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Publication Abstract from PubMed

Bacterial conjugation is the fundamental process of unidirectional transfer of DNAs, often plasmid DNAs, from a donor cell to a recipient cell(1). It is the primary means by which antibiotic resistance genes spread among bacterial populations(2,3). In Gram-negative bacteria, conjugation is mediated by a large transport apparatus-the conjugative type IV secretion system (T4SS)-produced by the donor cell and embedded in both its outer and inner membranes. The T4SS also elaborates a long extracellular filament-the conjugative pilus-that is essential for DNA transfer(4,5). Here we present a high-resolution cryo-electron microscopy (cryo-EM) structure of a 2.8 megadalton T4SS complex composed of 92 polypeptides representing 8 of the 10 essential T4SS components involved in pilus biogenesis. We added the two remaining components to the structural model using co-evolution analysis of protein interfaces, to enable the reconstitution of the entire system including the pilus. This structure describes the exceptionally large protein-protein interaction network required to assemble the many components that constitute a T4SS and provides insights on the unique mechanism by which they elaborate pili.

Cryo-EM structure of a type IV secretion system.,Mace K, Vadakkepat AK, Redzej A, Lukoyanova N, Oomen C, Braun N, Ukleja M, Lu F, Costa TRD, Orlova EV, Baker D, Cong Q, Waksman G Nature. 2022 Jun 22. pii: 10.1038/s41586-022-04859-y. doi:, 10.1038/s41586-022-04859-y. PMID:35732732^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.