CATH Classification

Domain Context

CATH Clusters

Superfamily 3.30.1490.70
Functional Family NAD-dependent DNA ligase LigA

Enzyme Information

6.5.1.2
DNA ligase (NAD(+)).
based on mapping to UniProt P15042
NAD(+) + (deoxyribonucleotide)(n)-3'-hydroxyl + 5'-phospho- (deoxyribonucleotide)(m) = (deoxyribonucleotide)(n+m) + AMP + beta- nicotinamide D-nucleotide.
-!- The enzyme, typically found in bacteria, catalyzes the ligation of DNA strands with 3'-hydroxyl and 5'-phosphate termini, forming a phosphodiester and sealing certain types of single-strand breaks in duplex DNA. -!- Catalysis occurs by a three-step mechanism, starting with the activation of the enzyme by NAD(+), forming a phosphoramide bond between adenylate and a lysine residue. -!- The adenylate group is then transferred to the 5'-phosphate terminus of the substrate, forming the capped structure 5'-(5'-diphosphoadenosine)-(DNA). -!- Finally, the enzyme catalyzes a nucleophilic attack of the 3'-OH terminus on the capped terminus, which results in formation of the phosphodiester bond and release of the adenylate. -!- RNA can also act as substrate, to some extent. -!- Cf. EC 6.5.1.1, EC 6.5.1.6, and EC 6.5.1.7.

UniProtKB Entries (1)

P15042
DNLJ_ECOLI
Escherichia coli K-12
DNA ligase

PDB Structure

PDB 2OWO
External Links
Method X-RAY DIFFRACTION
Organism Escherichia
Primary Citation
Last Stop on the Road to Repair: Structure of E. coli DNA Ligase Bound to Nicked DNA-Adenylate.
Nandakumar, J., Nair, P.A., Shuman, S.
Mol.Cell