The PAS domain of the polarly localized histidine kinase FlrB in <i>Vibrio cholerae</i> controls class III flagellar transcription and contributes to intestinal colonization.

ABSTRACT: Vibrio cholerae motility is mediated by a single polar flagellum, composed of four flagellin subunits (FlaABCD) in the filament; however, only FlaA is required for motility. Class III flagellar genes, which include flaA, are controlled by the two-component FlrBC system. FlrB is a histidine kinase that phosphorylates FlrC, which activates Class III promoters. The signal(s) that control phosphotransfer between FlrB and FlrC are unknown. A V. cholerae strain lacking the "non-essential" flagellin genes (ΔflaCEDB) is non-motile. Selection for spontaneous motile strains resulted in mutations localized to a Per-Arnt-Sim (PAS) domain in the FlrB N-terminus, including the mutation L36F. The X-ray crystal structure of FlrB revealed an asymmetric dimer with a unique fold o

SUBMITTER: Stanton V 

PROVIDER: S-EPMC12607845 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature