1. Oxidoreductases

 2. Transferases

   2.1  Transferring one-carbon groups

   2.2  Transferring aldehyde or ketonic groups

   2.3  Acyltransferases

   2.4  Glycosyltransferases

   2.5  Transferring alkyl or aryl groups, other than methyl groups

   2.6  Transferring nitrogenous groups

     2.6.1  Transaminases

     2.6.3  Oximinotransferases

     2.6.99  Transferring other nitrogenous groups

       2.6.99.1  dATP(dGTP)---DNA purinetransferase

       2.6.99.2  pyridoxine 5'-phosphate synthase

       2.6.99.3  O-ureido-L-serine synthase

   2.7  Transferring phosphorus-containing groups

   2.8  Transferring sulfur-containing groups

   2.9  Transferring selenium-containing groups

   2.10  Transferring molybdenum- or tungsten-containing groups

 3. Hydrolases

 4. Lyases

 5. Isomerases

 6. Ligases

 7. Translocases