1. Oxidoreductases

 2. Transferases

   2.1  Transferring one-carbon groups

   2.2  Transferring aldehyde or ketonic groups

   2.3  Acyltransferases

   2.4  Glycosyltransferases

     2.4.1  Hexosyltransferases

     2.4.2  Pentosyltransferases

     2.4.3  Sialyltransferases

       2.4.3.1  beta-galactoside alpha-(2,6)-sialyltransferase

       2.4.3.2  beta-D-galactosyl-(1->3)-N-acetyl-beta-D-galactosaminide alpha-2,3-sialyltransferase

       2.4.3.3  alpha-N-acetylgalactosaminide alpha-2,6-sialyltransferase

       2.4.3.4  beta-galactoside alpha-2,3-sialyltransferase

       2.4.3.5  galactosyldiacylglycerol alpha-2,3-sialyltransferase

       2.4.3.6  N-acetyllactosaminide alpha-2,3-sialyltransferase

       2.4.3.7  alpha-N-acetylneuraminyl-2,3-beta-galactosyl-1,3-N-acetylgalactosaminide 6-alpha-sialyltransferase

       2.4.3.8  alpha-N-acetylneuraminate alpha-2,8-sialyltransferase

       2.4.3.9  lactosylceramide alpha-2,3-sialyltransferase

       2.4.3.10  N-acetylglucosaminide alpha-(2,6)-sialyltransferase

     2.4.99  Transferring other glycosyl groups

   2.5  Transferring alkyl or aryl groups, other than methyl groups

   2.6  Transferring nitrogenous groups

   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