_EC 3.5.-.- Acting on carbon-nitrogen bonds, other than peptide bonds. 1,666 PDB entries  
EC 3.-.-.- Hydrolases. [21,057 PDB entries]
EC 3.5.-.- Acting on carbon-nitrogen bonds, other than peptide bonds. [1,666 PDB entries]    
EC 3.5.1.- In linear amides. [596 PDB entries]
EC 3.5.2.- In cyclic amides. [620 PDB entries]
EC 3.5.3.- In linear amidines. [165 PDB entries]
EC 3.5.4.- In cyclic amidines. [234 PDB entries]
EC 3.5.5.- In nitriles. [10 PDB entries]
EC 3.5.99.- In other compounds. [41 PDB entries]