A plasmid-encoded inactive toxin-antitoxin system MtvT/MtvA regulates plasmid conjugative transfer and bacterial virulence in Pseudomonas aeruginosa.

ABSTRACT: Plasmid-encoded toxin-antitoxin (TA) systems are known for their role in plasmid maintenance via post-segregational killing. Here, we identified an inactive type II TA system, MtvT/MtvA (MtvTA), encoded on the conjugative plasmid pPAD8 from the clinical Pseudomonas aeruginosa strain PAD8. Despite its annotation as a toxin, MtvT exhibited no detectable toxicity in our assays. Interestingly, the deletion of the MtvTA significantly increased the transfer efficiency of pPAD8 from PAD8 to P. aeruginosa strain PAO1. Functional assays revealed that the MtvTA complex negatively regulates plasmid transfer by binding to the promoters of dot/icm system genes. In addition, pPAD8ΔmtvTA attenuated the pathogenicity of the host strain compared to pPAD8, highlighting a regulatory role for MtvTA in virulen

SUBMITTER: Li M 

PROVIDER: S-EPMC11826091 | biostudies-literature | 2025 Feb

REPOSITORIES: biostudies-literature