To distinguish between these alternatives , we first analyzed the expression of mgtA , pcgL , mgtC , and pmrC as an indirectly PhoP-regulated gene ( 21 , 43 ) in a phoP : : Tn10 strain , expressing PhoP from the IPTG-regu-lated plasmid pEG9014 .
PhoP binds to the promoter regions of pmrC genes .