Active Site

Serine proteases, trypsin family, histidine active site (IPR018114)

Short name: TRYPSIN_HIS


This entry represents the histidine active site of serine proteases belonging to the MEROPS peptidase family S1 (chymotrypsin family, clan PA(S)). The catalytic activity of the serine proteases from the chymotrypsin family is provided by a charge relay system involving an aspartic acid residue hydrogen-bonded to a histidine, which itself is hydrogen-bonded to a serine. The sequences in the vicinity of the active site histidine residues are well conserved in this family of proteases [PMID: 3136396].

The chymotrypsin family is almost totally confined to animals, although trypsin-like enzymes are found in actinomycetes of the genera Streptomyces and Saccharopolyspora, and in the fungus Fusarium oxysporum [PMID: 7845208]. The enzymes are inherently secreted, being synthesised with a signal peptide that targets them to the secretory pathway. Animal enzymes are either secreted directly, packaged into vesicles for regulated secretion, or are retained in leukocyte granules [PMID: 7845208].

GO terms

Biological Process

GO:0006508 proteolysis

Molecular Function

GO:0004252 serine-type endopeptidase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PROSITE patterns