TOPRIM_recR: topoisomerase-primase (TOPRIM) nucleotidyl transferase/hydrolase domain of the type found in Escherichia coli RecR. RecR participates in the RecFOR pathway of homologous recombinational repair in prokaryotes. This pathway provides a single-stranded DNA molecule coated with RecA to allow invasion of a homologous molecule. The RecFOR system directs the loading of RecA onto gapped DNA coated with SSB protein. The TOPRIM domain has two conserved motifs, one of which centers at a conserved glutamate and the other one at two conserved aspartates (DxD). In RecR sequences this glutamate in the first turn of the TOPRIM domain is semiconserved, the DXD motif is not conserved.