Couples transcription and DNA repair by recognizing RNA polymerase (RNAP) stalled at DNA lesions. Mediates ATP-dependent release of RNAP and its truncated transcript from the DNA, and recruitment of nucleotide excision repair machinery to the damaged site. Can also dissociate RNAP that is blocked by low concentration of nucleoside triphosphates or by physical obstruction, such as bound proteins. In addition, can rescue arrested complexes by promoting forward translocation. Has ATPase activity, which is required for removal of stalled RNAP, but seems to lack helicase activity. May act through a translocase activity that rewinds upstream DNA, leading either to translocation or to release of RNAP when the enzyme active site cannot continue elongation. Monomer. Interacts with UvrA and RNAP. Consists of a compact arrangement of structured domains linked by long, flexible linkers. The N-terminal region interacts with UvrA, the central region interacts with RNAP, and the C-terminal DNA translocase region possesses ATPase activity. Activity is regulated by a conformational switch from a dormant closed state to an active open state upon substrate binding. In the N-terminal section; belongs to the UvrB family. In the C-terminal section; belongs to the helicase family. RecG subfamily.