_EC 3.-.-.- Hydrolases. 20,909 PDB entries  
EC 3.-.-.-
The hydrolases catalyse the hydrolytic cleavage of C-O, C-N, C-C and some other bonds, including phosphoric anhydride bonds.

The E.C. classification for these enzymes generally classifies them firstly by the nature of the bond hydrolysed, then by the nature of the substrate, and lastly by the enzyme.

Although the systematic name always includes hydrolase, the recommended name is, in many cases, formed by the name of the substrate with the suffix -ase. It is understood that the name of the substrate with this suffix means a hydrolytic enzyme.

See also: [IUBMB] (Enzyme Nomenclature)

EC 3.-.-.- Hydrolases. [20,909 PDB entries]    
EC 3.1.-.- Acting on ester bonds. [5,941 PDB entries]
EC 3.2.-.- Glycosylases. [4,021 PDB entries]
EC 3.3.-.- Acting on ether bonds. [121 PDB entries]
EC 3.4.-.- Acting on peptide bonds (peptide hydrolases). [6,824 PDB entries]
EC 3.5.-.- Acting on carbon-nitrogen bonds, other than peptide bonds. [1,657 PDB entries]
EC 3.6.-.- Acting on acid anhydrides. [2,190 PDB entries]
EC 3.7.-.- Acting on carbon-carbon bonds. [39 PDB entries]
EC 3.8.-.- Acting on halide bonds. [94 PDB entries]
EC 3.9.-.- Acting on phosphorus-nitrogen bonds. [-]
EC 3.10.-.- Acting on sulfur-nitrogen bonds. [2 PDB entries]
EC 3.11.-.- Acting on carbon-phosphorus bonds. [13 PDB entries]
EC 3.12.-.- Acting on sulfur-sulfur bonds. [-]
EC 3.13.-.- Acting on carbon-sulfur bonds. [7 PDB entries]

[-] signifies that there are no PDB entries for the given enzyme subclass