Crystal structure of staphylococcal enterotoxin G (SEG) in complex with a mouse T-cell receptor {beta} chain.

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TitleCrystal structure of staphylococcal enterotoxin G (SEG) in complex with a mouse T-cell receptor {beta} chain.
Publication TypeJournal Article
Year of Publication2011
AuthorsFernández, MM, Cho, S, De Marzi, MC, Kerzic, MC, Robinson, H, Mariuzza, RA, Malchiodi, EL
JournalJ Biol Chem
Volume286
Issue2
Pagination1189-95
Date Published2011 Jan 14
ISSN1083-351X
KeywordsAnimals, Binding Sites, Cells, Cultured, Crystallography, X-Ray, Enterotoxins, Escherichia coli, Mice, Protein Binding, Protein Structure, Tertiary, Receptors, Antigen, T-Cell, alpha-beta, Staphylococcus aureus, Structure-Activity Relationship, Superantigens
Abstract

Superantigens (SAgs) are bacterial or viral toxins that bind MHC class II (MHC-II) molecules and T-cell receptor (TCR) in a nonconventional manner, inducing T-cell activation that leads to inflammatory cytokine production, which may result in acute toxic shock. In addition, the emerging threat of purpura fulminans and community-associated meticillin-resistant Staphylococcus aureus emphasizes the importance of a better characterization of SAg binding to their natural ligands that may allow the development of reagents to neutralize their action. The three-dimensional structure of the complex between a mouse TCR β chain (mVβ8.2) and staphylococcal enterotoxin G (SEG) at 2.0 Å resolution revealed a binding site that does not conserve the "hot spots" present in mVβ8.2-SEC2, mVβ8.2-SEC3, mVβ8.2-SEB, and mVβ8.2-SPEA complexes. Analysis of the mVβ8.2-SEG interface allowed us to explain the higher affinity of this complex compared with the others, which may account for the early activation of T-cells bearing mVβ8.2 by SEG. This mode of interaction between SEG and mVβ8.2 could be an adaptive advantage to bestow on the pathogen a faster rate of colonization of the host.

DOI10.1074/jbc.M110.142471
Alternate JournalJ. Biol. Chem.
PubMed ID21059660
PubMed Central IDPMC3020726
Grant ListAI073654 / AI / NIAID NIH HHS / United States
AI36900 / AI / NIAID NIH HHS / United States
TW007972 / TW / FIC NIH HHS / United States