What is DNA damage-binding protein?

DNA damage-binding protein or UV-DDB is a protein complex that is responsible for repair of UV-damaged DNA. This complex is composed of two protein subunits, a large subunit DDB1 and a small subunit DDB2. When cells are exposed to UV radiation, DDB1 moves from the cytosol to the nucleus and binds to DDB2, thus forming the UV-DDB complex. This complex formation is highly favorable and it is demonstrated by UV-DDB's binding preference and high affinity to the UV lesions in the DNA. This complex functions in nucleotide excision repair, recognising UV-induced pyrimidine-pyrimidone photoproducts and cyclobutane pyrimidine dimers.