The Escherichia coli metallo-regulator RcnR represses rcnA and rcnR transcription through binding on a shared operator site: Insights into regulatory specificity towards nickel and cobalt

► The promoters of the divergently transcribed rcnR and rcnA genes are convergent. ► rcnR controls its own transcription. ► Ni and Co and not other divalent cations are in vivo and in vitro effectors of RcnR activity.