Internal and external components of the bacterial flagellar motor rotate as a unit
Internal and external components of the bacterial flagellar motor rotate as a unit
复制标题
DOI：
10.1073/pnas.1511691113
复制
发表时间：
2016-04-26
影响因子：
11.1
通讯作者：
Berg, Howard C.
中科院分区：
文献类型：
--
作者：
Hosu, Basarab G.;Nathan, Vedavalli S. J.;Berg, Howard C.
大多数游泳的细菌，包括大肠杆菌，都是由螺旋丝推动的，每根螺旋丝的底部都由质子或钠离子电化学梯度驱动的旋转电机驱动。每个电机包含许多定子复合体，包括 4MotA 2MotB 或 4PomA 2PomB，这些蛋白质锚定在细胞壁的刚性肽聚糖层上。这些蛋白质对跨越内膜的转子施加扭矩。连接到转子的轴通过衬套、P 环和 L 环穿过肽聚糖和外膜，通过称为钩的柔性联轴器连接到灯丝。尽管已知外部组件（钩子和灯丝）会旋转，并被拴在玻璃上或用乳胶珠标记，但内部组件的旋转仍然只是一个合理的假设。在这里，通过使用偏振光漂白和探测内部 YFP-FliN 融合，我们发现细胞质环最内部的成分以与钩子相似的速度旋转。
Most bacteria that swim, including Escherichia coli, are propelled by helical filaments, each driven at its base by a rotary motor powered by a proton or a sodium ion electrochemical gradient. Each motor contains a number of stator complexes, comprising 4MotA 2MotB or 4PomA 2PomB, proteins anchored to the rigid peptidoglycan layer of the cell wall. These proteins exert torque on a rotor that spans the inner membrane. A shaft connected to the rotor passes through the peptidoglycan and the outer membrane through bushings, the P and L rings, connecting to the filament by a flexible coupling known as the hook. Although the external components, the hook and the filament, are known to rotate, having been tethered to glass or marked by latex beads, the rotation of the internal components has remained only a reasonable assumption. Here, by using polarized light to bleach and probe an internal YFP-FliN fusion, we show that the innermost components of the cytoplasmic ring rotate at a rate similar to that of the hook.