MotI (DgrA) acts as a molecular clutch on the flagellar stator protein MotA in Bacillus subtilis.

ABSTRACT: Stator elements consisting of MotA₄MotB₂ complexes are anchored to the cell wall, extend through the cell membrane, and interact with FliG in the cytoplasmic C ring rotor of the flagellum. The cytoplasmic loop of MotA undergoes proton-driven conformational changes that drive flagellar rotation. Functional regulators inhibit motility by either disengaging or jamming the stator-rotor interaction. Here we show that the YcgR homolog MotI (formerly DgrA) of Bacillus subtilis inhibits motility like a molecular clutch that disengages MotA. MotI-inhibited flagella rotated freely by Brownian motion, and suppressor mutations in MotA that were immune to MotI inhibition were located two residues downstream of the critical force generation site. The 3D structure of MotI bou

SUBMITTER: Subramanian S 

PROVIDER: S-EPMC5754805 | biostudies-literature | 2017 Dec

REPOSITORIES: biostudies-literature