_EC 4.3.-.- Carbon-nitrogen lyases. 543 PDB entries  
EC 4.-.-.- Lyases. [10,244 PDB entries]
EC 4.3.-.- Carbon-nitrogen lyases. [543 PDB entries]
EC 4.3.1.- Ammonia-lyases. [178 PDB entries]
EC 4.3.2.- Lyases acting on amides, amidines, etc. [158 PDB entries]
EC 4.3.3.- Amine-lyases. [189 PDB entries]
EC 4.3.99.- Other carbon-nitrogen lyases. [18 PDB entries]