The RecR protein plays a key role in the RecFOR pathway of recombination, which is necessary for the repair of ssDNA gaps. RecR from Deinococcus radiodurans has been overexpressed in Escherichia coli and crystallized at 297 K using polyethylene glycol 1000 as a precipitant. X-ray diffraction data to 2.90 A resolution have been collected at 100 K using Cu Kalpha X-rays from a mercury-soaked crystal. The crystal belongs to space group C222(1), with unit-cell parameters a = 106.96, b = 122.25, c = 156.01 A. The asymmetric unit contains four monomers of RecR, with a crystal volume per protein weight (V(M)) of 2.57 A(3) Da(-1) and a solvent content of 51.0%.