Q16531

DDB1 also known as DDBA is the large subunit (p127) of the heterodimeric DNA damage-binding (DDB) complex while another protein (p48) forms the small subunit. DDB1 plays a crucial role in the cellular response to DNA damage, particularly damage caused by ultraviolet light. DDB1 is essential for the recognition and repair of DNA lesions, specifically cyclobutane pyrimidine dimers, which are formed when DNA is exposed to UV radiation. DDB1′s ability to bind to these damaged sites is vital for initiating the nucleotide excision repair pathway, thereby preventing mutations that could lead to skin cancer and other genetic disorders. Mutations in the DDB2 gene, which encodes the other subunit of the DDB complex, are linked to xeroderma pigmentosum group E, a condition characterized by extreme sensitivity to sunlight and a predisposition to skin malignancies.