2g9h: Difference between revisions
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[[Image:2g9h.gif|left|200px]] | [[Image:2g9h.gif|left|200px]] | ||
'''Crystal Structure of Staphylococcal Enterotoxin I (SEI) in Complex with a Human MHC class II Molecule''' | {{Structure | ||
|PDB= 2g9h |SIZE=350|CAPTION= <scene name='initialview01'>2g9h</scene>, resolution 2.00Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene>, <scene name='pdbligand=EPE:4-(2-HYDROXYETHYL)-1-PIPERAZINE+ETHANESULFONIC+ACID'>EPE</scene> and <scene name='pdbligand=DIO:1,4-DIETHYLENE DIOXIDE'>DIO</scene> | |||
|ACTIVITY= | |||
|GENE= HLA-DRA ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 Homo sapiens]), HLA-DRB1 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 Homo sapiens]) | |||
}} | |||
'''Crystal Structure of Staphylococcal Enterotoxin I (SEI) in Complex with a Human MHC class II Molecule''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
2G9H is a [ | 2G9H is a [[Protein complex]] structure of sequences from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] and [http://en.wikipedia.org/wiki/Staphylococcus_aureus Staphylococcus aureus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2G9H OCA]. | ||
==Reference== | ==Reference== | ||
Crystal structure of staphylococcal enterotoxin I (SEI) in complex with a human major histocompatibility complex class II molecule., Fernandez MM, Guan R, Swaminathan CP, Malchiodi EL, Mariuzza RA, J Biol Chem. 2006 Sep 1;281(35):25356-64. Epub 2006 Jul 6. PMID:[http:// | Crystal structure of staphylococcal enterotoxin I (SEI) in complex with a human major histocompatibility complex class II molecule., Fernandez MM, Guan R, Swaminathan CP, Malchiodi EL, Mariuzza RA, J Biol Chem. 2006 Sep 1;281(35):25356-64. Epub 2006 Jul 6. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/16829512 16829512] | ||
[[Category: Homo sapiens]] | [[Category: Homo sapiens]] | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
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[[Category: zn]] | [[Category: zn]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 17:01:59 2008'' | ||
Revision as of 15:02, 20 March 2008
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| 2g9h, resolution 2.00Å | |||||||||||||
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| Ligands: | ZN, SO4, EPE and DIO | ||||||||||||
| Gene: | HLA-DRA (Homo sapiens), HLA-DRB1 (Homo sapiens) | ||||||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||||||
Crystal Structure of Staphylococcal Enterotoxin I (SEI) in Complex with a Human MHC class II Molecule
Overview
Superantigens are bacterial or viral proteins that elicit massive T cell activation through simultaneous binding to major histocompatibility complex (MHC) class II and T cell receptors. This activation results in uncontrolled release of inflammatory cytokines, causing toxic shock. A remarkable property of superantigens, which distinguishes them from T cell receptors, is their ability to interact with multiple MHC class II alleles independently of MHC-bound peptide. Previous crystallographic studies have shown that staphylococcal and streptococcal superantigens belonging to the zinc family bind to a high affinity site on the class II beta-chain. However, the basis for promiscuous MHC recognition by zinc-dependent superantigens is not obvious, because the beta-chain is polymorphic and the MHC-bound peptide forms part of the binding interface. To understand how zinc-dependent superantigens recognize MHC, we determined the crystal structure, at 2.0 A resolution, of staphylococcal enterotoxin I bound to the human class II molecule HLA-DR1 bearing a peptide from influenza hemagglutinin. Interactions between the superantigen and DR1 beta-chain are mediated by a zinc ion, and 22% of the buried surface of peptide.MHC is contributed by the peptide. Comparison of the staphylococcal enterotoxin I.peptide.DR1 structure with ones determined previously revealed that zinc-dependent superantigens achieve promiscuous binding to MHC by targeting conservatively substituted residues of the polymorphic beta-chain. Additionally, these superantigens circumvent peptide specificity by engaging MHC-bound peptides at their conformationally conserved N-terminal regions while minimizing sequence-specific interactions with peptide residues to enhance cross-reactivity.
About this Structure
2G9H is a Protein complex structure of sequences from Homo sapiens and Staphylococcus aureus. Full crystallographic information is available from OCA.
Reference
Crystal structure of staphylococcal enterotoxin I (SEI) in complex with a human major histocompatibility complex class II molecule., Fernandez MM, Guan R, Swaminathan CP, Malchiodi EL, Mariuzza RA, J Biol Chem. 2006 Sep 1;281(35):25356-64. Epub 2006 Jul 6. PMID:16829512
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