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PROSITE documentation PDOC00126 |
Eukaryotic thiol proteases (EC 3.4.22.-) [1] are a family of proteolytic enzymes which contain an active site cysteine. Catalysis proceeds through a thioester intermediate and is facilitated by a nearby histidine side chain; an asparagine completes the essential catalytic triad. The proteases which are currently known to belong to this family are listed below (references are only provided for recently determined sequences).
Two bacterial peptidases are also part of this family:
Three other proteins are structurally related to this family, but may have lost their proteolytic activity.
The sequences around the three active site residues are well conserved and can be used as signature patterns.
Note:The residue in position 4 of the pattern is almost always cysteine; the only exceptions are calpains (Leu), bleomycin hydrolase (Ser) and yeast YCP1 (Ser).
Note:The residue in position 5 of the pattern is always Gly except in papaya protease IV where it is Glu.
Consensus pattern:[LIVMGSTAN]-{IEVK}-H-[GSACE]-[LIVM]-{GPSI}-[LIVMAT](2)-G- {SLAG}-[GSADNH] [H is the active site residue]
Sequences known to belong to this class detected by the pattern:ALL, except for calpains, P34 and tpr.
Other sequence(s) detected in Swiss-Prot:146.
Consensus pattern:[FYCH]-[WI]-[LIVT]-x-[KRQAG]-N-[ST]-W-x(3)-[FYW]-G-x(2)-G- [LFYW]-[LIVMFYG]-x-[LIVMF] [N is the active site residue]
Sequences known to belong to this class detected by the pattern:ALL, except for calpains, bromelain, yeast BLH1, tomato low-temperature induced protease, cathepsin O, pepC and tpr.
Other sequence(s) detected in Swiss-Prot:NONE.
Note:These proteins belong to family C1 (papain-type) and C2 (calpains) in the classification of peptidases [7,E1].
Expert(s) to contact by email: Last update:April 2006 / Patterns revised.
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PROSITE methods (with tools and information) covered by this documentation:
1 | Authors | Dufour E. |
Title | Sequence homologies, hydrophobic profiles and secondary structures of cathepsins B, H and L: comparison with papain and actinidin. | |
Source | Biochimie 70:1335-1342(1988). | |
PubMed ID | 3148320 |
2 | Authors | Kirschke H. Barrett A.J. Rawlings N.D. |
Source | Protein Prof. 2:1587-1643(1995). |
3 | Authors | Shi G.-P. Chapman H.A. Bhairi S.M. DeLeeuw C. Reddy V.Y. Weiss S.J. |
Title | Molecular cloning of human cathepsin O, a novel endoproteinase and homologue of rabbit OC2. | |
Source | FEBS Lett. 357:129-134(1995). | |
PubMed ID | 7805878 |
4 | Authors | Velasco G. Ferrando A.A. Puente X.S. Sanchez L.M. Lopez-Otin C. |
Title | Human cathepsin O. Molecular cloning from a breast carcinoma, production of the active enzyme in Escherichia coli, and expression analysis in human tissues. | |
Source | J. Biol. Chem. 269:27136-27142(1994). | |
PubMed ID | 7929457 |
5 | Authors | Chapot-Chartier M.P. Nardi M. Chopin M.C. Chopin A. Gripon J.C. |
Source | Appl. Environ. Microbiol. 59:330-333(1993). |
6 | Authors | Higgins D.G. McConnell D.J. Sharp P.M. |
Title | Malarial proteinase? | |
Source | Nature 340:604-604(1989). | |
PubMed ID | 2671749 | |
DOI | 10.1038/340604a0 |
7 | Authors | Rawlings N.D. Barrett A.J. |
Title | Families of cysteine peptidases. | |
Source | Methods Enzymol. 244:461-486(1994). | |
PubMed ID | 7845226 |
E1 | Title | https://www.uniprot.org/docs/peptidas |