ATP Dependent DNA ligase II (LIG2)

The LIG3 cDNA encodes a polypeptide of 862 amino acids, whose sequence is more closely related to those of the DNA ligases encoded by poxviruses than to replicative DNA ligases, such as human DNA ligase I. Amino acid sequencing studies indicated that these enzymes are encoded by the same gene.

Downregulation of LIG3 impaired removal of ultraviolet (UV)-induced lesions and rejoining of UV-induced nicks in chromosomal DNA. Moreover, XRCC1-LIG3 and polymerase-delta (POLD1) interacted and colocalized with NER components in a UV-specific manner throughout interphase. In contrast, recruitment of LIG1 and polymerase-epsilon (POLE) to UV-irradiated sites was only observed in proliferating cells.