CATH Classification

Domain Context

CATH Clusters

Superfamily BRCT domain
Functional Family NAD-dependent DNA ligase LigA

Enzyme Information

6.5.1.2
DNA ligase (NAD(+)).
based on mapping to UniProt P26996
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)

P26996
DNLJ_THET8
Thermus thermophilus HB8
DNA ligase

PDB Structure

PDB 1L7B
External Links
Method SOLUTION NMR
Organism Escherichia
Primary Citation
Solution NMR Structure of the Brct Domain from Thermus Thermophilus DNA Ligase
Sahota, G., Dixon, B.L., Huang, Y.P., Aramini, J., Bhattacharya, A., Monleon, D., Swapna, G.V.T., Yin, C., Xiao, R., Anderson, S., Montelione, G.T., Tejero, R.
To be Published