Core-sheath coupling controls flagellar curvature and motility in <i>Leptospira</i>.

ABSTRACT: Spirochete pathogens are among the most invasive bacteria known, causing syphilis, Lyme disease, and leptospirosis. Their tissue penetration depends on periplasmic flagellar filaments that, unlike other bacterial flagella, are encased in a spirochete-specific multi-protein sheath and deform the cell body into motile waves. How these filaments achieve the mechanical properties needed for invasive motility has remained unclear. Here we determine complete atomic structures of the Leptospira endoflagellar filament, revealing an elaborate sheath of 9 to 12 distinct asymmetrically arranged proteins. We show that the flagellin variant forming the filament core determines sheath composition, producing curvatures ranging from ∼3.5 µm ^-1 to ∼5 µm ^-1 . The lower-curvature

SUBMITTER: Martin FS 

PROVIDER: S-EPMC12889604 | biostudies-literature | 2026 Feb

REPOSITORIES: biostudies-literature