Selective targeting of a histone-like silencer Sfx to the R6K conjugal transfer operon [RNA-Seq]

Conjugative DNA transfer is mediated by large membrane-spanning type IV secretion system (T4SS) complexes encoded by long plasmid operons (commonly called tra or vir). Conjugative IncX plasmids encode histone-like protein H-NS homolog as core gene. R6K, a prototype IncX plasmid, encodes its own H-NS homolog, Sfx, to repress the vir operon. Here, we show that, unlike other plasmid silencers that target promoters, Sfx cooperates with Rho factor to arrest transcription elongation. Our results show that Sfx mainly targets the R6K vir operon. Overall design: RNA-seq profiling of E. coli harboring plasmid R6K derivatives to detect the targets of histone-like silencer Sfx.