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ENZYME entry: EC

Accepted Name
DNA ligase (ATP or NAD(+))
Reaction catalysed
  • ATP + (deoxyribonucleotide)n-3'-hydroxyl + 5'-phospho-(deoxyribonucleotide)m <=> (deoxyribonucleotide)n+m + AMP + diphosphate
  • NAD(+) + (deoxyribonucleotide)n-3'-hydroxyl + 5'-phospho-(deoxyribonucleotide)m <=> (deoxyribonucleotide)n+m + AMP + beta-nicotinamide D-nucleotide
  • The enzymes from the archaea Thermococcus fumicolans and Thermococcus onnurineus show high activity with either ATP or NAD(+), and significantly lower activity with TTP, GTP, and CTP.
  • 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 or 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.
  • Different from EC, EC and EC
PRIAM enzyme-specific profiles6.5.1.6
KEGG Ligand Database for Enzyme Nomenclature6.5.1.6
IUBMB Enzyme Nomenclature6.5.1.6
MEDLINEFind literature relating to
Rhea expert-curated reactions6.5.1.6

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