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.

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 5.1.2: 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 5.1.3: 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: UDP-glucuronate 5'-epimerase
• EC 5.1.3.13: dTDP-4-dehydrorhamnose 3,5-epimerase
• EC 5.1.3.14: UDP-N-acetylglucosamine 2-epimerase
• 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-epimerase
• EC 5.1.3.21: maltose epimerase
• EC 5.1.3.22: L-ribulose-5-phosphate 3-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: a-methylacyl-CoA racemase

EC 5.2: cis-trans-Isomerases

• EC 5.2.1.1: maleate isomerase
• EC 5.2.1.2: maleylacetoacetate isomerase
• EC 5.2.1.3: retinal isomerase
• 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: retinol isomerase
• 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 entry

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: 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
• 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: 4-deoxy-L-threo-5-hexosulose-uronate ketol-isomerase
• EC 5.3.1.18: deleted
• EC 5.3.1.19: now EC 2.6.1.16
• 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: 5-methylthioribose-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 5.3.2: Interconverting Keto- and Enol-Groups

• EC 5.3.2.1: phenylpyruvate tautomerase
• EC 5.3.2.2: oxaloacetate tautomerase

EC 5.3.3: Transposing C=C Bonds

• EC 5.3.3.1: steroid D-isomerase
• EC 5.3.3.2: isopentenyl-diphosphate D-isomerase
• EC 5.3.3.3: vinylacetyl-CoA D-isomerase
• EC 5.3.3.4: muconolactone D-isomerase
• EC 5.3.3.5: cholestenol D-isomerase
• EC 5.3.3.6: methylitaconate D-isomerase
• EC 5.3.3.7: aconitate D-isomerase
• EC 5.3.3.8: dodecenoyl-CoA D-isomerase
• EC 5.3.3.9: prostaglandin-A1 D-isomerase
• EC 5.3.3.10: 5-carboxymethyl-2-hydroxymuconate D-isomerase
• EC 5.3.3.11: isopiperitenone D-isomerase
• EC 5.3.3.12: L-dopachrome isomerase
• EC 5.3.3.13: polyenoic fatty acid 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
• 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 5.4: Intramolecular Transferases

EC 5.4.1: Transferring Acyl Groups

• EC 5.4.1.1: lysolecithin acylmutase
• EC 5.4.1.2: precorrin-8X methylmutase

EC 5.4.2: Phosphotransferases (Phosphomutases)

• EC 5.4.2.1: phosphoglycerate mutase
• EC 5.4.2.2: phosphoglucomutase
• 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: b-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 5.4.3: Transferring Amino Groups

• EC 5.4.3.1: deleted
• EC 5.4.3.2: lysine 2,3-aminomutase
• EC 5.4.3.3: b-lysine 5,6-aminomutase
• EC 5.4.3.4: D-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 5.4.4: 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 5.4.99: 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
• 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: deleted, included in EC 5.4.99.11
• EC 5.4.99.11: isomaltulose synthase
• EC 5.4.99.12: tRNA-pseudouridine synthase I
• EC 5.4.99.13: isobutyryl-CoA mutase
• EC 5.4.99.14: 4-carboxymethyl-4-methylbutenolide mutase
• EC 5.4.99.15: (1(arrow to right)4)-a-D-glucan 1-a-D-glucosylmutase
• EC 5.4.99.16: maltose a-D-glucosyltransferase
• EC 5.4.99.17: squalene—hopene cyclase

EC 5.5: Intramolecular Lyases

• 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: a-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 5.99: Other Isomerases

• EC 5.99.1.1: thiocyanate isomerase
• EC 5.99.1.2: DNA topoisomerase
• EC 5.99.1.3: DNA topoisomerase (ATP-hydrolysing)