Active Site

NAD-dependent DNA ligase, active site (IPR018239)

Short name: DNA_ligase_AS


DNA ligase (polydeoxyribonucleotide synthase) is the enzyme that joins two DNA fragments by catalyzing the formation of an internucleotide ester bond between phosphate and deoxyribose. It is active during DNA replication, DNA repair and DNA recombination. There are two forms of DNA ligase: one requires ATP (EC:, the other NAD (EC:

Bacterial DNA ligases are NAD-dependent. They are proteins of about 75 to 85 Kd whose sequence is well conserved. They also show similarity to yicF, an Escherichia coli hypothetical protein of 63 Kd [PMID: 1526462, PMID: 8390989].

This entry represents a conserved region that contains the KXDG motif required for adenylation of DNA ligases. The lysine residue is required for the adenylation step of the ligase and the aspartate is required for the de-adenylation step [PMID: 8760897, PMID: 1988940].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PROSITE patterns