Electrostatic interactions between rotor and stator in the bacterial flagellar motor.
Electrostatic interactions between rotor and stator in the bacterial flagellar motor.
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DOI：
10.1073/pnas.95.11.6436
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发表时间：
1998-05
影响因子：
11.1
通讯作者：
Jiadong Zhou;S. A. Lloyd;D. Blair
中科院分区：
文献类型：
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作者：
Jiadong Zhou;S. A. Lloyd;D. Blair
细菌鞭毛马达旋转，从质子或钠离子（在某些物种中）的膜梯度获得动力。鞭毛马达中的扭矩产生必须涉及转子组件和定子组件之间的相互作用。转子和定子之间相互作用的部位尚未确定。转子蛋白FliG和定子蛋白MotA的突变研究表明，这两种蛋白质都含有电动机旋转所必需的带电残基。这表明，功能上重要的静电相互作用可能发生在转子和定子之间。为了测试这一建议，我们研究了双突变体的转子蛋白FliG和定子蛋白MotA的带电残基取代。FliG突变与MotA突变的几种组合表现出强烈的协同作用，而其他组合则表现出强烈的抑制作用，这种模式表明FliG的功能重要的带电残基与MotA的残基相互作用。这些结果确定了一个功能上重要的网站之间的相互作用的转子和定子，并建议在转子-定子界面的静电相互作用的假设。
Bacterial flagellar motors rotate, obtaining power from the membrane gradient of protons or, in some species, sodium ions. Torque generation in the flagellar motor must involve interactions between components of the rotor and components of the stator. Sites of interaction between the rotor and stator have not been identified. Mutational studies of the rotor protein FliG and the stator protein MotA showed that both proteins contain charged residues essential for motor rotation. This suggests that functionally important electrostatic interactions might occur between the rotor and stator. To test this proposal, we examined double mutants with charged-residue substitutions in both the rotor protein FliG and the stator protein MotA. Several combinations of FliG mutations with MotA mutations exhibited strong synergism, whereas others showed strong suppression, in a pattern that indicates that the functionally important charged residues of FliG interact with those of MotA. These results identify a functionally important site of interaction between the rotor and stator and suggest a hypothesis for electrostatic interactions at the rotor-stator interface.