A periplasmic polymer curves Vibrio cholerae and promotes pathogenesis

Pathogenic Vibrio cholerae remains a major human health concern. V. cholerae has a characteristic curved rod morphology, with a longer outer face and a shorter inner face. Previously, the mechanism and function of this curvature were unknown. Here we identify and characterize CrvA, the first curvature determinant in V. cholerae. CrvA self-assembles into filaments at the inner face of cell curvature. Unlike traditional cytoskeletons, CrvA localizes to the periplasm, and thus could be considered a periskeletal element. To quantify how curvature forms, we developed QuASAR (Quantitative Analysis of Sacculus Architecture Remodeling), which measures subcellular peptidoglycan dynamics. QuASAR reveals that CrvA asymmetrically patterns peptidoglycan insertion rather than removal, causing more material insertion into the outer face than the inner face. Furthermore, crvA is quorum regulated and CrvA-dependent curvature increases at high cell density. Finally, we demonstrate that CrvA promotes motility in hydrogels and confers an advantage in host colonization and pathogenesis.