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Updated: Jun 25, 2026

Conjugative Mating Assays for Sequence-specific Analysis of Transfer Proteins Involved in Bacterial Conjugation
Published on: January 4, 2017
The putative coupling protein TcpA interacts with other pCW3-encoded proteins to form an essential part of the
Jennifer A Steen1, Trudi L Bannam, Wee Lin Teng
1Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia.
Abstract:
Conjugative plasmids encode antibiotic resistance determinants or toxin genes in the anaerobic pathogen Clostridium perfringens. The paradigm conjugative plasmid in this bacterium is pCW3, a 47-kb tetracycline resistance plasmid that encodes the unique tcp transfer locus. The tcp locus consists of 11 genes, intP and tcpA-tcpJ, at least three of which, tcpA, tcpF, and tcpH, are essential for the conjugative transfer of pCW3. In this study we examined protein-protein interactions involving TcpA, the putative coupling protein. Use of a bacterial two-hybrid system identified interactions between TcpA and TcpC, TcpG, and TcpH. This analysis also demonstrated TcpA, TcpC, and TcpG self-interactions, which were confirmed by chemical cross-linking studies. Examination of a series of deletion and site-directed derivatives of TcpA identified the domains and motifs required for these interactions. Based on these results, we have constructed a model for this unique conjugative transfer apparatus.
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