This list contains a list of EC numbers for the sixth group, EC 6, ligases, placed in numerical order as determined by the Nomenclature Committee of the International Union of Biochemistry and Molecular Biology. All official information is tabulated at the website of the committee. The database is developed and maintained by Andrew McDonald.
EC 6.1: Forming Carbon-Oxygen Bonds
EC 6.1.1: Ligases Forming Aminoacyl-tRNA and Related Compounds (Aminoacyl tRNA synthetase) 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: The tRNAPyl is now known only to be charged with pyrrolysine (cf. EC 6.1.1.26) EC 6.1.1.26: pyrrolysine—tRNAPyl ligase EC 6.1.1.27: O-phospho-L-serine—tRNA ligase EC 6.1.1.28: "proline/cysteine—tRNA ligase". Later published work having demonstrated that this was not a genuine enzyme, EC 6.1.1.28 was withdrawn at the public-review stage before being made official.
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 6.1.3: Cyclo-ligases EC 6.1.3.1: olefin β-lactone synthetase
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: medium-chain acyl-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: carboxylic 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: Activity covered by EC 6.2.1.30, phenylacetate—CoA ligase 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, identical to EC 6.2.1.7, cholate—CoA ligase 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: acetate—[acyl-carrier protein] 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 (AMP-forming) 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 6.2.1.50: 4-hydroxybenzoate adenylyltransferase FadD22 EC 6.2.1.51: 4-hydroxyphenylalkanoate adenylyltransferase FadD29 EC 6.2.1.52: L-firefly luciferin—CoA ligase EC 6.2.1.53: L-proline—[L-prolyl-carrier protein] ligase EC 6.2.1.54: D-alanine—[D-alanyl-carrier protein] ligase EC 6.2.1.55: E1 SAMP-activating enzyme EC 6.2.1.56: 4-hydroxybutyrate—CoA ligase (ADP-forming) EC 6.2.1.57: long-chain fatty acid adenylase/transferase FadD23 EC 6.2.1.58: isophthalate—CoA ligase EC 6.2.1.59: long-chain fatty acid adenylase/transferase FadD26 EC 6.2.1.60: marinolic acid—CoA ligase EC 6.2.1.61: salicylate—[aryl-carrier protein] ligase EC 6.2.1.62: 3,4-dihydroxybenzoate—[aryl-carrier protein] ligase EC 6.2.1.63: L-arginine—[L-arginyl-carrier protein] ligase EC 6.2.1.64: E1 NEDD8-activating enzyme EC 6.2.1.65: salicylate—CoA ligase EC 6.2.1.66: glyine—[glycyl-carrier protein] ligase EC 6.2.1.67: L-alanine—[L-alanyl-carrier protein] ligase EC 6.2.1.68: L-glutamate—[L-glutamyl-carrier protein] ligase EC 6.2.1.69: L-cysteine—[L-cysteinyl-carrier protein] ligase EC 6.2.1.70: L-threonine—[L-threonyl-carrier protein] ligase EC 6.2.1.71: 2,3-dihydroxybenzoate—[aryl-carrier protein] ligase EC 6.2.1.72: L-serine—[L-seryl-carrier protein] ligase EC 6.2.1.73: L-tryptophan—[L-tryptophyl-carrier protein] ligase EC 6.2.1.74: 3-amino-5-hydroxybenzoate—[acyl-carrier protein] ligase EC 6.2.1.75: indoleacetate—CoA ligase EC 6.2.1.76: malonate—CoA ligase *
EC 6.2.2: Amide—thiol ligases EC 6.2.2.1: thioglycine synthase EC 6.2.2.2: oxazoline synthase EC 6.2.2.3: thiazoline synthase
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, phosphoribosylamine—glycine ligase 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: [[The enzyme was discovered at the public-review stage to have been misclassified and so was withdrawn. See EC 6.3.3.6, carbapenam-3-carboxylate synthase]] 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 6.3.1.21: phosphoribosylglycinamide formyltransferase 2
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-acetylmuramoyl-L-alanine—D-glutamate ligase EC 6.3.2.10: UDP-N-acetylmuramoyl-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, The activity observed is due to EC 6.3.2.10, UDP-N-acetylmuramoyl-tripeptideD-alanyl-D-alanine ligase 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: The ubiquitinylation process is now known to be performed by several enzymes in sequence, starting with EC 6.2.1.45 (ubiquitin-activating enzyme E1) and followed by several transfer reactions, including those of EC 2.3.2.23 (E2 ubiquitin-conjugating enzyme) and EC 2.3.2.27 (RING-type E3 ubiquitin transferase) EC 6.3.2.20: indoleacetate—lysine synthetase EC 6.3.2.21: [[The reaction is performed by the sequential action of EC 6.2.1.45 (ubiquitin-activating enzyme E1), several ubiquitin transferases and finally by EC 2.3.2.27 (ubiquitin transferase RING E3 (calmodulin-selective))|The reaction is performed by the sequential action of EC 6.2.1.45 (ubiquitin-activating enzyme E1), several ubiquitin transferases and finally by EC 2.3.2.27 [ubiquitin transferase RING E3 (calmodulin-selective)]]] EC 6.3.2.22: Now EC 6.3.1.14, diphthine—ammonia ligase. 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: [[The activity is covered by two independent enzymes, EC 6.3.2.38 N^2-citryl-N^6-acetyl-N^6-hydroxylysine synthase, and EC 6.3.2.39, aerobactin synthase|The activity is covered by two independent enzymes, EC 6.3.2.38 N2-citryl-N6-acetyl-N6-hydroxylysine synthase, and EC 6.3.2.39, aerobactin synthase]] EC 6.3.2.28: Now EC 6.3.2.49, L-alanine-L-anticapsin 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 F420-0: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: [amino-group carrier protein]—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 6.3.2.52: jasmonoyl—L-amino acid ligase EC 6.3.2.53: UDP-N-acetylmuramoyl-L-alanine—L-glutamate ligase EC 6.3.2.54: L-2,3-diaminopropanoate—citrate ligase EC 6.3.2.55: 2-[(L-alanin-3-ylcarbamoyl)methyl]-3-(2-aminoethylcarbamoyl)-2-hydroxypropanoate synthase EC 6.3.2.56: staphyloferrin B synthase EC 6.3.2.57: staphyloferrin A synthase EC 6.3.2.58: D-ornithine—citrate ligase EC 6.3.2.59: 3-methyl-D-ornithine—L-lysine ligase EC 6.3.2.60: glutamate—[amino group carrier protein] ligase EC 6.3.2.61: tubulin-glutamate ligase EC 6.3.2.62: β-tubulin-glutamate ligase
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: Now included in EC 6.3.5.2, GMP synthase (glutamine-hydrolysing) 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—[methylmalonyl-CoA-carboxytransferase] 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—[biotin carboxyl-carrier protein] 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 synthase 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 6.3.4.25: 2-amino-2′-deoxyadenylo-succinate synthase
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, aminodeoxychorismate synthase. As ATP is not hydrolysed during the reaction, the classification of the enzyme as a ligase was incorrect 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 6.3.5.13: lipid II isoglutaminyl synthase (glutamine-hydrolysing)
EC 6.4: Forming Carbon-Carbon Bonds
EC 6.4.1: Ligases that form carbon-carbon bonds (only sub-subclass identified to date) 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: Ligases that form phosphoric-ester bonds (only sub-subclass identified to date) 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 6.5.1.9: cyclic 2,3-diphosphoglycerate synthase
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
EC 6.7: Forming nitrogen-nitrogen bonds
EC 6.7.1: Forming diazo bonds EC 6.7.1.1: 3-amino-2-hydroxy-4-methoxybenzoate
References