The Staphostatin-Staphopain Complex: A FORWARD BINDING INHIBITOR IN COMPLEX WITH ITS TARGET CYSTEINE PROTEASE.Filipek, R., Rzychon, M., Oleksy, A., Gruca, M., Dubin, A., Potempa, J., Bochtler, M.
(2003) J.Biol.Chem. 278: 40959-40966
- PubMed: 12874290
- DOI: 10.1074/jbc.M302926200
- PubMed Abstract:
- Staphostatins: an expanding new group of proteinase inhibitors with a unique specificity for the regulation of staphopains, Staphylococcus spp. cysteine proteinases
Rzychon, M.,Sabat, A.,Kosowska, K.,Potempa, J.,Dubin, A.
(2003) MOL.MICROBIOL. 49: 1051
- Identification of a novel maturation mechanism and restricted substrate specificity for the SspB cysteine protease of Staphylococcus aureus
Massimi, I.,Park, E.,Rice, K.,Muller-Esterl, W.,Sauder, D.,McGavin, M.J.
(2002) J.Biol.Chem. 277: 41770
- Staphostatins resemble lipocalins, not cystatins in fold.
Rzychon, M.,Filipek, R.,Sabat, A.,Kosowska, K.,Dubin, A.,Potempa, J.,Bochtler, M.
(2003) Protein Sci. 12: 2252
Staphostatins are the endogenous inhibitors of the major secreted cysteine proteases of Staphylococcus aureus, the staphopains. Our recent crystal structure of staphostatin B has shown that this inhibitor forms a mixed, eight-stranded beta-barrel wit ...
Staphostatins are the endogenous inhibitors of the major secreted cysteine proteases of Staphylococcus aureus, the staphopains. Our recent crystal structure of staphostatin B has shown that this inhibitor forms a mixed, eight-stranded beta-barrel with statistically significant similarity to lipocalins, but not to cystatins. We now present the 1.8-A crystal structure of staphostatin B in complex with an inactive mutant of its target protease. The complex is held together through extensive interactions and buries a total surface area of 2300 A2. Unexpectedly for a cysteine protease inhibitor, staphostatin B binds to staphopain B in an almost substrate-like manner. The inhibitor polypeptide chain runs through the protease active site cleft in the forward direction, with residues IG-TS in P2 to P2' positions. Both in the free and complexed forms, the P1 glycine residue of the inhibitor is in a main chain conformation only accessible to glycines. Mutations in this residue lead to a loss of affinity of the inhibitor for protease and convert the inhibitor into a substrate.
International Institute of Molecular and Cell Biology, ul Trojdena 4, 02-109 Warsaw, Poland.