1an8

From Proteopedia

Revision as of 08:52, 30 October 2007

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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