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Updated: Jul 1, 2026
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Conjugative Mating Assays for Sequence-specific Analysis of Transfer Proteins Involved in Bacterial Conjugation
Published on: January 4, 2017
Structural basis for TrbM-enhanced conjugation and interbacterial killing in the RP4 plasmid
Lois Gordils-Valentin1,2, Jackson Belobrajdic1, Xuejun Zhu1,2
1Department of Chemical Engineering, Texas A&M University, College Station, TX 77843, USA.
Iscience
|June 30, 2026
Summary
The uncharacterized gene trbM enhances bacterial conjugation and interbacterial killing mediated by the type IV secretion system (T4SS). RP4-TrbM
Area of Science:
- Microbiology
- Molecular Biology
- Genetics
Background:
- Bacterial conjugation facilitates horizontal gene transfer and antibiotic resistance.
- Type IV secretion systems (T4SS) on conjugative plasmids like RP4 are key mediators.
- The uncharacterized gene trbM was previously found to enhance RP4-T4SS-mediated interbacterial killing.
Purpose of the Study:
- To characterize the RP4-TrbM protein and its structural features.
- To understand its role in enhancing bacterial conjugation and killing.
- To identify potential therapeutic targets for inhibiting T4SS-mediated processes.
Main Methods:
- Computational analyses to compare RP4-TrbM with known bacterial adhesins.
- Complementation assays using homologs from different plasmids (R751, R388, pKM101, R6K).
- Functional domain analysis of RP4-TrbM.
Main Results:
- RP4-TrbM shares similarities with known bacterial adhesins.
- Homologous proteins from R751, R388, and pKM101 could restore and enhance conjugation and killing in RP4-TrbM knockout strains.
- An essential functional domain within RP4-TrbM was identified and shown to retain activity when repositioned.
Conclusions:
- TrbM-like proteins play a significant role in boosting conjugation and T4SS-mediated killing.
- The identified functional domain is crucial for TrbM activity.
- TrbM-like proteins represent potential targets for developing inhibitors of T4SS-mediated processes.
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