CATH Classification

Domain Context

CATH Clusters

Superfamily BRCT domain
Functional Family DNA ligase

Enzyme Information

6.5.1.1
DNA ligase (ATP).
based on mapping to UniProt P49916
ATP + (deoxyribonucleotide)(n)-3'-hydroxyl + 5'-phospho- (deoxyribonucleotide)(m) = (deoxyribonucleotide)(n+m) + AMP + diphosphate.
-!- The enzyme 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 ATP, 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 6.5.1.2, EC 6.5.1.6 and EC 6.5.1.7.

UniProtKB Entries (1)

P49916
DNLI3_HUMAN
Homo sapiens
DNA ligase 3

PDB Structure

PDB 1IN1
External Links
Method SOLUTION NMR
Organism Escherichia
Primary Citation
Solution structure and backbone dynamics of the human DNA ligase IIIalpha BRCT domain
Krishnan, V.V., Thornton, K.H., Thelen, M.P., Cosman, M.
Biochemistry
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