The following list contains the definitions of enzyme classes,
subclasses and sub-subclasses. If you click on one of the
following lines, you will get a list of all enzymes in the
corresponding classes, with the possibility to obtain a list of all corresponding UniProtKB/Swiss-Prot entries.
1. -. -.- Oxidoreductases.
1. 1. -.- Acting on the CH-OH group of donors.
1. 1. 1.- With NAD(+) or NADP(+) as acceptor.
1. 1. 2.- With a cytochrome as acceptor.
1. 1. 3.- With oxygen as acceptor.
1. 1. 4.- With a disulfide as acceptor.
1. 1. 5.- With a quinone or similar compound as acceptor.
1. 1.99.- With other acceptors.
1. 2. -.- Acting on the aldehyde or oxo group of donors.
1. 2. 1.- With NAD(+) or NADP(+) as acceptor.
1. 2. 2.- With a cytochrome as acceptor.
1. 2. 3.- With oxygen as acceptor.
1. 2. 4.- With a disulfide as acceptor.
1. 2. 7.- With an iron-sulfur protein as acceptor.
1. 2.99.- With other acceptors.
1. 3. -.- Acting on the CH-CH group of donors.
1. 3. 1.- With NAD(+) or NADP(+) as acceptor.
1. 3. 2.- With a cytochrome as acceptor.
1. 3. 3.- With oxygen as acceptor.
1. 3. 5.- With a quinone or related compound as acceptor.
1. 3. 7.- With an iron-sulfur protein as acceptor.
1. 3.99.- With other acceptors.
1. 4. -.- Acting on the CH-NH(2) group of donors.
1. 4. 1.- With NAD(+) or NADP(+) as acceptor.
1. 4. 2.- With a cytochrome as acceptor.
1. 4. 3.- With oxygen as acceptor.
1. 4. 4.- With a disulfide as acceptor.
1. 4. 7.- With an iron-sulfur protein as acceptor.
1. 4.99.- With other acceptors.
1. 5. -.- Acting on the CH-NH group of donors.
1. 5. 1.- With NAD(+) or NADP(+) as acceptor.
1. 5. 3.- With oxygen as acceptor.
1. 5. 4.- With a disulfide as acceptor.
1. 5. 5.- With a quinone or similar compound as acceptor.
1. 5. 7.- With an iron-sulfur protein as acceptor.
1. 5. 8.- With a flavin as acceptor.
1. 5.99.- With other acceptors.
1. 6. -.- Acting on NADH or NADPH.
1. 6. 1.- With NAD(+) or NADP(+) as acceptor.
1. 6. 2.- With a heme protein as acceptor.
1. 6. 3.- With a oxygen as acceptor.
1. 6. 5.- With a quinone or similar compound as acceptor.
1. 6. 6.- With a nitrogenous group as acceptor.
1. 6.99.- With other acceptors.
1. 7. -.- Acting on other nitrogenous compounds as donors.
1. 7. 1.- With NAD(+) or NADP(+) as acceptor.
1. 7. 2.- With a cytochrome as acceptor.
1. 7. 3.- With oxygen as acceptor.
1. 7. 7.- With an iron-sulfur protein as acceptor.
1. 7.99.- With other acceptors.
1. 8. -.- Acting on a sulfur group of donors.
1. 8. 1.- With NAD(+) or NADP(+) as acceptor.
1. 8. 2.- With a cytochrome as acceptor.
1. 8. 3.- With oxygen as acceptor.
1. 8. 4.- With a disulfide as acceptor.
1. 8. 5.- With a quinone or similar compound as acceptor.
1. 8. 7.- With an iron-sulfur protein as acceptor.
1. 8.98.- With other, known, acceptors.
1. 8.99.- With other acceptors.
1. 9. -.- Acting on a heme group of donors.
1. 9. 3.- With oxygen as acceptor.
1. 9. 6.- With a nitrogenous group as acceptor.
1. 9.99.- With other acceptors.
1.10. -.- Acting on diphenols and related substances as donors.
1.10. 1.- With NAD(+) or NADP(+) as acceptor.
1.10. 2.- With a cytochrome as acceptor.
1.10. 3.- With oxygen as acceptor.
1.10.99.- With other acceptors.
1.11. -.- Acting on a peroxide as acceptor.
1.11. 1.- Peroxidases.
1.12. -.- Acting on hydrogen as donor.
1.12. 1.- With NAD(+) or NADP(+) as acceptor.
1.12. 2.- With a cytochrome as acceptor.
1.12. 5.- With a quinone or similar compound as acceptor.
1.12. 7.- With an iron-sulfur protein as acceptor.
1.12.98.- With other known acceptors.
1.12.99.- With other acceptors.
1.13. -.- Acting on single donors with incorporation of molecular oxygen.
1.13.11.- With incorporation of two atoms of oxygen.
1.13.12.- With incorporation of one atom of oxygen.
1.13.99.- Miscellaneous (requires further characterization).
1.14. -.- Acting on paired donors, with incorporation or reduction of
1.14.11.- With 2-oxoglutarate as one donor, and incorporation of one
1.14.12.- With NADH or NADPH as one donor, and incorporation of two
1.14.13.- With NADH or NADPH as one donor, and incorporation of one atom
1.14.14.- With reduced flavin or flavoprotein as one donor, and
1.14.15.- With a reduced iron-sulfur protein as one donor, and
1.14.16.- With reduced pteridine as one donor, and incorporation of one
1.14.17.- With reduced ascorbate as one donor, and incorporation of one
1.14.18.- With another compound as one donor, and incorporation of one
1.14.19.- With oxidation of a pair of donors resulting in the reduction
1.14.20.- With 2-oxoglutarate as one donor, and the other dehydrogenated.
1.14.21.- With NADH or NADPH as one donor, and the other dehydrogenated.
1.14.99.- Miscellaneous (requires further characterization).
1.15. -.- Acting on superoxide as acceptor.
1.15. 1.- Acting on superoxide as acceptor.
1.16. -.- Oxidizing metal ions.
1.16. 1.- With NAD(+) or NADP(+) as acceptor.
1.16. 3.- With oxygen as acceptor.
1.16. 8.- With flavin as acceptor.
1.17. -.- Acting on CH or CH(2) groups.
1.17. 1.- With NAD(+) or NADP(+) as acceptor.
1.17. 3.- With oxygen as acceptor.
1.17. 4.- With a disulfide as acceptor.
1.17. 5.- With a quinone or similar compound as acceptor.
1.17. 7.- With an iron-sulfur protein as acceptor.
1.17.99.- With other acceptors.
1.18. -.- Acting on iron-sulfur proteins as donors.
1.18. 1.- With NAD(+) or NADP(+) as acceptor.
1.18. 6.- With dinitrogen as acceptor.
1.19. -.- Acting on reduced flavodoxin as donor.
1.19. 6.- With dinitrogen as acceptor.
1.20. -.- Acting on phosphorus or arsenic in donors.
1.20. 1.- Acting on phosphorus or arsenic in donors, with NAD(P)(+) as
1.20. 4.- Acting on phosphorus or arsenic in donors, with disulfide as
1.20.98.- Acting on phosphorus or arsenic in donors, with other, known
1.20.99.- Acting on phosphorus or arsenic in donors, with other
1.21. -.- Acting on x-H and y-H to form an x-y bond.
1.21. 3.- With oxygen as acceptor.
1.21. 4.- With a disulfide as acceptor.
1.21.99.- With other acceptors.
1.97. -.- Other oxidoreductases.
1.97. 1.- Sole sub-subclass for oxidoreductases that do not belong in the
2. -. -.- Transferases.
2. 1. -.- Transferring one-carbon groups.
2. 1. 1.- Methyltransferases.
2. 1. 2.- Hydroxymethyl-, formyl- and related transferases.
2. 1. 3.- Carboxyl- and carbamoyltransferases.
2. 1. 4.- Amidinotransferases.
2. 2. -.- Transferring aldehyde or ketone residues.
2. 2. 1.- Transketolases and transaldolases.
2. 3. -.- Acyltransferases.
2. 3. 1.- Transferring groups other than amino-acyl groups.
2. 3. 2.- Aminoacyltransferases.
2. 3. 3.- Acyl groups converted into alkyl on transfer.
2. 4. -.- Glycosyltransferases.
2. 4. 1.- Hexosyltransferases.
2. 4. 2.- Pentosyltransferases.
2. 4.99.- Transferring other glycosyl groups.
2. 5. -.- Transferring alkyl or aryl groups, other than methyl groups.
2. 5. 1.- Transferring alkyl or aryl groups, other than methyl groups.
2. 6. -.- Transferring nitrogenous groups.
2. 6. 1.- Transaminases (aminotransferases).
2. 6. 3.- Oximinotransferases.
2. 6.99.- Transferring other nitrogenous groups.
2. 7. -.- Transferring phosphorous-containing groups.
2. 7. 1.- Phosphotransferases with an alcohol group as acceptor.
2. 7. 2.- Phosphotransferases with a carboxyl group as acceptor.
2. 7. 3.- Phosphotransferases with a nitrogenous group as acceptor.
2. 7. 4.- Phosphotransferases with a phosphate group as acceptor.
2. 7. 6.- Diphosphotransferases.
2. 7. 7.- Nucleotidyltransferases.
2. 7. 8.- Transferases for other substituted phosphate groups.
2. 7. 9.- Phosphotransferases with paired acceptors.
2. 7.10.- Protein-tyrosine kinases.
2. 7.11.- Protein-serine/threonine kinases.
2. 7.12.- Dual-specificity kinases (those acting on Ser/Thr and Tyr
2. 7.13.- Protein-histidine kinases.
2. 7.99.- Other protein kinases.
2. 8. -.- Transferring sulfur-containing groups.
2. 8. 1.- Sulfurtransferases.
2. 8. 2.- Sulfotransferases.
2. 8. 3.- CoA-transferases.
2. 8. 4.- Transferring alkylthio groups.
2. 9. -.- Transferring selenium-containing groups.
2. 9. 1.- Selenotransferases.
3. -. -.- Hydrolases.
3. 1. -.- Acting on ester bonds.
3. 1. 1.- Carboxylic ester hydrolases.
3. 1. 2.- Thiolester hydrolases.
3. 1. 3.- Phosphoric monoester hydrolases.
3. 1. 4.- Phosphoric diester hydrolases.
3. 1. 5.- Triphosphoric monoester hydrolases.
3. 1. 6.- Sulfuric ester hydrolases.
3. 1. 7.- Diphosphoric monoester hydrolases.
3. 1. 8.- Phosphoric triester hydrolases.
3. 1.11.- Exodeoxyribonucleases producing 5'-phosphomonoesters.
3. 1.13.- Exoribonucleases producing 5'-phosphomonoesters.
3. 1.14.- Exoribonucleases producing 3'-phosphomonoesters.
3. 1.15.- Exonucleases active with either ribo- or deoxyribonucleic acid
3. 1.16.- Exonucleases active with either ribo- or deoxyribonucleic acid
3. 1.21.- Endodeoxyribonucleases producing 5'-phosphomonoesters.
3. 1.22.- Endodeoxyribonucleases producing other than 5'-phosphomonoesters.
3. 1.25.- Site-specific endodeoxyribonucleases specific for altered bases.
3. 1.26.- Endoribonucleases producing 5'-phosphomonoesters.
3. 1.27.- Endoribonucleases producing other than 5'-phosphomonoesters.
3. 1.30.- Endoribonucleases active with either ribo- or deoxyribonucleic
3. 1.31.- Endoribonucleases active with either ribo- or deoxyribonucleic
3. 2. -.- Glycosylases.
3. 2. 1.- Glycosidases, i.e. enzymes hydrolyzing O- and S-glycosyl
3. 2. 2.- Hydrolyzing N-glycosyl compounds.
3. 3. -.- Acting on ether bonds.
3. 3. 1.- Thioether and trialkylsulfonium hydrolases.
3. 3. 2.- Ether hydrolases.
3. 4. -.- Acting on peptide bonds (peptide hydrolases).
3. 4.11.- Aminopeptidases.
3. 4.13.- Dipeptidases.
3. 4.14.- Dipeptidyl-peptidases and tripeptidyl-peptidases.
3. 4.15.- Peptidyl-dipeptidases.
3. 4.16.- Serine-type carboxypeptidases.
3. 4.17.- Metallocarboxypeptidases.
3. 4.18.- Cysteine-type carboxypeptidases.
3. 4.19.- Omega peptidases.
3. 4.21.- Serine endopeptidases.
3. 4.22.- Cysteine endopeptidases.
3. 4.23.- Aspartic endopeptidases.
3. 4.24.- Metalloendopeptidases.
3. 4.25.- Threonine endopeptidases.
3. 4.99.- Endopeptidases of unknown catalytic mechanism.
3. 5. -.- Acting on carbon-nitrogen bonds, other than peptide bonds.
3. 5. 1.- In linear amides.
3. 5. 2.- In cyclic amides.
3. 5. 3.- In linear amidines.
3. 5. 4.- In cyclic amidines.
3. 5. 5.- In nitriles.
3. 5.99.- In other compounds.
3. 6. -.- Acting on acid anhydrides.
3. 6. 1.- In phosphorous-containing anhydrides.
3. 6. 2.- In sulfonyl-containing anhydrides.
3. 6. 3.- Acting on acid anhydrides; catalyzing transmembrane movement
3. 6. 4.- Acting on acid anhydrides; involved in cellular and
3. 6. 5.- Acting on GTP; involved in cellular and subcellular movement.
3. 7. -.- Acting on carbon-carbon bonds.
3. 7. 1.- In ketonic substances.
3. 8. -.- Acting on halide bonds.
3. 8. 1.- In C-halide compounds.
3. 9. -.- Acting on phosphorus-nitrogen bonds.
3. 9. 1.- Acting on phosphorus-nitrogen bonds.
3.10. -.- Acting on sulfur-nitrogen bonds.
3.10. 1.- Acting on sulfur-nitrogen bonds.
3.11. -.- Acting on carbon-phosphorus bonds.
3.11. 1.- Acting on carbon-phosphorus bonds.
3.12. -.- Acting on sulfur-sulfur bonds.
3.12. 1.- Acting on sulfur-sulfur bonds.
3.13. -.- Acting on carbon-sulfur bonds.
3.13. 1.- Acting on carbon-sulfur bonds.
4. -. -.- Lyases.
4. 1. -.- Carbon-carbon lyases.
4. 1. 1.- Carboxy-lyases.
4. 1. 2.- Aldehyde-lyases.
4. 1. 3.- Oxo-acid-lyases.
4. 1.99.- Other carbon-carbon lyases.
4. 2. -.- Carbon-oxygen lyases.
4. 2. 1.- Hydro-lyases.
4. 2. 2.- Acting on polysaccharides.
4. 2. 3.- Acting on phosphates.
4. 2.99.- Other carbon-oxygen lyases.
4. 3. -.- Carbon-nitrogen lyases.
4. 3. 1.- Ammonia-lyases.
4. 3. 2.- Lyases acting on amides, amidines, etc.
4. 3. 3.- Amine-lyases.
4. 4. -.- Carbon-sulfur lyases.
4. 4. 1.- Carbon-sulfur lyases.
4. 5. -.- Carbon-halide lyases.
4. 5. 1.- Carbon-halide lyases.
4. 6. -.- Phosphorus-oxygen lyases.
4. 6. 1.- Phosphorus-oxygen lyases.
4.99. -.- Other lyases.
4.99. 1.- Sole sub-subclass for lyases that do not belong in the other
5. -. -.- Isomerases.
5. 1. -.- Racemases and epimerases.
5. 1. 1.- Acting on amino acids and derivatives.
5. 1. 2.- Acting on hydroxy acids and derivatives.
5. 1. 3.- Acting on carbohydrates and derivatives.
5. 1.99.- Acting on other compounds.
5. 2. -.- Cis-trans-isomerases.
5. 2. 1.- Cis-trans Isomerases.
5. 3. -.- Intramolecular oxidoreductases.
5. 3. 1.- Interconverting aldoses and ketoses, and related compounds.
5. 3. 2.- Interconverting keto- and enol- groups.
5. 3. 3.- Transposing C==C bonds.
5. 3. 4.- Transposing S-S bonds.
5. 3.99.- Other intramolecular oxidoreductases.
5. 4. -.- Intramolecular transferases (mutases).
5. 4. 1.- Transferring acyl groups.
5. 4. 2.- Phosphotransferases (phosphomutases).
5. 4. 3.- Transferring amino groups.
5. 4. 4.- Transferring hydroxy groups.
5. 4.99.- Transferring other groups.
5. 5. -.- Intramolecular lyases.
5. 5. 1.- Intramolecular lyases.
5.99. -.- Other isomerases.
5.99. 1.- Sole sub-subclass for isomerases that do not belong in the other
6. -. -.- Ligases.
6. 1. -.- Forming carbon-oxygen bonds.
6. 1. 1.- Ligases forming aminoacyl-tRNA and related compounds.
6. 2. -.- Forming carbon-sulfur bonds.
6. 2. 1.- Acid--thiol ligases.
6. 3. -.- Forming carbon-nitrogen bonds.
6. 3. 1.- Acid--ammonia (or amide) ligases (amide synthases).
6. 3. 2.- Acid--D-amino-acid ligases (peptide synthases).
6. 3. 3.- Cyclo-ligases.
6. 3. 4.- Other carbon--nitrogen ligases.
6. 3. 5.- Carbon--nitrogen ligases with glutamine as amido-N-donor.
6. 4. -.- Forming carbon-carbon bonds.
6. 4. 1.- Ligases that form carbon-carbon bonds.
6. 5. -.- Forming phosphoric ester bonds.
6. 5. 1.- Ligases that form phosphoric-ester bonds.
6. 6. -.- Forming nitrogen-metal bonds.
6. 6. 1.- Forming coordination complexes.
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