_EC 3.4.25.- Threonine endopeptidases. 128 PDB entries  
EC 3.-.-.- Hydrolases. [21,057 PDB entries]
EC 3.4.-.- Acting on peptide bonds (peptide hydrolases). [6,846 PDB entries]
EC 3.4.25.- Threonine endopeptidases. [128 PDB entries]    
EC 3.4.25.1 Proteasome endopeptidase complex. [110 PDB entries]
EC 3.4.25.2 HslU--HslV peptidase. [18 PDB entries]