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Structure of the Mature Streptococcal Cysteine Protease Exotoxin mSpeB in Its Active Dimeric Form

Olsen, Johan G.; Dagil, Robert; Niclasen, Louise Meinert; Sørensen, Ole E LU and Kragelund, Birthe B. (2009) In Journal of Molecular Biology 393(3). p.693-703
Abstract
Invasive infections of Streptococcus pyogenes are dependent on the cysteine protease streptococcal pyrogenic exotoxin B. Previous structures of the enzyme have not disclosed the proper active-site configuration. Here, the crystal structure of the mature enzyme is presented to 1.55 angstrom, disclosing a homodimer. A serine from one subunit inserts into the active site of the other to donate to the oxyanion hole and coordinates the ligand proximal to the active-site cysteine. Dimerization. is unique to the mature form and is clearly a prerequisite for catalysis. The present structure supports a tripartite switch system that is triggered upon dimerization and substrate binding: (1) liberation of the active-site histidine from an inactive... (More)
Invasive infections of Streptococcus pyogenes are dependent on the cysteine protease streptococcal pyrogenic exotoxin B. Previous structures of the enzyme have not disclosed the proper active-site configuration. Here, the crystal structure of the mature enzyme is presented to 1.55 angstrom, disclosing a homodimer. A serine from one subunit inserts into the active site of the other to donate to the oxyanion hole and coordinates the ligand proximal to the active-site cysteine. Dimerization. is unique to the mature form and is clearly a prerequisite for catalysis. The present structure supports a tripartite switch system that is triggered upon dimerization and substrate binding: (1) liberation of the active-site histidine from an inactive configuration, (2) relocation of residues blocking the substrate binding pockets and (3) repositioning of two active-site tryptophans to settle in the active configuration. Based on the present structure, the active site of clan CA cysteine proteases is expanded and a detailed mechanism of the deacylation mechanism is proposed. The results may have applications for the development of protease inhibitors specific to bacterial cysteine proteases. (c) 2009 Elsevier Ltd. All rights reserved. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
loop, Velcro, Streptococcus pyogenes, papain, catalytic mechanism, exotoxin
in
Journal of Molecular Biology
volume
393
issue
3
pages
693 - 703
publisher
Elsevier
external identifiers
  • wos:000271167400011
  • scopus:70349783818
ISSN
1089-8638
DOI
10.1016/j.jmb.2009.08.046
language
English
LU publication?
yes
id
15789021-c424-4ef4-8e47-8050684c3164 (old id 1505357)
date added to LUP
2009-11-24 11:54:53
date last changed
2017-01-01 05:22:13
@article{15789021-c424-4ef4-8e47-8050684c3164,
  abstract     = {Invasive infections of Streptococcus pyogenes are dependent on the cysteine protease streptococcal pyrogenic exotoxin B. Previous structures of the enzyme have not disclosed the proper active-site configuration. Here, the crystal structure of the mature enzyme is presented to 1.55 angstrom, disclosing a homodimer. A serine from one subunit inserts into the active site of the other to donate to the oxyanion hole and coordinates the ligand proximal to the active-site cysteine. Dimerization. is unique to the mature form and is clearly a prerequisite for catalysis. The present structure supports a tripartite switch system that is triggered upon dimerization and substrate binding: (1) liberation of the active-site histidine from an inactive configuration, (2) relocation of residues blocking the substrate binding pockets and (3) repositioning of two active-site tryptophans to settle in the active configuration. Based on the present structure, the active site of clan CA cysteine proteases is expanded and a detailed mechanism of the deacylation mechanism is proposed. The results may have applications for the development of protease inhibitors specific to bacterial cysteine proteases. (c) 2009 Elsevier Ltd. All rights reserved.},
  author       = {Olsen, Johan G. and Dagil, Robert and Niclasen, Louise Meinert and Sørensen, Ole E and Kragelund, Birthe B.},
  issn         = {1089-8638},
  keyword      = {loop,Velcro,Streptococcus pyogenes,papain,catalytic mechanism,exotoxin},
  language     = {eng},
  number       = {3},
  pages        = {693--703},
  publisher    = {Elsevier},
  series       = {Journal of Molecular Biology},
  title        = {Structure of the Mature Streptococcal Cysteine Protease Exotoxin mSpeB in Its Active Dimeric Form},
  url          = {http://dx.doi.org/10.1016/j.jmb.2009.08.046},
  volume       = {393},
  year         = {2009},
}