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PROSITE documentation PDOC51276PfpI endopeptidase domain profile
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PURL: https://purl.expasy.org/prosite/documentation/PDOC51276
Pyrococcus furiosus protease I (PfpI) (EC 3.2.-.-) is an intracellular cysteine peptidase, characterized by its stability and proposed to represent the predominant proteolytic activity of this thermophilic archaebacterium. Pfpi-like proteins have been found in bacteria, archaea, in some plants and in amoebas.
The structure of P. horikoshii PfpI shows an α/β sandwich fold, which consists of a central β sheet flanked by two helices and two strands on one side, and by six helices and two strands on the other side (see <PDB:1G2I>). The fold resembles that of glutamine amidotransferases (GATase) of class I, which are characterized by a conserved Cys-His-Glu active site (see <PDOC00405>). The catalytically essential cysteine is located at a nucleophile elbow. PfpI forms a hexameric structure and the active sites are formed at the interfaces between three pairs of monomers. Cys and His form a triad with a glutamate residue from an adjacent monomer [1]. Pfpi endopeptidases belong to the peptidase C56 family, which is classified with the peptidase C26 γ-glutamyl hydrolases (see <PDOC51275>) in the clan PC(C) [E1,E2]. Other peptidase C56 family proteins are structurally and functionally different [2], e.g. human DJ-1 creates a hydrophobic patch at the molecular interface instead of completing the catalytic triad, while E. coli chaperone HSP31 forms a Cys-His-Asp triad.
Some proteins known to contain a PfpI endopeptidase domain:
- Pyrococcus furiosus intracellular protease 1 (PfpI), an ATP-independent, highly thermically and chemically stable endopeptidase.
- Pyrococcus horikoshii intracellular protease 1 (PfpI/PH1704).
- Bacillus subtilis general stress protein 18 (GSP18).
- Escherichia coli protein yhbO.
The profile we developed covers the entire PfpI endopeptidase domain.
Note:These proteins belong to family C56 in the classification of peptidases [E1,E2].
Note:The PfpI endopeptidase domain profile is in competition with a profile of a related domain, i.e. GATase type 1 (see <PDOC00405>).
Last update:December 2006 / First entry.
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PROSITE method (with tools and information) covered by this documentation:
| 1 | Authors | Du X. Choi I.-G. Kim R. Wang W. Jancarik J. Yokota H. Kim S.-H. |
| Title | Crystal structure of an intracellular protease from Pyrococcus horikoshii at 2-A resolution. | |
| Source | Proc. Natl. Acad. Sci. U.S.A. 97:14079-14084(2000). | |
| PubMed ID | 11114201 | |
| DOI | 10.1073/pnas.260503597 |
| 2 | Authors | Bandyopadhyay S. Cookson M.R. |
| Title | Evolutionary and functional relationships within the DJ1 superfamily. | |
| Source | BMC Evol. Biol. 4:6-6(2004). | |
| PubMed ID | 15070401 | |
| DOI | 10.1186/1471-2148-4-6 |
| E1 | Title | https://www.uniprot.org/docs/peptidas |
| E2 | Title | https://www.ebi.ac.uk/merops/cgi-bin/famsum?family=C56 |
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