phosphoacceptor receiver (REC) domain of Rhodobacter capsulatus nitrogen regulatory protein C (NtrC) and similar NtrC family response regulators
NtrC family proteins are transcriptional regulators that have REC, AAA+ ATPase/sigma-54 interaction, and DNA-binding output domains. This subfamily of NtrC proteins include NtrC, also called nitrogen regulator I (NRI), from Rhodobacter capsulatus, Azospirillum brasilense, and Azorhizobium caulinodans. NtrC is part of the NtrB/NtrC two-component system that controls the expression of the nitrogen-regulated (ntr) genes in response to nitrogen limitation. The N-terminal REC domain of NtrC proteins regulate the activity of the protein and its phosphorylation controls the AAA+ domain oligomerization, while the central AAA+ domain participates in nucleotide binding, hydrolysis, oligomerization, and sigma54 interaction. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.
Feature 1: metal binding site [ion binding site], 3 residue positions
Conserved feature residue pattern:[ED] [ED] [ED]
Evidence:
Comment: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
Jiyao W et al.(2023). "The conserved domain database in 2023.",