1. Oxidoreductases

 2. Transferases

   2.1  Transferring one-carbon groups

     2.1.1  Methyltransferases

     2.1.2  Hydroxymethyl-, formyl- and related transferases

       2.1.2.1  glycine hydroxymethyltransferase

       2.1.2.2  phosphoribosylglycinamide formyltransferase 1

       2.1.2.3  phosphoribosylaminoimidazolecarboxamide formyltransferase

       2.1.2.4  glycine formimidoyltransferase

       2.1.2.5  glutamate formimidoyltransferase

       2.1.2.7  D-alanine 2-hydroxymethyltransferase

       2.1.2.8  deoxycytidylate 5-hydroxymethyltransferase

       2.1.2.9  methionyl-tRNA formyltransferase

       2.1.2.10  aminomethyltransferase

       2.1.2.11  3-methyl-2-oxobutanoate hydroxymethyltransferase

       2.1.2.13  UDP-4-amino-4-deoxy-L-arabinose formyltransferase

       2.1.2.14  GDP-perosamine N-formyltransferase

     2.1.3  Carboxy- and carbamoyltransferases

     2.1.4  Amidinotransferases

     2.1.5  Methylenetransferases

   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

   2.7  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