Publication Abstract from PubMed
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 beta chain (mVbeta8.2) and staphylococcal enterotoxin G (SEG) at 2.0 A resolution revealed a binding site that does not conserve the "hot spots" present in mVbeta8.2-SEC2, mVbeta8.2-SEC3, mVbeta8.2-SEB, and mVbeta8.2-SPEA complexes. Analysis of the mVbeta8.2-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 mVbeta8.2 by SEG. This mode of interaction between SEG and mVbeta8.2 could be an adaptive advantage to bestow on the pathogen a faster rate of colonization of the host.
Crystal structure of staphylococcal enterotoxin G (SEG) in complex with a mouse T-cell receptor {beta} chain.,Fernandez MM, Cho S, De Marzi MC, Kerzic MC, Robinson H, Mariuzza RA, Malchiodi EL J Biol Chem. 2011 Jan 14;286(2):1189-95. Epub 2010 Nov 8. PMID:21059660[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
