CATH Classification

Domain Context

CATH Clusters

Superfamily DNA ligase/mRNA capping enzyme
Functional Family Putative DNA ligase 4

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 3L2P
External Links
Method X-RAY DIFFRACTION
Organism
Primary Citation
Human DNA Ligase III Recognizes DNA Ends by Dynamic Switching between Two DNA-Bound States.
Cotner-Gohara, E., Kim, I.K., Hammel, M., Tainer, J.A., Tomkinson, A.E., Ellenberger, T.
Biochemistry