The three-dimensional structure of the flagellar rotor from a clockwise-locked mutant of Salmonella enterica serovar typhimurium
The three-dimensional structure of the flagellar rotor from a clockwise-locked mutant of Salmonella enterica serovar typhimurium
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DOI：
10.1128/jb.00552-06
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发表时间：
2006-10-01
影响因子：
3.2
通讯作者：
DeRosier, David J.
中科院分区：
文献类型：
--
作者：
Thomas, Dennis R.;Francis, Noreen R.;DeRosier, David J.
鞭毛马达转子的电子冷冻显微照片的三维重建表明，单个 M 环的对称性在 24 倍到 26 倍之间变化，而包含两种马达/开关蛋白 FliM 和 FliN 的 C 环的对称性在 32 倍到 36 倍之间变化，两个环的对称性之间没有明显的相关性。其他研究的结果提供的证据表明，除了跨膜蛋白 FliF 之外，至少第三运动/开关蛋白 FliG 的某些部分有助于 M 环表面的增厚，但没有证据表明 FliG 的任何部分是否也有助于 C 环。在C环横截面的四个形态特征中，最接近M环的特征不具有C环其余部分的旋转对称性，而是具有M环的对称性。我们认为这个内部特征源自 FliG 的一个域。我们提出了一种假设的对接，其中 FliG 的 C 端运动结构域位于 C 环中，在那里它可以与 FliM 密切相互作用。
Three-dimensional reconstructions from electron cryomicrographs of the rotor of the flagellar motor reveal that the symmetry of individual M rings varies from 24-fold to 26-fold while that of the C rings, containing the two motor/switch proteins FliM and FliN, varies from 32-fold to 36-fold, with no apparent correlation between the symmetries of the two rings. Results from other studies provided evidence that, in addition to the transmembrane protein FliF, at least some part of the third motor/switch protein, FliG, contributes to a thickening on the face of the M ring, but there was no evidence as to whether or not any portion of FliG also contributes to the C ring. Of the four morphological features in the cross section of the C ring, the feature closest to the M ring is not present with the rotational symmetry of the rest of the C ring, but instead it has the symmetry of the M ring. We suggest that this inner feature arises from a domain of FliG. We present a hypothetical docking in which the C-terminal motor domain of FliG lies in the C ring, where it can interact intimately with FliM.