InterPro domain: IPR025657

This domain is found in a family of proteins present widely across bacteria. This family was named initially with reference to the Escherichia coli radC102 mutation which suggested that RadC was involved in repair of DNA lesions [ 1 ]. However, the relevant mutation has subsequently been shown to be in recG, where radC is in fact an allele of recG [ 2 ]. In addition, all attempts to characterise a radiation-related function for RadC in Streptococcus pneumoniae failed, suggesting that it is not involved in repair of DNA lesions, in recombination during transformation, in gene conversion, nor in mismatch repair [ 3 ].

The RadC-like domain belongs to the JAB superfamily of metalloproteins [ 4 ]. The domain shows fusions to an N-terminal Helix-hairpin-Helix (HhH) domain in most instances. Other domain combinations include fusions to the anti-restriction module ArdC, the DinG/RAD3-like superfamily II helicases and the DNAG-like primase. In some bacteria, closely related DinG/Rad3- like superfamily II helicases are fused to a 3'-5' exonuclease in the same position as the RadC-like JAB domain. These conserved domain associations lead to the hypothesis that the RadC-like JAB domains might function as a nuclease [ 5 ].

1. Tandem repeat recombination induced by replication fork defects in Escherichia coli requires a novel factor, RadC. Genetics 152, 5-13
2. radC102 of Escherichia coli is an allele of recG. J. Bacteriol. 182, 6287-91
3. RadC, a misleading name? J. Bacteriol. 190, 5729-32
4. Evolution of the deaminase fold and multiple origins of eukaryotic editing and mutagenic nucleic acid deaminases from bacterial toxin systems. Nucleic Acids Res. 39, 9473-97