1. Oxidoreductases

 2. Transferases

 3. Hydrolases

   3.1  Acting on ester bonds

     3.1.1  Carboxylic-ester hydrolases

     3.1.2  Thioester hydrolases

     3.1.3  Phosphoric-monoester hydrolases

     3.1.4  Phosphoric-diester hydrolases

       3.1.4.1  phosphodiesterase I

       3.1.4.2  glycerophosphocholine phosphodiesterase

       3.1.4.3  phospholipase C

       3.1.4.4  phospholipase D

       3.1.4.11  phosphoinositide phospholipase C

       3.1.4.12  sphingomyelin phosphodiesterase

       3.1.4.13  serine-ethanolaminephosphate phosphodiesterase

       3.1.4.14  [acyl-carrier-protein] phosphodiesterase

       3.1.4.16  2',3'-cyclic-nucleotide 2'-phosphodiesterase

       3.1.4.17  3',5'-cyclic-nucleotide phosphodiesterase

       3.1.4.35  3',5'-cyclic-GMP phosphodiesterase

       3.1.4.37  2',3'-cyclic-nucleotide 3'-phosphodiesterase

       3.1.4.38  glycerophosphocholine cholinephosphodiesterase

       3.1.4.39  alkylglycerophosphoethanolamine phosphodiesterase

       3.1.4.40  CMP-N-acylneuraminate phosphodiesterase

       3.1.4.41  sphingomyelin phosphodiesterase D

       3.1.4.42  glycerol-1,2-cyclic-phosphate 2-phosphodiesterase

       3.1.4.43  glycerophosphoinositol inositolphosphodiesterase

       3.1.4.44  glycerophosphoinositol glycerophosphodiesterase

       3.1.4.45  N-acetylglucosamine-1-phosphodiester alpha-N-acetylglucosaminidase

       3.1.4.46  glycerophosphodiester phosphodiesterase

       3.1.4.48  dolichylphosphate-glucose phosphodiesterase

       3.1.4.49  dolichylphosphate-mannose phosphodiesterase

       3.1.4.50  glycosylphosphatidylinositol phospholipase D

       3.1.4.51  glucose-1-phospho-D-mannosylglycoprotein phosphodiesterase

       3.1.4.52  cyclic-guanylate-specific phosphodiesterase

       3.1.4.53  3',5'-cyclic-AMP phosphodiesterase

       3.1.4.54  N-acetylphosphatidylethanolamine-hydrolysing phospholipase D

       3.1.4.55  phosphoribosyl 1,2-cyclic phosphate phosphodiesterase

       3.1.4.56  7,8-dihydroneopterin 2',3'-cyclic phosphate phosphodiesterase

       3.1.4.57  phosphoribosyl 1,2-cyclic phosphate 1,2-diphosphodiesterase

       3.1.4.58  RNA 2',3'-cyclic 3'-phosphodiesterase

       3.1.4.59  cyclic-di-AMP phosphodiesterase

       3.1.4.60  pApA phosphodiesterase

       3.1.4.61  cyclic 2,3-diphosphoglycerate hydrolase

     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

     3.1.12  Exodeoxyribonucleases producing 3'-phosphomonoesters

     3.1.13  Exoribonucleases producing 5'-phosphomonoesters

     3.1.14  Exoribonucleases producing 3'-phosphomonoesters

     3.1.15  Exonucleases that are active with either ribo- or deoxyribonucleic acids and produce 5'-phosphomonoesters

     3.1.16  Exonucleases that are active with either ribo- or deoxyribonucleic acids and produce 3'-phosphomonoesters

     3.1.21  Endodeoxyribonucleases producing 5'-phosphomonoesters

     3.1.22  Endodeoxyribonucleases producing 3'-phosphomonoesters

     3.1.25  Site-specific endodeoxyribonucleases that are specific for altered bases

     3.1.26  Endoribonucleases producing 5'-phosphomonoesters

     3.1.27  Endoribonucleases producing 3'-phosphomonoesters

     3.1.30  Endoribonucleases that are active with either ribo- or deoxyribonucleic acids and produce 5'-phosphomonoesters

     3.1.31  Endoribonucleases that are active with either ribo- or deoxyribonucleic acids and produce 3'-phosphomonoesters

   3.2  Glycosylases

   3.3  Acting on ether bonds

   3.4  Acting on peptide bonds (peptidases)

   3.5  Acting on carbon-nitrogen bonds, other than peptide bonds

   3.6  Acting on acid anhydrides

   3.7  Acting on carbon-carbon bonds

   3.8  Acting on halide bonds

   3.9  Acting on phosphorus-nitrogen bonds

   3.10  Acting on sulfur-nitrogen bonds

   3.11  Acting on carbon-phosphorus bonds

   3.12  Acting on sulfur-sulfur bonds

   3.13  Acting on carbon-sulfur bonds

 4. Lyases

 5. Isomerases

 6. Ligases

 7. Translocases