The B. subtilis helD allele rendered cells proficient in transformational recombination and moderately sensitive to methyl methanesulfonate when present in an otherwise Rec⁺ strain. The helD allele was introduced into rec-deficient strains representative of the  (recF strain),  (addA addB),  (recH),  (recU), and  (recS) epistatic groups. The helD mutation increased the sensitivity to DNA-damaging agents of addAB, recU, and recS cells, did not affect the survival of recH cells, and decreased the sensitivity of recF cells. helD also partially suppressed the DNA repair phenotype of other mutations classified within the  epistatic group, namely the recL, recO, and recR mutations. The helD allele marginally reduced plasmid transformation (three- to sevenfold) of mutations classified within the , , and  epistatic groups. Altogether, these data indicate that the loss of helicase IV might stabilize recombination repair intermediates formed in the absence of recFLOR and render recFLOR, addAB, and recH cells impaired in plasmid transformation.