1an8
From Proteopedia
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==Overview== | ==Overview== | ||
| - | Bacterial superantigens are small proteins that have a very potent | + | 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== | ==About this Structure== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Streptococcus pyogenes]] | [[Category: Streptococcus pyogenes]] | ||
| - | [[Category: Baker, E | + | [[Category: Baker, E N.]] |
[[Category: Roussel, A.]] | [[Category: Roussel, A.]] | ||
[[Category: bacterial superantigen]] | [[Category: bacterial superantigen]] | ||
[[Category: toxin]] | [[Category: toxin]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:46:18 2008'' |
Revision as of 09:46, 21 February 2008
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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. Known structural/functional Sites: and . 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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