8XP1

Cryo-EM structure of the protomers of the C ring in the CW state

これはPDB形式変換不可エントリーです。

8XP1 の概要

• エントリーDOI: 10.2210/pdb8xp1/pdb
• 関連するPDBエントリー: 8WIW
• EMDBエントリー: 37570 38547
• 分子名称: Flagellar motor switch protein FliN, Flagellar M-ring protein, Flagellar motor switch protein FliM, ... (5 entities in total)
• 機能のキーワード: flagellum, flagellar motor, c ring, chey, motor protein
• 由来する生物種: Salmonella enterica subsp. enterica serovar Typhimurium str. LT2; 詳細
• タンパク質・核酸の鎖数: 21
• 化学式量合計: 584011.95

構造登録者

Tan, J.X.,Zhang, L.,Zhou, Y.,Zhu, Y.Q. (登録日: 2024-01-02, 公開日: 2024-09-04, 最終更新日: 2025-03-26)

主引用文献

Tan, J.,Zhang, L.,Zhou, X.,Han, S.,Zhou, Y.,Zhu, Y.
Structural basis of the bacterial flagellar motor rotational switching.
Cell Res., 34:788-801, 2024

PubMed Abstract: The bacterial flagellar motor is a huge bidirectional rotary nanomachine that drives rotation of the flagellum for bacterial motility. The cytoplasmic C ring of the flagellar motor functions as the switch complex for the rotational direction switching from counterclockwise to clockwise. However, the structural basis of the rotational switching and how the C ring is assembled have long remained elusive. Here, we present two high-resolution cryo-electron microscopy structures of the C ring-containing flagellar basal body-hook complex from Salmonella Typhimurium, which are in the default counterclockwise state and in a constitutively active CheY mutant-induced clockwise state, respectively. In both complexes, the C ring consists of four subrings, but is in two different conformations. The CheY proteins are bound into an open groove between two adjacent protomers on the surface of the middle subring of the C ring and interact with the FliG and FliM subunits. The binding of the CheY protein induces a significant upward shift of the C ring towards the MS ring and inward movements of its protomers towards the motor center, which eventually remodels the structures of the FliG subunits and reverses the orientations and surface electrostatic potential of the α helices to trigger the counterclockwise-to-clockwise rotational switching. The conformational changes of the FliG subunits reveal that the stator units on the motor require a relocation process in the inner membrane during the rotational switching. This study provides unprecedented molecular insights into the rotational switching mechanism and a detailed overall structural view of the bacterial flagellar motors.

PubMed: 39179739
DOI: 10.1038/s41422-024-01017-z

実験手法

ELECTRON MICROSCOPY (4.4 Å)