1AN8

CRYSTAL STRUCTURE OF THE STREPTOCOCCAL SUPERANTIGEN SPE-C

Summary for 1AN8

• Entry DOI: 10.2210/pdb1an8/pdb
• Descriptor: STREPTOCOCCAL PYROGENIC EXOTOXIN C (2 entities in total)
• Functional Keywords: bacterial superantigen, toxin
• Biological source: Streptococcus pyogenes
• Total number of polymer chains: 1
• Total formula weight: 24384.28

Authors

Roussel, A.,Baker, E.N. (deposition date: 1997-06-27, release date: 1998-04-29, Last modification date: 2024-02-07)

Primary citation

Roussel, A.,Anderson, B.F.,Baker, H.M.,Fraser, J.D.,Baker, E.N.
Crystal structure of the streptococcal superantigen SPE-C: dimerization and zinc binding suggest a novel mode of interaction with MHC class II molecules.
Nat.Struct.Biol., 4:635-643, 1997

PubMed Abstract: 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.

PubMed: 9253413
DOI: 10.1038/nsb0897-635

Experimental method

X-RAY DIFFRACTION (2.4 Å)