該基因編碼的蛋白質是一種DNA連接酶，在ATP依賴的反應中連接雙鏈聚脫氧核苷酸中的單鏈斷裂該蛋白是v（d）j重組和dna雙鏈斷裂（dsb）修復的關鍵。該蛋白與X射線修復交叉互補蛋白4（XRCC4）形成復合物，并進一步與DNA依賴性蛋白激酶（DNA-PK）相互作用已知NHEJ需要XRCC4和DNA-PK。該蛋白與XRCC4形成的配合物的晶體結構已被解析。該基因缺陷是LIG4綜合征的病因另外，還觀察到編碼相同蛋白質的剪接轉錄變體[由RefSeq提供，2008年7月]
The protein encoded by this gene is a DNA ligase that joins single-strand breaks in a double-stranded polydeoxynucleotide in an ATP-dependent reaction. This protein is essential for V(D)J recombination and DNA double-strand break (DSB) repair through nonhomologous end joining (NHEJ). This protein forms a complex with the X-ray repair cross complementing protein 4 (XRCC4), and further interacts with the DNA-dependent protein kinase (DNA-PK). Both XRCC4 and DNA-PK are known to be required for NHEJ. The crystal structure of the complex formed by this protein and XRCC4 has been resolved. Defects in this gene are the cause of LIG4 syndrome. Alternatively spliced transcript variants encoding the same protein have been observed. [provided by RefSeq, Jul 2008]