Functional synergy of heteropentameric B subunits underlies virulence in a Salmonella A2B5 toxin.

ABSTRACT: AB5-type toxins are critical virulence factors in bacterial pathogenesis. Despite the identification of various B subunits in AB5 toxins across different pathogens, their assembly mechanisms and biological significance remain poorly understood. In this study, we identified and characterized a typhoid toxin-like A2B5 toxin, designated diarizonae toxin (DiaT), as a key virulence factor in Salmonella diarizonae. The DiaT genomic islet encodes two distinct B subunits, PltBd1 and PltBd2, which exhibit unique functional roles. Through genetic and functional analyses, we demonstrate that the heteropentameric assembly of PltBd1 and PltBd2 is essential for cytotoxicity, with our data suggesting PltBd1 facilitates toxin secretion and PltBd2 mediates host cell targeting. Cryo-EM structural analysis o

SUBMITTER: Wang D 

PROVIDER: S-EPMC12629460 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature