Bacterial protein present in a flagellum, a long hair-like cell surface appendage. The flagellar apparatus consists of the flagellar filament made of polymerized flagellin, the hook-like structure near the cell surface and a system of rings embedded in the cell enveloppe (the basal body or flagellar motor). The basal body and the hook anchor the whip-like filament to the cell surface. The flagellum is a rotating structure with switches propels the cell through a liquid medium.

› Cellular component

› bacterial-type flagellum [ GO:0009288 ]