Involved in DNA double-strand break (DSB) repair (PubMed:22135300). Acts probably with HerA to stimulate resection of the 5' strand and produce the long 3' single-strand that is required for RadA loading (By similarity). Processes linear dsDNA probes with 3' or 5' single-stranded overhangs or blunt ends (PubMed:22135300). Nuclease activity requires the presence of HerA. Homodimer (PubMed:22135300, PubMed:25447518). Forms a complex with HerA (PubMed:22135300, PubMed:25447518). Belongs to the NurA family.