Regulation of conjugal transfer by Lrp and Dam methylation in plasmid R100

Abstract

The article explores how the conjugal transfer of the F-like plasmid R100 increases in frequency without DNA adenine methylation (Dam methylation). Dam methylation regulates the synthesis of FinP RNA, which affects plasmid transfer. The absence of the leucine-responsive regulatory protein (Lrp) decreases R100 transfer, indicating Lrp's role as an activator. These findings suggest that host-encoded regulators, similar to those in the Salmonella virulence plasmid pSLT, also influence R100. Both R100 and pSLT exhibit reduced transfer in rich media, indicating a regulatory similarity between them.