Photolyase involved in the repair of UV radiation-induced DNA damage. By using blue-light energy, catalyzes the photoreactivation of cyclobutane pyrimidine dimers (CPDs), which are formed between adjacent bases on the same DNA strand upon exposure to ultraviolet radiation. Can repair CPD lesions in ssDNA as well as in dsDNA. cyclobutadipyrimidine (in DNA) = 2 pyrimidine residues (in DNA). Binds 1 FAD per subunit. Binds 1 5,10-methenyltetrahydrofolate (MTHF) per subunit, that serves as photoantenna. Cells lacking this gene show an attenuated photoreactivation after treatment with UV-B irradiation. Belongs to the DNA photolyase class-3 family.