LIG3（DNA ligase 3），癌症关联基因，基因ID：3980，这个基因是DNA连接酶家族的一员。这个家族的每一个成员都编码一种蛋白质，对dna末端的连接进行催化，但它们在dna代谢中都有不同的作用。该基因编码的蛋白质参与切除修复，位于线粒体和细胞核中，翻译起始于上游起始密码子，允许向线粒体转运，翻译起始于下游起始密码子，允许向细胞核转运。此外，编码不同亚型的交替转录剪接变异体已经被描述出来。[由RefSeq提供，2008年7月]This gene is a member of the DNA ligase family. Each member of this family encodes a protein that catalyzes the joining of DNA ends but they each have a distinct role in DNA metabolism. The protein encoded by this gene is involved in excision repair and is located in both the mitochondria and nucleus， with translation initiation from the upstream start codon allowing for transport to the mitochondria and translation initiation from a downstream start codon allowing for transport to the nucleus. Additionally， alternate transcriptional splice variants， encoding different isoforms， have been characterized. [provided by RefSeq， Jul 2008]。