Evolutionary and functional divergence of Sfx, a plasmid-encoded H-NS homolog, underlies the regulation of IncX plasmid conjugation.

ABSTRACT: Conjugative plasmids are widespread among prokaryotes, highlighting their evolutionary success. Conjugation systems on most natural plasmids are repressed by default. The negative regulation of F-plasmid conjugation is partially mediated by the chromosomal nucleoid-structuring protein (H-NS). Recent bioinformatic analyses have revealed that plasmid-encoded H-NS homologs are widespread and exhibit high sequence diversity. However, the functional roles of most of these homologs and the selective forces driving their phylogenetic diversification remain unclear. In this study, we characterized the functionality and evolution of Sfx, a H-NS homolog encoded by the model IncX2 plasmid R6K. We demonstrate that Sfx, but not chromosomal H-NS, can repress R6K conjugation. Notably, we find evidence of

SUBMITTER: Wang A 

PROVIDER: S-EPMC11796372 | biostudies-literature | 2025 Feb

REPOSITORIES: biostudies-literature