The Limiting Speed of the Bacterial Flagellar Motor.
The Limiting Speed of the Bacterial Flagellar Motor.
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DOI：
10.1016/j.bpj.2016.07.003
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发表时间：
2015-05
影响因子：
3.4
通讯作者：
Jasmine A. Nirody;R. Berry;G. Oster
中科院分区：
文献类型：
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作者：
Jasmine A. Nirody;R. Berry;G. Oster
最近对细菌鞭毛马达的实验表明，这种驱动各种细菌物种运动的纳米机器的结构比以前认为的更具活力。具体而言，主动扭矩生成复合体（定子）的数量在施加的载荷之间变化。这一发现带来了审查的实验证据报告说，限制（零扭矩）的速度是独立的积极定子的数量。在这项研究中，我们提出，与以前的假设相反，电机的最大速度增加额外的定子招聘。这一结果源于我们的假设，即定子脱离电动机的一个显着的一部分，其机械化学循环在低负荷。我们表明，这一假设是一致的，与目前的实验证据在嵌合电机，以及与要求，通过弹性连杆驱动一个大的负载，一个进程电机必须有一个高的占空比。
Recent experiments on the bacterial flagellar motor have shown that the structure of this nanomachine, which drives locomotion in a wide range of bacterial species, is more dynamic than previously believed. Specifically, the number of active torque-generating complexes (stators) was shown to vary across applied loads. This finding brings under scrutiny the experimental evidence reporting that limiting (zero-torque) speed is independent of the number of active stators. In this study, we propose that, contrary to previous assumptions, the maximum speed of the motor increases as additional stators are recruited. This result arises from our assumption that stators disengage from the motor for a significant portion of their mechanochemical cycles at low loads. We show that this assumption is consistent with current experimental evidence in chimeric motors, as well as with the requirement that a processive motor driving a large load via an elastic linkage must have a high duty ratio.