Structure of a type IV secretion system core complex encoded by multi-drug resistance F plasmids.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 35046412.
- Also identified by DOI 10.1038/s41467-022-28058-5 and PMC identifier 8770708.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Bacterial type IV secretion systems (T4SSs) are largely responsible for the proliferation of multi-drug resistance. We solved the structure of the outer-membrane core complex (OMCC<sub>F</sub>) of a T4SS encoded by a conjugative F plasmid at <3.0 Å resolution by cryoelectron microscopy. The OMCC<sub>F</sub> consists of a 13-fold symmetrical outer ring complex (ORC) built from 26 copies of TraK and TraV C-terminal domains, and a 17-fold symmetrical central cone (CC) composed of 17 copies of TraB β-barrels. Domains of TraV and TraB also bind the CC and ORC substructures, establishing that these proteins undergo an intraprotein symmetry alteration to accommodate the C13:C17 symmetry mismatch. We present evidence that other pED208-encoded factors stabilize the C13:C17 architecture and define the importance of TraK, TraV and TraB domains to T4SS<sub>F</sub> function. This work identifies OMCC<sub>F</sub> structural motifs of proposed importance for structural transitions associated with F plasmid dissemination and F pilus biogenesis.
Medical subject headings
- Drug Resistance, Multiple, Bacterial
- F Factor
- Type IV Secretion Systems