Active Site

Serine proteases, trypsin family, serine active site (IPR033116)

Short name: TRYPSIN_SER


The catalytic activity of the serine proteases from the trypsin 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 serine and histidine residues are well conserved in this family of proteases [PMID: 3136396]. A partial list of proteases known to belong to the trypsin family is shown below.

  • Acrosin.
  • Blood coagulation factors VII, IX, X, XI and XII, thrombin, plasminogen, and protein C.
  • Cathepsin G.
  • Chymotrypsins.
  • Complement components C1r, C1s, C2, and complement factors B, D and I.
  • Complement-activating component of RA-reactive factor.
  • Cytotoxic cell proteases (granzymes A to H).
  • Duodenase I.
  • Elastases 1, 2, 3A, 3B (protease E), leukocyte (medullasin).
  • Enterokinase (EC (enteropeptidase).
  • Hepatocyte growth factor activator.
  • Hepsin.
  • Glandular (tissue) kallikreins (including EGF-binding protein types A, B, and C, NGF-gamma chain, gamma-renin, prostate specific antigen (PSA) and tonin).
  • Plasma kallikrein.
  • Mast cell proteases (MCP) 1 (chymase) to 8.
  • Myeloblastin (proteinase 3) (Wegener's autoantigen).
  • Plasminogen activators (urokinase-type, and tissue-type).
  • Trypsins I, II, III, and IV.
  • Tryptases.
  • Snake venom proteases such as ancrod, batroxobin, cerastobin, flavoxobin,and protein C activator.
  • Collagenase from common cattle grub and collagenolytic protease from Atlantic sand fiddler crab.
  • Apolipoprotein(a).
  • Blood fluke cercarial protease.
  • Drosophila trypsin like proteases: alpha, easter, snake-locus.
  • Drosophila protease stubble (gene sb).
  • Major mite fecal allergen Der p III.

In addition to proteins from eukaryotic species listed above, are a number of bacterial family members, including:

  • Achromobacter lyticus protease I.
  • Lysobacter alpha-lytic protease.
  • Streptogrisin A and B (Streptomyces proteases A and B).
  • Streptomyces griseus glutamyl endopeptidase II.
  • Streptomyces fradiae proteases 1 and 2.

This entry represents the serine active site of serine proteases belonging to peptidase family S1.

Contributing signatures

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