A link between dimerization and autophosphorylation of the response regulator PhoB

Abstract

Background: Response regulator proteins within two-component signaling systems can autophosphorylate with small molecule phosphodonors. Results: Autophosphorylation kinetics of the response regulator PhoB exhibit multiple features indicative of positive cooperativity between active sites. Conclusion: PhoB autophosphorylation kinetics reflect formation of heterodimers (between phosphorylated and unphosphorylated monomers) with enhanced kinetics compared with monomers. Significance: Response regulator dimers with a single phosphoryl group may contribute to transcription regulation. © 2013 by The American Society for Biochemistry and Molecular Biology, Inc.