The bacterial protein RecR is an important regulator in the RecFOR homologous recombination pathway during DNA repair. It acts with RecF and RecO forming a complex that facilitates the loading of RecA onto ssDNA. RecR is a zinc metalloprotein consisting of a N-terminal helix-hairpin-helix (HhH) motif, a middle region containing a zinc finger motif and a Toprim domain (Pfam:PF13662) and a C-terminal domain comprising a Walker B motif and a C-terminal helix [1,2]. This is the zinc finger motif, which consists of four strictly conserved cysteine residues which coordinate a zinc ion. This motif is the most conserved domain in RecR proteins and plays a structural role stabilizing the 3D structure of the protein [3].

1: RecOR complex including RecR N-N dimer and RecO monomer displays a high affinity for ssDNA. Tang Q, Gao P, Liu YP, Gao A, An XM, Liu S, Yan XX, Liang DC; Nucleic Acids Res. 2012;40:11115-11125. PMID:23019218

2: Crystal structure of RecR, a member of the RecFOR DNA-repair pathway, from Pseudomonas aeruginosa PAO1. Che S, Chen Y, Liang Y, Zhang Q, Bartlam M; Acta Crystallogr F Struct Biol Commun. 2018;74:222-230. PMID:29633970

3: Structural and functional characterization of Cys4 zinc finger motif in the recombination mediator protein RecR. Tang Q, Liu YP, Yan XX, Liang DC; DNA Repair (Amst). 2014;24:10-14. PMID:25460918