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Updated: Jun 27, 2025
06:56
Detection of Horizontal Gene Transfer Mediated by Natural Conjugative Plasmids in E. coli
Published on: March 24, 2023
5.4K
Discovering genetic determinants for cell-to-cell adhesion in two prevalent conjugative lactococcal plasmids
Guillermo Ortiz Charneco1, Philip Kelleher1, Andrius Buivydas1
1School of Microbiology & APC Microbiome Ireland, University College Cork, Western Road, Cork, Ireland.
Current Research in Microbial Sciences
|May 6, 2024
Summary
Researchers identified novel adhesins, TraAd and TrsAd, crucial for plasmid conjugation systems like pNP40 and pUC11B. These proteins mediate cell clumping and show reciprocal complementarity, enhancing DNA transfer efficiency between bacterial cells.
Area of Science:
- Microbiology
- Molecular Biology
- Genetics
Background:
- Plasmids pNP40 and pUC11B harbor prevalent but distinct conjugation systems.
- Recent characterization has detailed these systems.
- The specific adhesins mediating these conjugation processes were previously unidentified.
Purpose of the Study:
- To elucidate the putative adhesins of the pNP40 and pUC11B conjugation systems.
- To investigate the structural and functional roles of these adhesins in bacterial conjugation.
- To demonstrate the complementarity of these adhesins in mediating DNA transfer.
Main Methods:
- Sequence analysis to identify conserved components.
- Protein structure prediction using AlphaFold2.
- Functional assays involving expression of adhesins and plasmid conjugation experiments with mutant derivatives.
Main Results:
- The genes traAd and trsAd were identified as encoding the putative adhesins for pNP40 and pUC11B, respectively.
- TraAd and TrsAd, despite sequence divergence, share conserved peptidoglycan-hydrolase domains and structural similarities.
- Expression of TraAd and TrsAd induced cell clumping and demonstrated in trans reciprocal complementarity in conjugation.
Conclusions:
- TraAd and TrsAd are the key surface adhesins for the pNP40 and pUC11B conjugation systems.
- Structural similarities and functional complementarity highlight their conserved role in conjugation.
- These adhesins are essential for efficient plasmid DNA transfer between bacterial cells.
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