Insight into structural remodeling of the FlhA ring responsible for bacterial flagellar type III protein export.

ABSTRACT: The bacterial flagellum is a supramolecular motility machine. Flagellar assembly begins with the basal body, followed by the hook and finally the filament. A carboxyl-terminal cytoplasmic domain of FlhA (FlhA_C) forms a nonameric ring structure in the flagellar type III protein export apparatus and coordinates flagellar protein export with assembly. However, the mechanism of this process remains unknown. We report that a flexible linker of FlhA_C (FlhA_L) is required not only for FlhA_C ring formation but also for substrate specificity switching of the protein export apparatus from the hook protein to the filament protein upon completion of the hook structure. FlhA_L was required for cooperative ring formation of FlhA_C. Alanine s

SUBMITTER: Terahara N 

PROVIDER: S-EPMC5916509 | biostudies-literature | 2018 Apr

REPOSITORIES: biostudies-literature