Structural bases for F plasmid conjugation and F pilus biogenesis in Escherichia coli.

ABSTRACT: Bacterial conjugation systems are members of the large type IV secretion system (T4SS) superfamily. Conjugative transfer of F plasmids residing in the Enterobacteriaceae was first reported in the 1940s, yet the architecture of F plasmid-encoded transfer channel and its physical relationship with the F pilus remain unknown. We visualized F-encoded structures in the native bacterial cell envelope by in situ cryoelectron tomography (CryoET). Remarkably, F plasmids encode four distinct structures, not just the translocation channel or channel-pilus complex predicted by prevailing models. The F1 structure is composed of distinct outer and inner membrane complexes and a connecting cylinder that together house the envelope-spanning translocation channel. The F2 structure is essentially the

SUBMITTER: Hu B 

PROVIDER: S-EPMC6628675 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature