Enzyme Nomenclature. Recommendations
EC 4.3.1 Ammonia-Lyases
EC 4.3.2 Lyases Acting on Amides, Amidines, etc.
EC 4.3.3 Amine-Lyases
EC 4.3.99 Other Carbon-Nitrogen Lyases
This subclass contains the enzymes that release ammonia or one of its derivatives, with the formation of a double bond or ring. Some catalyse the actual elimination of the ammonia, amine or amide, e.g.
Others, however, catalyse elimination of another component, e.g. water, which is followed by spontaneous reactions that lead to breakage of the C-N bond, e.g.
as in EC 188.8.131.52 (L-serine ammonia-lyase), so that the overall reaction is
i.e., an elimination with rearrangement.