phosphoacceptor receiver (REC) domain of type 4 fimbriae expression regulatory protein PilR and similar proteins
Pseudomonas aeruginosa PilR is the response regulator of the PilS/PilR two-component regulatory system (PilSR TCS) that acts in conjunction with sigma-54 to regulate the expression of type 4 pilus (T4P) major subunit PilA. In addition, the PilSR TCS regulates flagellum-dependent swimming motility and pilus-dependent twitching motility. PilR contains an N-terminal REC domain, a central sigma-54 interaction domain, and a C-terminal Fis-type helix-turn-helix DNA-binding domain. 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.",