howard C, Erhardt Marc, Taylor Nicholas M I

机构信息

Structural Biology of Molecular Machines Group, Protein Structure & Function Program, Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark.

Department of Molecular and Cellular Biology, Harvard University, 16 Divinity Avenue, Cambridge, MA 02138, USA; Rowland Institute at Harvard, Harvard University, 100 Edwin H. Land Blvd, Cambridge, MA 02142, USA.

出版信息

Trends Biochem Sci. 2022 Feb;47(2):160-172. doi: 10.1016/j.tibs.2021.06.005. Epub 2021 Jul 19.

DOI:10.1016/j.tibs.2021.06.005

PMID:34294545

Abstract

The flagellar stator unit is an oligomeric complex of two membrane proteins (MotAB) that powers bi-directional rotation of the bacterial flagellum. Harnessing the ion motive force across the cytoplasmic membrane, the stator unit operates as a miniature rotary motor itself to provide torque for rotation of the flagellum. Recent cryo-electron microscopic (cryo-EM) structures of the stator unit provided novel insights into its assembly, function, and subunit stoichiometry, revealing the ion flux pathway and the torque generation mechanism. Furthermore, in situ cryo-electron tomography (cryo-ET) studies revealed unprecedented details of the interactions between stator unit and rotor. In this review, we summarize recent advances in our understanding of the structure and function of the flagellar stator unit, torque generation, and directional switching of the motor.

摘要

鞭毛定子单元是由两种膜蛋白（MotAB）组成的寡聚复合物，为细菌鞭毛的双向旋转提供动力。定子单元利用跨细胞质膜的离子动力，自身作为一个微型旋转电机运行，为鞭毛的旋转提供扭矩。最近定子单元的冷冻电子显微镜（cryo-EM）结构为其组装、功能和亚基化学计量提供了新的见解，揭示了离子通量途径和扭矩产生机制。此外，原位冷冻电子断层扫描（cryo-ET）研究揭示了定子单元与转子之间相互作用的前所未有的细节。在这篇综述中，我们总结了在理解鞭毛定子单元的结构和功能、扭矩产生以及电机方向切换方面的最新进展。