Photolyase involved in the repair of UV-induced (6-4) lesions in DNA. Catalyzes the photoreactivation of (6-4) pyrimidine-pyrimidone photoproducts by using blue-light energy. Can repair (6-4) photoproducts in ssDNA as well as in dsDNA. (6-4) photoproduct (in DNA) = 2 pyrimidine residues (in DNA). Binds 1 FAD per subunit. Binds 6,7-dimethyl-8-ribityllumazine (DMRL) as antenna chromophore. Binds 1 [4Fe-4S] cluster per subunit. Cells lacking this gene show a strongly attenuated photoreactivation after treatment with UV-B irradiation. Belongs to the iron-sulfur bacterial cryptochrome/photolyase (FeS-BCP) family.