phosphoacceptor receiver (REC) domain of BaeR-like OmpR family response regulators
BaeR is part of the BaeSR two-component system that is involved in regulating genes that confer multidrug and metal resistance. In Salmonella, BaeSR induces AcrD and MdtABC drug efflux systems, increasing multidrug and metal resistance. In Escherichia coli, BaeR stimulates multidrug resistance via mdtABC (multidrug transporter ABC, formerly known as yegMNO) genes, which encode a resistance-nodulation-cell division (RND) drug efflux system. Members of this subfamily belong to the OmpR family of DNA-binding response regulators, which are characterized by a REC domain and a winged helix-turn-helix (wHTH) DNA-binding output effector domain. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.
Comment:signal transduction in two-component systems is mediated by metal ion dependent phosphorelay reactions between protein histidine kinases and phosphoaccepting receiver domains in response regulator proteins
Comment:for many receivers, Mg2+ is the preferred metal ion, but other divalent ions such as Mn2+ are also used
Jiyao W et al.(2023). "The conserved domain database in 2023.",