Crystal structure of nonphosphorylated receiver domain of the stress response regulator RcsB from Escherichia coli

Abstract

RcsB, the transcription-associated response regulator of the Rcs phosphorelay twocomponent signal transduction system, activates cell stress responses associated with desiccation, cell wall biosynthesis, cell division, virulence, biofilm formation, and antibiotic resistance in enteric bacterial pathogens. RcsB belongs to the FixJ/NarL family of transcriptional regulators, which are characterized by a highly conserved C-terminal DNA-binding domain. The N-terminal domain of RcsB belongs to the family of two-component receiver domains. This receiver domain contains the phosphoacceptor site and participates in RcsB dimer formation; it also contributes to dimer formation with other transcription factor partners. Here, we describe the crystal structure of the Escherichia coli RcsB receiver domain in its nonphosphorylated state. The structure reveals important molecular details of phosphorylation-independent dimerization of RcsB and has implication for the formation of heterodimers.

Involvement of Two-Component Signaling on Bacterial Motility and Biofilm Development

“…Regulation of flhD requires heterodimer formation of RcsB with the auxiliary protein RcsA, followed by binding to the conserved RcsAB box on the flhD promoter (40). Heterodimer formation can occur with a range of transcriptional regulators (41)(42)(43), often in a way that is unaffected by the phosphorylation state of RcsB (43,44) and instead favored at high concentrations of the protein (45). Altogether, the RcsCDB system has a myriad of functions in E. coli and other members of the family Enterobacteriaceae (9,(46)(47)(48)(49).…”

New Insights into the Non-orthodox Two Component Rcs Phosphorelay System

“…The C-terminal DNA-binding domain of RcsB, belonging to the FixJ/NarL family, forms a helix-turn-helix (HTH) DNA-binding motif ( Pristovsek et al, 2003 ). The N-terminal domain of RcsB, containing the phosphoacceptor site, belongs to the family of two-component receiver domains ( Filippova et al, 2016 ). This receiver domain participates in RcsB dimer formation and also contributes to dimer formation with other transcription factor partners.…”

“…In this situation, AcP, the intermediate of the Pta-AckA pathway, might provide the phosphoryl group for RcsB, ensuring a low level of RcsB phosphorylation ( Hu et al, 2013 ). Recently, Filippova et al (2016) solved the crystal structure of non-phosphorylated receiver domain of RcsB. They found that the RcsB receiver domain can exist as a dimer in solution ( Filippova et al, 2016 ).…”

“…Recently, Filippova et al (2016) solved the crystal structure of non-phosphorylated receiver domain of RcsB. They found that the RcsB receiver domain can exist as a dimer in solution ( Filippova et al, 2016 ). They suggested the non-phosphorylated and phosphorylated states of RcsB use a similar dimerization interface in the homodimer or heterodimers ( Filippova et al, 2016 ).…”

“…They found that the RcsB receiver domain can exist as a dimer in solution ( Filippova et al, 2016 ). They suggested the non-phosphorylated and phosphorylated states of RcsB use a similar dimerization interface in the homodimer or heterodimers ( Filippova et al, 2016 ). How phosphorylation affects the DNA binding ability and regulatory roles of RcsB is still not clear.…”