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1sxt
From Proteopedia
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|PDB= 1sxt |SIZE=350|CAPTION= <scene name='initialview01'>1sxt</scene>, resolution 2.7Å | |PDB= 1sxt |SIZE=350|CAPTION= <scene name='initialview01'>1sxt</scene>, resolution 2.7Å | ||
|SITE= | |SITE= | ||
| - | |LIGAND= <scene name='pdbligand=ZN:ZINC ION'>ZN</scene> | + | |LIGAND= <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene> |
|ACTIVITY= | |ACTIVITY= | ||
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY= | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1sxt FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1sxt OCA], [http://www.ebi.ac.uk/pdbsum/1sxt PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1sxt RCSB]</span> | ||
}} | }} | ||
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[[Category: Staphylococcus aureus]] | [[Category: Staphylococcus aureus]] | ||
[[Category: Sundstrom, S M.]] | [[Category: Sundstrom, S M.]] | ||
| - | [[Category: ZN]] | ||
[[Category: enterotoxin]] | [[Category: enterotoxin]] | ||
[[Category: staphylococcus]] | [[Category: staphylococcus]] | ||
| Line 29: | Line 31: | ||
[[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 Sun Mar 30 23:48:26 2008'' |
Revision as of 20:48, 30 March 2008
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| , resolution 2.7Å | |||||||
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| Ligands: | |||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
STAPHYLOCOCCAL ENTEROTOXIN TYPE A (SEA) CO-CRYSTALLISED WITH ZINC
Overview
Superantigens form complexes with major histocompatibility complex (MHC) class II molecules and T-cell receptors resulting in extremely strong immunostimulatory properties. Staphylococcus aureus enterotoxin A (SEA) belongs to a subgroup of the staphylococcal superantigens that utilizes Zn2+ in the high affinity interaction with MHC class II molecules. A high affinity metal binding site was described previously in SEA co-crystallized with Cd2+ in which the metal ion was octahedrally co-ordinated, involving the N-terminal serine. We have now co-crystallized SEA with its native co-factor Zn2+ and determined its crystal structure at 2.7 A resolution. As expected for a Zn2+ ion, the co-ordination was found to be tetrahedral. Three of the ligands are located on the SEA surface on a C-terminal domain beta-sheet, while the fourth varies with the conditions. Further analysis of the zinc binding event was performed using titration microcalorimetry, which showed that SEA binds Zn2+ with an affinity of KD = 0.3 microM in an entropy driven process. The differential Zn2+ co-ordination observed here has implications for the mechanism of the SEA-MHC class II interaction.
About this Structure
1SXT is a Single protein structure of sequence from Staphylococcus aureus. Full crystallographic information is available from OCA.
Reference
The Co-crystal structure of staphylococcal enterotoxin type A with Zn2+ at 2.7 A resolution. Implications for major histocompatibility complex class II binding., Sundstrom M, Hallen D, Svensson A, Schad E, Dohlsten M, Abrahmsen L, J Biol Chem. 1996 Dec 13;271(50):32212-6. PMID:8943278
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