Gordon, J.E. and Costa, Tiago and Patel, R.S. and Gonzalez-Rivera, C. and Sarkar, M.K. and Orlova, Elena and Waksman, Gabriel and Christie, P.J. (2017) Use of chimeric type IV secretion systems to define contributions of outer membrane subassemblies for contact-dependent translocation. Molecular Microbiology 105 (2), pp. 273-293. ISSN 0950-382X.
Abstract
Recent studies have shown that conjugation systems of Gram-negative bacteria are composed of distinct inner and outer membrane core complexes (IMCs and OMCCs, respectively). Here, we functionally characterized the OMCC, focusing first on a cap domain that forms a channel across the outer membrane. Strikingly, the OMCC caps of the Escherichia coli pKM101 Tra and Agrobacterium tumefaciens VirB/VirD4 systems are completely dispensable for substrate transfer, but required for formation of conjugative pili. The pKM101 OMCC cap and extended pilus also are dispensable for activation of a Pseudomonas aeruginosa type VI secretion system (T6SS). Chimeric conjugation systems composed of the IMCpKM101 joined to OMCCs from the A. tumefaciens VirB/VirD4, E. coli R388 Trw, and Bordetella pertussis Ptl systems support conjugative DNA transfer in E. coli and trigger P. aeruginosa T6SS killing, but not pilus production. The A. tumefaciens VirB/VirD4 OMCC, solved by transmission electron microscopy, adopts a cage structure similar to the pKM101 OMCC. Our findings establish that OMCCs are highly structurally and functionally conserved - but also intrinsically conformationally flexible - scaffolds for translocation channels. Furthermore, the OMCC cap and a pilus tip protein coregulate pilus extension but are not required for channel assembly or function.
Metadata
| Item Type: | Article |
|---|---|
| Keyword(s) / Subject(s): | Type IV secretion, Conjugation, Pilus, DNA translocation, antibiotic resistance |
| School: | Birkbeck Faculties and Schools > Faculty of Science > School of Natural Sciences |
| Depositing User: | Administrator |
| Date Deposited: | 09 May 2017 09:23 |
| Last Modified: | 02 Aug 2023 17:32 |
| URI: | https://eprints.bbk.ac.uk/id/eprint/18684 |
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