Proline iminopeptidases belong to serine peptidase family S33. They catalyse the removal of an N-terminal proline residue from peptides with high specificity.
The bacterial Xanthomonas citri enzyme is thought to be involved in proline metabolism and sensitivity to ascamycin (has ascamycin dealanylating activity).
The archaeal Tricorn> protease interacting factor 1 (F1) from is responsible for the cleavage of hydrophobic peptides which are generated by tricorn peptidase. It cleaves H-Pro-AMC as well as a wide spectrum of amino acid substrates and including several peptide substrates without a proline at the N-terminus.
The mechanism of the serine proteases is commonly believed to be among the best understood of all enzymes. As their name suggests, they are involved in hydrolysis of proteins using a serine nucleophile.
Defined by 5 residues: GLY:A-43SER:A-110TRP:A-111ASP:A-266HIS:A-294