Involved in DNA excision repair. Initiates repair by binding to damaged sites with various affinities, depending on the photoproduct and the transcriptional state of the region. Required for UV-induced CHEK1 phosphorylation and the recruitment of CEP164 to cyclobutane pyrimidine dimmers (CPD), sites of DNA damage after UV irradiation. Interacts with GPN1 and RPA1. Interacts (via N-terminus) with CEP164 upon UV irradiation. Interacts with HERC2. Expressed in various cell lines and in skin fibroblasts. Belongs to the XPA family. Note: This description may include information from UniProtKB.