1an8
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| , resolution 2.4Å | |||||||
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| Sites: | and | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
CRYSTAL STRUCTURE OF THE STREPTOCOCCAL SUPERANTIGEN SPE-C
OverviewOverview
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 StructureAbout this Structure
1AN8 is a Single protein structure of sequence from Streptococcus pyogenes. Full crystallographic information is available from OCA.
ReferenceReference
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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