A helicase with DNA-dependent ATPase activity (PubMed:8419285). Unwinds DNA duplexes with 3' to 5' polarity with respect to the bound strand. Initiates unwinding more efficiently from a nicked substrate than ds duplex DNA (PubMed:8419285). Involved in the post-incision events of nucleotide excision repair and methyl-directed mismatch repair, and probably also in repair of alkylated DNA (Probable). ATP + H2O = ADP + H(+) + phosphate Strongly sensitive to UV, ciprofloxacin (CFX), and azidothymidine (AZT) in single deletion mutants, radA-uvrD double deletions are more sensitive yet. Adding recF mutations almost completely suppresses AZT and partially suppresses UV and CFX sensitivity, suggesting RadA processes a class of intermediates that accumulate in uvrD mutants (PubMed:25484163). Belongs to the helicase family. UvrD subfamily.