The flagellar motor of <i>Vibrio alginolyticus</i> undergoes major structural remodeling during rotational switching.

ABSTRACT: The bacterial flagellar motor switches rotational direction between counterclockwise (CCW) and clockwise (CW) to direct the migration of the cell. The cytoplasmic ring (C-ring) of the motor, which is composed of FliG, FliM, and FliN, is known for controlling the rotational sense of the flagellum. However, the mechanism underlying rotational switching remains elusive. Here, we deployed cryo-electron tomography to visualize the C-ring in two rotational biased mutants in Vibrio alginolyticus. We determined the C-ring molecular architectures, providing novel insights into the mechanism of rotational switching. We report that the C-ring maintained 34-fold symmetry in both rotational senses, and the protein composition remained constant. The two structures show FliG conformational changes

SUBMITTER: Carroll BL 

PROVIDER: S-EPMC7505661 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature