1. Oxidoreductases

 2. Transferases

 3. Hydrolases

 4. Lyases

   4.1  Carbon-carbon lyases

   4.2  Carbon-oxygen lyases

   4.3  Carbon-nitrogen lyases

   4.4  Carbon-sulfur lyases

   4.5  Carbon-halide lyases

   4.6  Phosphorus-oxygen lyases

   4.7  carbon-phosphorus lyases

   4.8  Nitrogen-oxygen lyases

   4.98  ATP-independent chelatases

   4.99  Other lyases

     4.99.1  Sole sub-subclass for lyases that do not belong in the other subclasses

       4.99.1.2  alkylmercury lyase

       4.99.1.3  sirohydrochlorin cobaltochelatase

       4.99.1.4  sirohydrochlorin ferrochelatase

       4.99.1.8  heme ligase

       4.99.1.9  coproporphyrin ferrochelatase

       4.99.1.10  magnesium dechelatase

       4.99.1.11  sirohydrochlorin nickelchelatase

       4.99.1.12  pyridinium-3,5-bisthiocarboxylic acid mononucleotide nickel chelatase

 5. Isomerases

 6. Ligases

 7. Translocases