phosphoacceptor receiver (REC) domain of photosynthetic apparatus regulatory protein RegA
Rhodobacter sphaeroides RegA, also called response regulator PrrA, is the DNA binding regulatory protein of a redox-responsive two-component regulatory system RegB/RegA that is involved in transactivating anaerobic expression of the photosynthetic apparatus. It contains a REC domain and a DNA-binding helix-turn-helix output domain. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.
Comment:also based on metal binding site of other family members
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
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