DDB2（damage specific DNA binding protein 2），癌症关联基因，基因ID：1643，这个基因编码一种蛋白质，这是修复紫外线损伤的DNA所必需的。该蛋白是参与核苷酸切除修复的异二聚体蛋白复合物的较小亚单位，该复合物介导组蛋白h3和h4的泛素化，从而促进细胞对dna损伤的反应。这个亚单位似乎是DNA结合所必需的。该基因突变导致E组着色性干皮病，这是一种隐性疾病，其特征是对紫外线的敏感性增加，对皮肤癌的发展有高度的倾向，在某些情况下伴有神经异常。已经发现了两个编码不同亚型的转录变体。[由RefSeq提供，2014年7月]This gene encodes a protein that is necessary for the repair of ultraviolet light-damaged DNA. This protein is the smaller subunit of a heterodimeric protein complex that participates in nucleotide excision repair， and this complex mediates the ubiquitylation of histones H3 and H4， which facilitates the cellular response to DNA damage. This subunit appears to be required for DNA binding. Mutations in this gene cause xeroderma pigmentosum complementation group E， a recessive disease that is characterized by an increased sensitivity to UV light and a high predisposition for skin cancer development， in some cases accompanied by neurological abnormalities. Two trans。