Cross-talk between the Histidine Protein Kinase VanS and the Response Regulator PhoB: CHARACTERIZATION AND IDENTIFICATION OF A VanS DOMAIN THAT INHIBITS ACTIVATION OF PhoB

摘要: VanS is a two-component transmembrane sensory kinase that, together with its response regulator VanR, activates the expression of genes responsible for vancomycin resistance in Enterococcus faecium BM4147. In this report, we demonstrate that cytoplasmic domain (including residues Met95 to Ser384) capable high level activation (> 500 fold) Escherichia coli PhoB vivo absence signaling kinases PhoR, CreC (PhoM), or acetyl phosphate synthesis. vitro experiments carried out on purified proteins confirmed due efficient cross-talk between and PhoB, since phospho-VanS catalyzed transfer phosphoryl group approximately 90% 5 min at 1:4 VanS/PhoB stoichiometry. However, rate was least 100-fold slower than observed VanR. The used as reporter system identify peptide fragments interfering by VanS(Met95-Ser384), order an interaction domain. A library plasmids encoding VanS(Met95-Ser384) constructed using transposon mutagenesis, subpopulation these encoded peptides interfered VanS(Met95-Ser384). minimal size fragment (Met95-Ile174) shown be both necessary sufficient potent inhibition (85%) activation.