Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (NC-IUBMB)

Enzyme Nomenclature. Recommendations

Contents EC 6.1.1.1 - EC 6.5.1.4

EC 6. Ligases

EC 6.1 Forming Carbon-Oxygen Bonds

EC 6.1.1 Ligases Forming Aminoacyl-tRNA and Related Compounds

EC 6.1.1.1 tyrosine—tRNA ligase
EC 6.1.1.2 tryptophan—tRNA ligase
EC 6.1.1.3 threonine—tRNA ligase
EC 6.1.1.4 leucine—tRNA ligase
EC 6.1.1.5 isoleucine—tRNA ligase
EC 6.1.1.6 lysine—tRNA ligase
EC 6.1.1.7 alanine—tRNA ligase
EC 6.1.1.8 deleted
EC 6.1.1.9 valine—tRNA ligase
EC 6.1.1.10 methionine—tRNA ligase
EC 6.1.1.11 serine—tRNA ligase
EC 6.1.1.12 aspartate—tRNA ligase
EC 6.1.1.13 D-alanine-poly(phosphoribitol) ligase
EC 6.1.1.14 glycine—tRNA ligase
EC 6.1.1.15 proline—tRNA ligase
EC 6.1.1.16 cysteine—tRNA ligase
EC 6.1.1.17 glutamate—tRNA ligase
EC 6.1.1.18 glutamine—tRNA ligase
EC 6.1.1.19 arginine—tRNA ligase
EC 6.1.1.20 phenylalanine—tRNA ligase
EC 6.1.1.21 histidine—tRNA ligase
EC 6.1.1.22 asparagine—tRNA ligase
EC 6.1.1.23 aspartate—tRNAAsn ligase
EC 6.1.1.24 glutamate—tRNAGln ligase
EC 6.1.1.25 deleted
EC 6.1.1.26 pyrrolysine—tRNAPyl ligase
EC 6.1.1.27 O-phosphoserine—tRNA ligase
EC 6.1.1.28 deleted

EC 6.1.2 Acid—Alcohol Ligases (ester synthases)

EC 6.1.2.1 D-alanine—(R)-lactate ligase
EC 6.1.2.2 nebramycin 5' synthase

EC 6.2 Forming Carbon-Sulfur Bonds

EC 6.2.1 Acid-Thiol Ligases

EC 6.2.1.1 acetate—CoA ligase
EC 6.2.1.2 butyrate—CoA ligase
EC 6.2.1.3 long-chain-fatty-acid—CoA ligase
EC 6.2.1.4 succinate—CoA ligase (GDP-forming)
EC 6.2.1.5 succinate—CoA ligase (ADP-forming)
EC 6.2.1.6 glutarate—CoA ligase
EC 6.2.1.7 cholate—CoA ligase
EC 6.2.1.8 oxalate—CoA ligase
EC 6.2.1.9 malate—CoA ligase
EC 6.2.1.10 acid—CoA ligase (GDP-forming)
EC 6.2.1.11 biotin—CoA ligase
EC 6.2.1.12 4-coumarate—CoA ligase
EC 6.2.1.13 acetate—CoA ligase (ADP-forming)
EC 6.2.1.14 6-carboxyhexanoate—CoA ligase
EC 6.2.1.15 arachidonate—CoA ligase
EC 6.2.1.16 acetoacetate—CoA ligase
EC 6.2.1.17 propionate—CoA ligase
EC 6.2.1.18 citrate—CoA ligase
EC 6.2.1.19 long-chain-fatty-acid—protein ligase
EC 6.2.1.20 long-chain-fatty-acid—[acyl-carrier-protein] ligase
EC 6.2.1.21 covered by EC 6.2.1.30
EC 6.2.1.22 [citrate (pro-3S)-lyase] ligase
EC 6.2.1.23 dicarboxylate—CoA ligase
EC 6.2.1.24 phytanate—CoA ligase
EC 6.2.1.25 benzoate—CoA ligase
EC 6.2.1.26 o-succinylbenzoate—CoA ligase
EC 6.2.1.27 4-hydroxybenzoate—CoA ligase
EC 6.2.1.28 3α,7α-dihydroxy-5β-cholestanate—CoA ligase
EC 6.2.1.29 deleted now EC 6.2.1.7
EC 6.2.1.30 phenylacetate—CoA ligase
EC 6.2.1.31 2-furoate—CoA ligase
EC 6.2.1.32 anthranilate—CoA ligase
EC 6.2.1.33 4-chlorobenzoate—CoA ligase
EC 6.2.1.34 trans-feruloyl-CoA synthase
EC 6.2.1.35 ACP-SH:acetate ligase
EC 6.2.1.36 3-hydroxypropionyl-CoA synthase
EC 6.2.1.37 3-hydroxybenzoate—CoA ligase
EC 6.2.1.38 (2,2,3-trimethyl-5-oxocyclopent-3-enyl)acetyl-CoA synthase
EC 6.2.1.39 [butirosin acyl-carrier protein]—L-glutamate ligase
EC 6.2.1.40 4-hydroxybutyrate—CoA ligase
EC 6.2.1.41 3-[(3aS,4S,7aS)-7a-methyl-1,5-dioxo-octahydro-1H-inden-4-yl]propanoate—CoA ligase
EC 6.2.1.42 3-oxocholest-4-en-26-oate—CoA ligase
EC 6.2.1.43 2-hydroxy-7-methoxy-5-methyl-1-naphthoate—CoA ligase
EC 6.2.1.44 3-(methylthio)propionyl—CoA ligase
EC 6.2.1.45 E1 ubiquitin-activating enzyme
EC 6.2.1.46 L-allo-isoleucine:holo-[CmaA peptidyl-carrier protein] ligase
EC 6.2.1.47 medium-chain-fatty-acid—[acyl-carrier-protein] ligase
EC 6.2.1.48 carnitine-CoA ligase
EC 6.2.1.49 long-chain fatty acid adenylyltransferase FadD28

EC 6.3 Forming Carbon-Nitrogen Bonds

EC 6.3.1 Acid-Ammonia (or Amine) Ligases (Amide Synthases)

EC 6.3.1.1 aspartate—ammonia ligase
EC 6.3.1.2 glutamine synthetase
EC 6.3.1.3 now EC 6.3.4.13
EC 6.3.1.4 aspartate—ammonia ligase (ADP-forming)
EC 6.3.1.5 NAD+ synthase
EC 6.3.1.6 glutamate—ethylamine ligase
EC 6.3.1.7 4-methyleneglutamate—ammonia ligase
EC 6.3.1.8 glutathionylspermidine synthase
EC 6.3.1.9 trypanothione synthase
EC 6.3.1.10 adenosylcobinamide-phosphate synthase
EC 6.3.1.11 glutamate—putrescine ligase
EC 6.3.1.12 D-aspartate ligase)
EC 6.3.1.13 L-cysteine:1D-myo-inositol 2-amino-2-deoxy-α-D-glucopyranoside ligase
EC 6.3.1.14 diphthine—ammonia ligase
EC 6.3.1.15 8-demethylnovobiocic acid synthase
EC 6.3.1.16 transferred, misclassified, see EC 6.3.3.6
EC 6.3.1.17 β-citrylglutamate synthase
EC 6.3.1.18 γ-glutamylanilide synthase

EC 6.3.1.19 prokaryotic ubiquitin-like protein ligase
EC 6.3.1.20 lipoate—protein ligase

EC 6.3.2 Acid—Amino-Acid Ligases (Peptide Synthases)

EC 6.3.2.1 pantoate—β-alanine ligase (AMP-forming)
EC 6.3.2.2 glutamate—cysteine ligase
EC 6.3.2.3 glutathione synthase
EC 6.3.2.4 D-alanine—D-alanine ligase
EC 6.3.2.5 phosphopantothenate—cysteine ligase (CTP)
EC 6.3.2.6 phosphoribosylaminoimidazolesuccinocarboxamide synthase
EC 6.3.2.7 UDP-N-acetylmuramoyl-L-alanyl-D-glutamate—L-lysine ligase
EC 6.3.2.8 UDP-N-acetylmuramate—L-alanine ligase
EC 6.3.2.9 UDP-N-acetylmuramoylalanine—D-glutamate ligase
EC 6.3.2.10 UDP-N-acetylmuramoylalanyl-tripeptide—D-alanyl-D-alanine ligase
EC 6.3.2.11 carnosine synthase
EC 6.3.2.12 dihydrofolate synthase
EC 6.3.2.13 UDP-N-acetylmuramoyl-L-alanyl-D-glutamate—2,6-diaminopimelate ligase
EC 6.3.2.14 enterobactin synthase
EC 6.3.2.15 deleted, due to EC 6.3.2.10
EC 6.3.2.16 D-alanine—alanyl-poly(glycerolphosphate) ligase
EC 6.3.2.17 tetrahydrofolate synthase
EC 6.3.2.18 γ-glutamylhistamine synthase
EC 6.3.2.19 deleted, now covered by EC 6.2.1.45, EC 2.3.2.23 and EC 6.3.2.20 indoleacetate—lysine synthetase
EC 6.3.2.21 deleted, now covered by EC 6.2.1.45 and EC 2.3.2.27
EC 6.3.2.28 transferred now EC 6.3.2.49
EC 6.3.2.22 deleted now EC 6.3.1.14
EC 6.3.2.23 homoglutathione synthase
EC 6.3.2.24 tyrosine—arginine ligase
EC 6.3.2.25 tubulin—tyrosine ligase
EC 6.3.2.26 N-(5-amino-5-carboxypentanoyl)-L-cysteinyl-D-valine synthase
EC 6.3.2.27 deleted now covered by EC 6.3.2.38 and EC 6.3.2.39
EC 6.3.2.28 L-amino-acid α-ligase
EC 6.3.2.29 cyanophycin synthase (L-aspartate-adding)
EC 6.3.2.30 cyanophycin synthase (L-arginine-adding)
EC 6.3.2.31 coenzyme F420-0:L-glutamate ligase
EC 6.3.2.32 coenzyme γ-F420-2:α-L-glutamate ligase
EC 6.3.2.33 tetrahydrosarcinapterin synthase
EC 6.3.2.34 coenzyme F420-1:γ-L-glutamate ligase
EC 6.3.2.35 D-alanine—D-serine ligase
EC 6.3.2.36 4-phosphopantoate—β-alanine ligase
EC 6.3.2.37 UDP-N-acetylmuramoyl-L-alanyl-D-glutamate—D-lysine ligase
EC 6.3.2.38 N2-citryl-N6-acetyl-N6-hydroxylysine synthase
EC 6.3.2.39 aerobactin synthase
EC 6.3.2.40 cyclopeptine synthase
EC 6.3.2.41 N-acetylaspartylglutamate synthase
EC 6.3.2.42 N-acetylaspartylglutamylglutamate synthase
EC 6.3.2.43 [lysine-biosynthesis-protein LysW]—L-2-aminoadipate ligase
EC 6.3.2.44 pantoate—β-alanine ligase (ADP-forming)
EC 6.3.2.45 UDP-N-acetylmuramate L-alanyl-γ-D-glutamyl-meso-2,6-diaminoheptanedioate ligase
EC 6.3.2.46 fumarate—(S)-2,3-diaminopropanoate ligase
EC 6.3.2.47 dapdiamide synthase
EC 6.3.2.48 L-arginine-specific L-amino acid ligase
EC 6.3.2.49 L-alanine-L-anticapsin ligase
EC 6.3.2.50 tenuazonic acid synthetase
EC 6.3.2.51 phosphopantothenate—cysteine ligase (ATP)

EC 6.3.3 Cyclo-Ligases

EC 6.3.3.1 phosphoribosylformylglycinamidine cyclo-ligase
EC 6.3.3.2 5-formyltetrahydrofolate cyclo-ligase
EC 6.3.3.3 dethiobiotin synthase
EC 6.3.3.4 (carboxyethyl)arginine β-lactam-synthase
EC 6.3.3.5 O-ureido-D-serine cyclo-ligase
EC 6.3.3.6 carbapenam-3-carboxylate synthase
EC 6.3.3.7 Ni-sirohydrochlorin a,c-diamide reductive cyclase

EC 6.3.4 Other Carbon-Nitrogen Ligases

EC 6.3.4.1 transferred now included in EC 6.3.5.2
EC 6.3.4.2 CTP synthase (glutamine hydrolysing)
EC 6.3.4.3 formate—tetrahydrofolate ligase
EC 6.3.4.4 adenylosuccinate synthase
EC 6.3.4.5 argininosuccinate synthase
EC 6.3.4.6 urea carboxylase
EC 6.3.4.7 ribose-5-phosphate—ammonia ligase
EC 6.3.4.8 imidazoleacetate—phosphoribosyldiphosphate ligase
EC 6.3.4.9 biotin—[methylmalonyl-CoA-carboxytransferase] ligase
EC 6.3.4.10 biotin—[propionyl-CoA-carboxylase (ATP-hydrolysing)] ligase
EC 6.3.4.11 biotin—[methylcrotonoyl-CoA-carboxylase] ligase
EC 6.3.4.12 glutamate—methylamine ligase
EC 6.3.4.13 phosphoribosylamine—glycine ligase
EC 6.3.4.14 biotin carboxylase
EC 6.3.4.15 biotin—[acetyl-CoA-carboxylase] ligase
EC 6.3.4.16 carbamoyl-phosphate synthase (ammonia)
EC 6.3.4.17 formate—dihydrofolate ligase
EC 6.3.4.18 5-(carboxyamino)imidazole ribonucleotide synthase
EC 6.3.4.19 tRNAIle-lysidine synthetase
EC 6.3.4.20 7-cyano-7-deazaguanine synthase
EC 6.3.4.21 nicotinate phosphoribosyltransferase
EC 6.3.4.22 tRNAIle2-agmatinylcytidine synthase
EC 6.3.4.23 formate—phosphoribosylaminoimidazolecarboxamide ligase
EC 6.3.4.24 tyramine—L-glutamate ligase

EC 6.3.5 Carbon-Nitrogen Ligases with Glutamine as Amido-N-Donor

EC 6.3.5.1 NAD+ synthase (glutamine-hydrolysing)
EC 6.3.5.2 GMP synthase (glutamine-hydrolysing)
EC 6.3.5.3 phosphoribosylformylglycinamidine synthase
EC 6.3.5.4 asparagine synthase (glutamine-hydrolysing)
EC 6.3.5.5 carbamoyl-phosphate synthase (glutamine-hydrolysing)
EC 6.3.5.6 asparaginyl-tRNA synthase (glutamine-hydrolysing)
EC 6.3.5.7 glutaminyl-tRNA synthase (glutamine-hydrolysing)
EC 6.3.5.8 now EC 2.6.1.85
EC 6.3.5.9 hydrogenobyrinic acid a,c-diamide synthase (glutamine-hydrolysing)
EC 6.3.5.10 adenosylcobyric acid synthase (glutamine-hydrolysing) EC 6.3.5.11 cobyrinate a,c-diamide synthase
EC 6.3.5.12 Ni-sirohydrochlorin a,c-diamide synthase

EC 6.4 Forming Carbon-Carbon Bonds

EC 6.4.1.1 pyruvate carboxylase
EC 6.4.1.2 acetyl-CoA carboxylase
EC 6.4.1.3 propionyl-CoA carboxylase
EC 6.4.1.4 methylcrotonoyl-CoA carboxylase
EC 6.4.1.5 geranoyl-CoA carboxylase
EC 6.4.1.6 acetone carboxylase
EC 6.4.1.7 2-oxoglutarate carboxylase
EC 6.4.1.8 acetophenone carboxylase
EC 6.4.1.9 coenzyme F430 synthetase

EC 6.5 Forming Phosphoric Ester Bonds

EC 6.5.1.1 DNA ligase (ATP)
EC 6.5.1.2 DNA ligase (NAD+)
EC 6.5.1.3 RNA ligase (ATP)
EC 6.5.1.4 RNA 3'-terminal-phosphate cyclase (ATP)
EC 6.5.1.5 RNA 3'-terminal-phosphate cyclase (GTP)
EC 6.5.1.6 DNA ligase (ATP or NAD+)
EC 6.5.1.7 DNA ligase (ATP, ADP or GTP)
EC 6.5.1.8 3'-phosphate/5'-hydroxy nucleic acid ligase

EC 6.6 Forming Nitrogen—Metal Bonds

EC 6.6.1 Forming Coordination Complexes

EC 6.6.1.1 magnesium chelatase
EC 6.6.1.2 cobaltochelatase


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