Putative single-stranded-DNA-specific exonuclease (By similarity). RecA thread formation during DNA double-strand break repair requires RecJ or AadAB. Cells lacking this gene show only slightly increased sensitivity to DNA-damaging agents. However, cells lacking RecJ and with a mutated AadAB enzyme were extremely sensitive to these agents, as sensitive as recA deletion strains. The doubly mutated strain shows 10-fold impaired growth in the absence of these agents. Belongs to the RecJ family.