Fig. 4

Structure schematic of the bacterial flagellum. The bacterial flagellum structure consists of a basal body, a hook, and a filament. The basal structure is anchored in the outer and inner membranes. The hook is external to the cell, lying between the basal body and the filament. Filament consists of four domains, D0, D1, D2, and D3, in end-on view. Antibody responses tend to be targeted to the filament