XPA protein is a key factor of the nucleotide excision repair
of various DNA lesions including UV-induced photoproducts. It is involved
in the damage recognition and the successive assembly of the protein complex
for the repair reaction. Patients with the defect in the XPA gene suffer from
the extreme sunlight sensitivity leading to erythema and skin cancers. The
structure of the central domain of the protein (1XPA) is shown together with
the music of the protein sequence.