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1an8
From Proteopedia
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Revision as of 13:44, 5 November 2007
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CRYSTAL STRUCTURE OF THE STREPTOCOCCAL SUPERANTIGEN SPE-C
Overview
Bacterial superantigens are small proteins that have a very potent, stimulatory effect on T lymphocytes through their ability to bind to both, MHC class II molecules and T-cell receptors. We have determined the, three-dimensional structure of a Streptococcal superantigen, SPE-C, at 2.4, A resolution. The structure shows that SPE-C has the usual superantigen, fold, but that the surface that forms a generic, low-affinity MHC-binding, site in other superantigens is here used to create a SPE-C dimer. Instead, MHC class II binding occurs through a zinc binding site that is analogous, to a similar site in staphylococcal enterotoxin A. Consideration of the, SPE-C dimer suggests a novel mechanism for promotion of MHC aggregation, and T-cell activation.
About this Structure
1AN8 is a Single protein structure of sequence from Streptococcus pyogenes. Structure known Active Sites: ZNA and ZNB. Full crystallographic information is available from OCA.
Reference
Crystal structure of the streptococcal superantigen SPE-C: dimerization and zinc binding suggest a novel mode of interaction with MHC class II molecules., Roussel A, Anderson BF, Baker HM, Fraser JD, Baker EN, Nat Struct Biol. 1997 Aug;4(8):635-43. PMID:9253413
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