The structure of the complete extracellular bacterial flagellum reveals the mechanism of flagellin incorporation.

ABSTRACT: The bacterial flagellum is essential for motility, adhesion and colonization in pathogens such as Salmonella enterica and Campylobacter jejuni. Its extracellular structure comprises the hook, hook-filament junction, filament and filament cap. Native structures of the hook-filament junction and the cap are lacking, and molecular mechanisms of cap-mediated filament assembly are largely uncharacterized. Here we use cryo-electron microscopy to resolve structures of the complete Salmonella extracellular flagellum including the pentameric FliD cap complex (3.7 Å) and the FlgKL hook-filament junction (2.9 Å), as well as the Campylobacter extracellular flagellum before filament assembly (6.5 Å). This, coupled with structure-guided mutagenesis and functional assays, reveals intermediates of filamen

SUBMITTER: Einenkel R 

PROVIDER: S-EPMC12221982 | biostudies-literature | 2025 Jul

REPOSITORIES: biostudies-literature