Variable symmetry in Salmonella typhimurium flagellar motors.
Variable symmetry in Salmonella typhimurium flagellar motors.
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DOI：
10.1016/s0006-3495(03)74877-2
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发表时间：
2003
影响因子：
3.4
通讯作者：
H. Young;Hong Dang;Yimin Lai;D. DeRosier;Shahid Khan
中科院分区：
文献类型：
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作者：
H. Young;Hong Dang;Yimin Lai;D. DeRosier;Shahid Khan
对在不动的大肠杆菌宿主中过量产生的鼠伤寒沙门氏菌鞭毛运动的转子复合体进行电子冷冻显微镜检查，揭示了细胞质环（C环）模块的亚基对称性的变化。发现亚基对称性范围为 31 至 38 的 C 环。他们在 34 到 35 之间的平均值周围形成高斯分布，与原生 C 环确定的数字相似。 C 环直径与亚基数量成比例，表明椭圆形亚基保持恒定的亚基间距。结合 M 环尺寸没有相应增加的证据，这一发现表明转子组装不需要 M 环和 C 环亚基之间严格的化学计量相互作用。讨论了对运动功能的影响。
Electron cryomicroscopy of rotor complexes of theSalmonella typhimuriumflagellar motor, overproduced in a nonmotileEscherichia colihost, has revealed a variation in subunit symmetry of the cytoplasmic ring (C ring) module. C rings with subunit symmetries ranging from 31 to 38 were found. They formed a Gaussian distribution around a mean between 34 and 35, a similar number to that determined for native C rings. C-ring diameter scaled with the number of subunits, indicating that the elliptical-shaped subunits maintained constant intersubunit spacing. Taken together with evidence that the M ring does not correspondingly increase in size, this finding indicates that rotor assembly does not require strict stoichiometric interactions between the M- and C-ring subunits. Implications for motor function are discussed.