Limiting (zero-load) speed of the rotary motor of Escherichia coli is independent of the number of torque-generating units
Limiting (zero-load) speed of the rotary motor of Escherichia coli is independent of the number of torque-generating units
复制标题
大肠杆菌旋转电机的极限（零负载）速度与扭矩产生单元的数量无关
DOI：
10.1073/pnas.1713655114
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发表时间：
2017-11
影响因子：
11.1
通讯作者：
Yuan Junhua
中科院分区：
文献类型：
--
作者：
Wang Bin;Zhang Rongjing;Yuan Junhua
细菌鞭毛马达的旋转由多个扭矩产生单元驱动。单元的占空比定义为单元与转子接合的时间分数，表征了电机的扭矩产生动态。我们的数据表明，电机的极限速度是独立的扭矩产生单位的数量为鞭毛电机在大肠杆菌，确凿地表明，单位有一个占空比接近1。细菌鞭毛马达的旋转由多个扭矩产生单元（定子元件）驱动。扭矩产生动力学可以根据定子元件的“占空比”来理解，即，定子元件在其机械化学循环期间与转子接合的时间分数。电动机的极限转速（零负载转速）对定子元件数量的依赖性是占空比的决定性测试，在过去的十年里，这在实验和理论上一直存在争议。在这里，我们开发了一种方法相结合的激光暗场显微镜和光学捕获来解决这个争议。我们发现，零负载速度是独立的定子元件的数量为细菌鞭毛电机在大肠杆菌，表明这些元素有一个占空比接近1。
Significance Rotation of the bacterial flagellar motor is driven by multiple torque-generating units. The duty ratio of the units, defined as the fraction of time that a unit engages with the rotor, characterizes the torque-generating dynamics of the motor. Our data showed that the limiting speed of the motor is independent of the number of torque-generating units for the flagellar motor in Escherichia coli, demonstrating conclusively that the units have a duty ratio close to 1. Rotation of the bacterial flagellar motor is driven by multiple torque-generating units (stator elements). The torque-generating dynamics can be understood in terms of the “duty ratio” of the stator elements, that is, the fraction of time a stator element engages with the rotor during its mechanochemical cycle. The dependence of the limiting speed (zero-load speed) of the motor on the number of stator elements is the determining test of the duty ratio, which has been controversial experimentally and theoretically over the past decade. Here, we developed a method combining laser dark-field microscopy and optical trapping to resolve this controversy. We found that the zero-load speed is independent of the number of stator elements for the bacterial flagellar motor in Escherichia coli, demonstrating that these elements have a duty ratio close to 1.
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影响因子：
6.4
作者：
Tipping MJ;Delalez NJ;Lim R;Berry RM;Armitage JP
通讯作者：
Armitage JP
DOI：
10.1073/pnas.0509932103
发表时间：
2006-05-23
影响因子：
11.1
作者：
Reid, Stuart W.;Leake, Mark C.;Berry, Richard M.
通讯作者：
Berry, Richard M.
影响因子：
3.4
作者：
Jasmine A. Nirody;R. Berry;G. Oster
通讯作者：
Jasmine A. Nirody;R. Berry;G. Oster
影响因子：
3.4
作者：
Bai, Fan;Lo, Chien-Jung;Xing, Jianhua
通讯作者：
Xing, Jianhua
影响因子：
3.2
作者：
GUZMAN, LM;BELIN, D;BECKWITH, J
通讯作者：
BECKWITH, J