This list contains a list of EC numbers for the fifth group, EC 5, isomerases, 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 5.1: Epimerases and racemases
EC 5.1.1: Acting on Amino acids and Derivatives EC 5.1.1.1: alanine racemase EC 5.1.1.2: methionine racemase EC 5.1.1.3: glutamate racemase EC 5.1.1.4: proline racemase EC 5.1.1.5: lysine racemase EC 5.1.1.6: threonine racemase EC 5.1.1.7: diaminopimelate epimerase EC 5.1.1.8: 4-hydroxyproline epimerase EC 5.1.1.9: arginine racemase EC 5.1.1.10: amino-acid racemase EC 5.1.1.11: phenylalanine racemase (ATP-hydrolysing) EC 5.1.1.12: ornithine racemase EC 5.1.1.13: aspartate racemase EC 5.1.1.14: nocardicin-A epimerase EC 5.1.1.15: 2-aminohexano-6-lactam racemase EC 5.1.1.16: protein-serine epimerase EC 5.1.1.17: isopenicillin-N epimerase EC 5.1.1.18: serine racemase EC 5.1.1.20: L-Ala-D/L-Glu epimerase EC 5.1.1.21: isoleucine 2-epimerase EC 5.1.1.22: 4-hydroxyproline betaine 2-epimerase EC 5.1.1.23: UDP-N-acetyl-α-D-muramoyl-L-alanyl-L-glutamate epimerase EC 5.1.1.24: histidine racemase
EC 5.1.2: Acting on Hydroxy acids and Derivatives EC 5.1.2.1: lactate racemase EC 5.1.2.2: mandelate racemase EC 5.1.2.3: 3-hydroxybutyryl-CoA epimerase EC 5.1.2.4: acetoin racemase EC 5.1.2.5: tartrate epimerase EC 5.1.2.6: isocitrate epimerase EC 5.1.2.7: tagaturonate epimerase
EC 5.1.3: Acting on Carbohydrates and Derivatives EC 5.1.3.1: ribulose-phosphate 3-epimerase EC 5.1.3.2: UDP-glucose 4-epimerase EC 5.1.3.3: aldose 1-epimerase EC 5.1.3.4: L-ribulose-5-phosphate 4-epimerase EC 5.1.3.5: UDP-arabinose 4-epimerase EC 5.1.3.6: UDP-glucuronate 4-epimerase EC 5.1.3.7: UDP-N-acetylglucosamine 4-epimerase EC 5.1.3.8: N-acylglucosamine 2-epimerase EC 5.1.3.9: N-acylglucosamine-6-phosphate 2-epimerase EC 5.1.3.10: CDP-paratose 2-epimerase EC 5.1.3.11: cellobiose epimerase EC 5.1.3.12: The enzyme has never been purified and the activity was later shown not to exist EC 5.1.3.13: dTDP-4-dehydrorhamnose 3,5-epimerase EC 5.1.3.14: UDP-N-acetylglucosamine 2-epimerase (non-hydrolysing) EC 5.1.3.15: glucose-6-phosphate 1-epimerase EC 5.1.3.16: UDP-glucosamine 4-epimerase EC 5.1.3.17: heparosan-N-sulfate-glucuronate 5-epimerase EC 5.1.3.18: GDP-mannose 3,5-epimerase EC 5.1.3.19: chondroitin-glucuronate 5-epimerase EC 5.1.3.20: ADP-glyceromanno-heptose 6-epimeras EC 5.1.3.21: maltose epimerase EC 5.1.3.22: L-ribulose-5-phosphate 3-epimerase EC 5.1.3.23: UDP-2,3-diacetamido-2,3-dideoxyglucuronic acid 2-epimerase EC 5.1.3.24: N-acetylneuraminate epimerase EC 5.1.3.25: dTDP-L-rhamnose 4-epimerase EC 5.1.3.26: N-acetyl-α-D-glucosaminyl-diphospho-ditrans,octacis-undecaprenol 4-epimerase EC 5.1.3.27: dTDP-4-dehydro-6-deoxy-D-glucose 3-epimerase EC 5.1.3.28: UDP-N-acetyl-L-fucosamine synthase EC 5.1.3.29: L-fucose mutarotase EC 5.1.3.30: D-psicose 3-epimerase EC 5.1.3.31: D-tagatose 3-epimerase EC 5.1.3.32: L-rhamnose mutarotase EC 5.1.3.33: 2-epi-5-epi-valiolone epimerase EC 5.1.3.34: monoglucosyldiacylglycerol epimerase EC 5.1.3.35: 2-epi-5-epi-valiolone 7-phosphate 2-epimerase EC 5.1.3.36: heparosan-glucuronate 5-epimerase EC 5.1.3.37: mannuronan 5-epimerase EC 5.1.3.38: D-erythrulose 1-phosphate 3-epimerase EC 5.1.3.39: L-erythrulose 4-phosphate epimerase. The activity has been shown not to take place. EC 5.1.3.40: D-tagatose 6-phosphate 4-epimerase EC 5.1.3.41: fructoselysine 3-epimerase EC 5.1.3.42: D-glucosamine-6-phosphate 4-epimerase EC 5.1.3.43: sulfoquinovose mutarotase EC 5.1.3.44: mannose 2-epimerase
EC 5.1.99: Acting on Other Compounds EC 5.1.99.1: methylmalonyl-CoA epimerase EC 5.1.99.2: 16-hydroxysteroid epimerase EC 5.1.99.3: allantoin racemase EC 5.1.99.4: α-methylacyl-CoA racemase EC 5.1.99.5: hydantoin racemase EC 5.1.99.6: NAD(P)H-hydrate epimerase EC 5.1.99.7: dihydroneopterin triphosphate 2′-epimerase EC 5.1.99.8: 7,8-dihydroneopterin epimerase
EC 5.2: cis-trans-Isomerases
EC 5.2.1: cis-trans Isomerases (only sub-subclass identified to date) EC 5.2.1.1: maleate isomerase EC 5.2.1.2: maleylacetoacetate isomerase EC 5.2.1.3: Now known to be catalysed by a pathway involving EC 1.1.1.300, NADP-retinol dehydrogenase; EC 2.3.1.135, phosphatidylcholine—retinol O-acyltransferase; EC 3.1.1.64, retinoid isomerohydrolase; and EC 1.1.1.315, 11-cis-retinol dehydrogenase. EC 5.2.1.4: maleylpyruvate isomerase EC 5.2.1.5: linoleate isomerase EC 5.2.1.6: furylfuramide isomerase EC 5.2.1.7: transferred to EC 3.1.1.64, retinoid isomerohydrolase EC 5.2.1.8: peptidylprolyl isomerase EC 5.2.1.9: farnesol 2-isomerase EC 5.2.1.10: 2-chloro-4-carboxymethylenebut-2-en-1,4-olide isomerase EC 5.2.1.11: DELETED "4-hydroxyphenylacetaldehyde-oxime isomerase" – The existence of this enzyme has been called into question by one of the authors of the reference cited EC 5.2.1.12: ζ-carotene isomerase EC 5.2.1.13: prolycopene isomerase EC 5.2.1.14: β-carotene isomerase
EC 5.3: Intramolecular Oxidoreductases
EC 5.3.1: Interconverting Aldoses and Ketoses EC 5.3.1.1: triose-phosphate isomerase EC 5.3.1.2: deleted EC 5.3.1.3: D-arabinose isomerase EC 5.3.1.4: L-arabinose isomerase EC 5.3.1.5: xylose isomerase EC 5.3.1.6: ribose-5-phosphate isomerase EC 5.3.1.7: mannose isomerase EC 5.3.1.8: mannose-6-phosphate isomerase EC 5.3.1.9: glucose-6-phosphate isomerase EC 5.3.1.10: Now EC 3.5.99.6, glucosamine-6-phosphate deaminase EC 5.3.1.11: deleted EC 5.3.1.12: glucuronate isomerase EC 5.3.1.13: arabinose-5-phosphate isomerase EC 5.3.1.14: L-rhamnose isomerase EC 5.3.1.15: D-lyxose ketol-isomerase EC 5.3.1.16: 1-(5-phosphoribosyl)-5-[(5-phosphoribosylamino)methylideneamino]imidazole-4-carboxamide isomerase EC 5.3.1.17: 5-dehydro-4-deoxy-D-glucuronate isomerase EC 5.3.1.18: deleted: reaction is due to EC 5.3.1.9 glucose-6-phosphate isomerase, in the presence of arsenate, or EC 5.3.1.5 xylose isomerase EC 5.3.1.19: Now EC 2.6.1.16, glutamine—fructose-6-phosphate transaminase (isomerizing) EC 5.3.1.20: ribose isomerase EC 5.3.1.21: corticosteroid side-chain-isomerase EC 5.3.1.22: hydroxypyruvate isomerase EC 5.3.1.23: S-methyl-5-thioribose-1-phosphate isomerase EC 5.3.1.24: phosphoribosylanthranilate isomerase EC 5.3.1.25: L-fucose isomerase EC 5.3.1.26: galactose-6-phosphate isomerase EC 5.3.1.27: 6-phospho-3-hexuloisomerase EC 5.3.1.28: D-sedoheptulose 7-phosphate isomerase EC 5.3.1.29: ribose 1,5-bisphosphate isomerase EC 5.3.1.30: 5-deoxy-glucuronate isomerase EC 5.3.1.31: sulfoquinovose isomerase EC 5.3.1.32: (4S)-4-hydroxy-5-phosphooxypentane-2,3-dione isomerase EC 5.3.1.33: L-erythrulose 1-phosphate isomerase EC 5.3.1.34: D-erythrulose 4-phosphate isomerase EC 5.3.1.35: 2-dehydrotetronate isomerase EC 5.3.1.36: D-apiose isomerase
EC 5.3.2: Interconverting Keto- and Enol-Groups EC 5.3.2.1: phenylpyruvate tautomerase EC 5.3.2.2: oxaloacetate tautomerase EC 5.3.2.3: TDP-4-oxo-6-deoxy-α-glucose-3,4-oxoisomerase (dTDP-3-dehydro-6-deoxy-α-D-galactopyranose-forming) EC 5.3.2.4: TDP-4-oxo-6-deoxy-α-D-glucose-3,4-oxoisomerase (dTDP-3-dehydro-6-deoxy-α-D-glucopyranose-forming) EC 5.3.2.5: 2,3-diketo-5-methylthiopentyl-1-phosphate enolase EC 5.3.2.6: 2-hydroxymuconate tautomerase EC 5.3.2.7: ascopyrone tautomerase EC 5.3.2.8: 4-oxalomesaconate tautomerase
EC 5.3.3: Transposing C=C Bonds EC 5.3.3.1: steroid Δ-isomerase EC 5.3.3.2: isopentenyl-diphosphate Δ-isomerase EC 5.3.3.3: vinylacetyl-CoA Δ-isomerase EC 5.3.3.4: muconolactone Δ-isomerase EC 5.3.3.5: cholestenol Δ-isomerase EC 5.3.3.6: methylitaconate Δ-isomerase EC 5.3.3.7: aconitate Δ-isomerase EC 5.3.3.8: Δ3-Δ2-enoyl-CoA isomerase EC 5.3.3.9: prostaglandin-A1 Δ-isomerase EC 5.3.3.10: 5-carboxymethyl-2-hydroxymuconate Δ-isomerase EC 5.3.3.11: isopiperitenone Δ-isomerase EC 5.3.3.12: L-dopachrome isomerase EC 5.3.3.13: polyenoic fatty acid isomerase EC 5.3.3.14: trans-2-decenoyl-[acyl-carrier protein] isomerase EC 5.3.3.15: Now EC 5.3.2.7, ascopyrone tautomerase EC 5.3.3.16: Now EC 5.3.2.8, 4-oxalomesaconate tautomerase EC 5.3.3.17: trans-2,3-dihydro-3-hydroxyanthranilate isomerase EC 5.3.3.18: 2-(1,2-epoxy-1,2-dihydrophenyl)acetyl-CoA isomerase EC 5.3.3.19: 3-[(4R)-4-hydroxycyclohexa-1,5-dien-1-yl]-2-oxopropanoate isomerase EC 5.3.3.20: Now EC 5.4.99.64, 2-hydroxyisobutanoyl-CoA mutase EC 5.3.3.21: Δ3,5-Δ2,4-dienoyl-CoA isomerase EC 5.3.3.22: lutein isomerase EC 5.3.3.23: S-methyl-5-thioribulose 1-phosphate isomerase
EC 5.3.4: Transposing S-S Bonds EC 5.3.4.1: protein disulfide-isomerase
EC 5.3.99: Other Intramolecular Oxidoreductases EC 5.3.99.1: deleted, reaction due to combined action of EC 4.2.1.92 (hydroperoxide dehydratase) and EC 5.3.99.6 (allene-oxide cyclase) EC 5.3.99.2: prostaglandin-D synthase EC 5.3.99.3: prostaglandin-E synthase EC 5.3.99.4: prostaglandin-I synthase EC 5.3.99.5: thromboxane-A synthase EC 5.3.99.6: allene-oxide cyclase EC 5.3.99.7: styrene-oxide isomerase EC 5.3.99.8: capsanthin/capsorubin synthase EC 5.3.99.9: neoxanthin synthase EC 5.3.99.10: thiazole tautomerase EC 5.3.99.11: 2-keto-myo-inositol isomerase EC 5.3.99.12: lachrymatory factor synthase
EC 5.4: Intramolecular Transferases
EC 5.4.1: Transferring Acyl Groups EC 5.4.1.1: lysolecithin acylmutase EC 5.4.1.2: Now EC 5.4.99.61, precorrin-8X methylmutase EC 5.4.1.3: 2-methylfumaryl-CoA isomerase EC 5.4.1.4: D-galactarolactone isomerase
EC 5.4.2: Phosphotransferases (Phosphomutases) EC 5.4.2.1: Now recognized as two separate enzymes EC 5.4.2.11, phosphoglycerate mutase (2,3-diphosphoglycerate-dependent) and EC 5.4.2.12, phosphoglycerate mutase (2,3-diphosphoglycerate-independent) EC 5.4.2.2: phosphoglucomutase (α-D-glucose-1,6-bisphosphate-dependent) EC 5.4.2.3: phosphoacetylglucosamine mutase EC 5.4.2.4: bisphosphoglycerate mutase EC 5.4.2.5: phosphoglucomutase (glucose-cofactor) EC 5.4.2.6: β-phosphoglucomutase EC 5.4.2.7: phosphopentomutase EC 5.4.2.8: phosphomannomutase EC 5.4.2.9: phosphoenolpyruvate mutase EC 5.4.2.10: phosphoglucosamine mutase EC 5.4.2.11: phosphoglycerate mutase (2,3-diphosphoglycerate-dependent) EC 5.4.2.12: phosphoglycerate mutase (2,3-diphosphoglycerate-independent) EC 5.4.2.13: phosphogalactosamine mutase
EC 5.4.3: Transferring Amino Groups EC 5.4.3.1: deleted; this reaction was due to a mixture of EC 5.1.1.12 (ornithine racemase) and EC 5.4.3.5 (D-ornithine 4,5-aminomutase) EC 5.4.3.2: lysine 2,3-aminomutase EC 5.4.3.3: lysine 5,6-aminomutase EC 5.4.3.4: Now included in EC 5.4.3.3, lysine 5,6-aminomutase EC 5.4.3.5: D-ornithine 4,5-aminomutase EC 5.4.3.6: tyrosine 2,3-aminomutase EC 5.4.3.7: leucine 2,3-aminomutase EC 5.4.3.8: glutamate-1-semialdehyde 2,1-aminomutase EC 5.4.3.9: glutamate 2,3-aminomutase EC 5.4.3.10: phenylalanine aminomutase (L-β-phenylalanine forming) EC 5.4.3.11: phenylalanine aminomutase (D-β-phenylalanine forming)
EC 5.4.4: Transferring hydroxy groups EC 5.4.4.1: (hydroxyamino)benzene mutase EC 5.4.4.2: isochorismate synthase EC 5.4.4.3: 3-(hydroxyamino)phenol mutase EC 5.4.4.4: geraniol isomerase EC 5.4.4.5: 9,12-octadecadienoate 8-hydroperoxide 8R-isomerase EC 5.4.4.6: 9,12-octadecadienoate 8-hydroperoxide 8S-isomerase EC 5.4.4.7: hydroperoxy icosatetraenoate isomerase EC 5.4.4.8: linalool isomerase EC 5.4.4.9: pyrogallol hydroxytransferase
EC 5.4.99: Transferring Other Groups EC 5.4.99.1: methylaspartate mutase EC 5.4.99.2: methylmalonyl-CoA mutase EC 5.4.99.3: 2-acetolactate mutase EC 5.4.99.4: 2-methyleneglutarate mutase EC 5.4.99.5: chorismate mutase EC 5.4.99.6: Now EC 5.4.4.2, isochorismate synthase EC 5.4.99.7: lanosterol synthase EC 5.4.99.8: cycloartenol synthase EC 5.4.99.9: UDP-galactopyranose mutase EC 5.4.99.10: Now included with EC 5.4.99.11, isomaltulose synthase EC 5.4.99.11: isomaltulose synthase EC 5.4.99.12: tRNA pseudouridine38-40 synthase EC 5.4.99.13: isobutyryl-CoA mutase EC 5.4.99.14: 4-carboxymethyl-4-methylbutenolide mutase EC 5.4.99.15: (1→4)-α-D-glucan 1-α-D-glucosylmutase EC 5.4.99.16: maltose α-D-glucosyltransferase EC 5.4.99.17: squalene—hopene cyclase EC 5.4.99.18: 5-(carboxyamino)imidazole ribonucleotide mutase EC 5.4.99.19: 16S rRNA pseudouridine516 synthase EC 5.4.99.20: 23S rRNA pseudouridine2457 synthase EC 5.4.99.21: 23S rRNA pseudouridine2604 synthase EC 5.4.99.22: 23S rRNA pseudouridine2605 synthase EC 5.4.99.23: 23S rRNA pseudouridine1911/1915/1917 synthase EC 5.4.99.24: 23S rRNA pseudouridine955/2504/2580 synthase EC 5.4.99.25: tRNA pseudouridine55 synthase EC 5.4.99.26: tRNA pseudouridine65 synthase EC 5.4.99.27: tRNA pseudouridine13 synthase EC 5.4.99.28: RNA pseudouridine32 synthase EC 5.4.99.29: 23S rRNA pseudouridine746 synthase EC 5.4.99.30: UDP-arabinopyranose mutase EC 5.4.99.31: thalianol synthase EC 5.4.99.32: protostadienol synthase EC 5.4.99.33: cucurbitadienol synthase EC 5.4.99.34: germanicol synthase EC 5.4.99.35: taraxerol synthase EC 5.4.99.36: isomultiflorenol synthase EC 5.4.99.37: dammaradiene synthase EC 5.4.99.38: camelliol C synthase EC 5.4.99.39: β-amyrin synthase EC 5.4.99.40: α-amyrin synthase EC 5.4.99.41: lupeol synthase EC 5.4.99.42: tRNA pseudouridine31 synthase EC 5.4.99.43: 21S rRNA pseudouridine2819 synthase EC 5.4.99.44: mitochondrial tRNA pseudouridine27/28 synthase EC 5.4.99.45: tRNA pseudouridine38/39 synthase EC 5.4.99.46: shionone synthase EC 5.4.99.47: parkeol synthase EC 5.4.99.48: achilleol B synthase EC 5.4.99.49: glutinol synthase EC 5.4.99.50: friedelin synthase EC 5.4.99.51: baccharis oxide synthase EC 5.4.99.52: α-seco-amyrin synthase EC 5.4.99.53: marneral synthase EC 5.4.99.54: β-seco-amyrin synthase EC 5.4.99.55: δ-amyrin synthase EC 5.4.99.56: tirucalladienol synthase EC 5.4.99.57: baruol synthase EC 5.4.99.58: methylornithine synthase EC 5.4.99.59: dTDP-fucopyranose mutase EC 5.4.99.60: cobalt-precorrin-8 methylmutase EC 5.4.99.61: precorrin-8X methylmutase EC 5.4.99.62: D-ribose pyranase EC 5.4.99.63: ethylmalonyl-CoA mutase EC 5.4.99.64: 2-hydroxyisobutanoyl-CoA mutase EC 5.4.99.65: pre-α-onocerin synthase EC 5.4.99.66: α-onocerin synthase EC 5.4.99.67: 4-amino-4-deoxychorismate mutase
EC 5.5: Intramolecular Lyases
EC 5.5.1: Intramolecular lyases (only sub-subclass identified to date) EC 5.5.1.1: muconate cycloisomerase EC 5.5.1.2: 3-carboxy-cis,cis-muconate cycloisomerase EC 5.5.1.3: tetrahydroxypteridine cycloisomerase EC 5.5.1.4: inositol-3-phosphate synthase EC 5.5.1.5: carboxy-cis,cis-muconate cyclase EC 5.5.1.6: chalcone isomerase EC 5.5.1.7: chloromuconate cycloisomerase EC 5.5.1.8: (+)-bornyl diphosphate synthase EC 5.5.1.9: cycloeucalenol cycloisomerase EC 5.5.1.10: α-pinene-oxide decyclase EC 5.5.1.11: dichloromuconate cycloisomerase EC 5.5.1.12: copalyl diphosphate synthase EC 5.5.1.13: ent-copalyl diphosphate synthase EC 5.5.1.14: syn-copalyl-diphosphate synthase EC 5.5.1.15: terpentedienyl-diphosphate synthase EC 5.5.1.16: halimadienyl-diphosphate synthase EC 5.5.1.17: (S)-β-macrocarpene synthase EC 5.5.1.18: lycopene ε-cyclase EC 5.5.1.19: lycopene β-cyclase EC 5.5.1.20: prosolanapyrone-III cycloisomerase EC 5.5.1.21: [[copal-8-ol diphosphate synthase. The enzyme was discovered at the public-review stage to have been misclassified and so was withdrawn. See EC 4.2.1.133, copal-8-ol diphosphate hydratase]] EC 5.5.1.22: (–)-bornyl diphosphate synthase EC 5.5.1.23: aklanonic acid methyl ester cyclase EC 5.5.1.24: tocopherol cyclase EC 5.5.1.25: 3,6-anhydro-L-galactonate cycloisomerase EC 5.5.1.26: nogalonic acid methyl ester cyclase EC 5.5.1.27: D-galactarolactone cycloisomerase EC 5.5.1.28: (–)-kolavenyl diphosphate synthase EC 5.5.1.29: (+)-kolavenyl diphosphate synthase EC 5.5.1.30: labda-7,13-dienyl diphosphate synthase EC 5.5.1.31: hapalindole H synthase EC 5.5.1.32: 12-epi-hapalindole U synthase EC 5.5.1.33: 12-epi-fischerindole U synthase EC 5.5.1.34: (+)-cis,trans-nepetalactol synthase EC 5.5.1.35: (+)-cis,cis-nepetalactol synthase EC 5.5.1.36: hapalindole U synthase EC 5.5.1.37: catharanthine synthase EC 5.5.1.38: tabersonine synthase
EC 5.6: Isomerases altering macromolecular conformation
EC 5.6.1: Enzymes altering polypeptide conformation or assembly EC 5.6.1.1: microtubule-severing ATPase EC 5.6.1.2: dynein ATPase EC 5.6.1.3: plus-end-directed kinesin ATPase EC 5.6.1.4: minus-end-directed kinesin ATPase EC 5.6.1.5: proteasome ATPase EC 5.6.1.6: channel-conductance-controlling ATPase EC 5.6.1.7: chaperonin ATPase EC 5.6.1.8: myosin ATPase EC 5.6.1.9: (R)-2-hydroxyacyl-CoA dehydratase activating ATPase
EC 5.6.2: Enzymes altering nucleic acid conformation EC 5.6.2.1: DNA topoisomerase EC 5.6.2.2: DNA topoisomerase (ATP-hydrolyzing) EC 5.6.2.3: DNA 5'-3' helicase EC 5.6.2.4: DNA 3'-5' helicase
EC 5.99: Other Isomerases
EC 5.99.1: Sole sub-subclass for isomerases that do not belong in the other subclasses EC 5.99.1.1: thiocyanate isomerase EC 5.99.1.2: Now EC 5.6.2.1, DNA topoisomerase EC 5.99.1.3: Now EC 5.6.2.2, DNA topoisomerase (ATP-hydrolysing) EC 5.99.1.4: 2-hydroxychromene-2-carboxylate isomerase
References