Evolution and structural diversity of the MotAB stator: insights into the origins of bacterial flagellar motility.

ABSTRACT: The rotation of the bacterial flagellum is powered by the MotAB stator complex, which converts ion flux into torque. Despite its central role in flagellar function, the evolutionary origin and structural diversity of this system remain poorly understood. Here, we present the first comprehensive phylogenetic and structural characterization of MotAB and its closest non-flagellar homologs. We gathered homologs from 205 genomes across 27 bacterial phyla, estimated phylogenies, inferred ancestral sequences, and predicted structures for both extant and inferred ancestral proteins using AlphaFold. Our analyses characterized two structurally distinct groups: flagellar ion transporters (FIT) and generic ion transporters (GIT). FIT proteins are structurally conserved, including a characteristic squa

SUBMITTER: Puente-Lelievre C 

PROVIDER: S-EPMC12505986 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature