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| [[Image:1et9.jpg|left|200px]]
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| <!-- | | ==CRYSTAL STRUCTURE OF THE SUPERANTIGEN SPE-H FROM STREPTOCOCCUS PYOGENES== |
| The line below this paragraph, containing "STRUCTURE_1et9", creates the "Structure Box" on the page.
| | <StructureSection load='1et9' size='340' side='right'caption='[[1et9]], [[Resolution|resolution]] 1.90Å' scene=''> |
| You may change the PDB parameter (which sets the PDB file loaded into the applet)
| | == Structural highlights == |
| or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
| | <table><tr><td colspan='2'>[[1et9]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Streptococcus_pyogenes Streptococcus pyogenes]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1ET9 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1ET9 FirstGlance]. <br> |
| or leave the SCENE parameter empty for the default display.
| | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.9Å</td></tr> |
| -->
| | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1et9 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1et9 OCA], [https://pdbe.org/1et9 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1et9 RCSB], [https://www.ebi.ac.uk/pdbsum/1et9 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1et9 ProSAT]</span></td></tr> |
| {{STRUCTURE_1et9| PDB=1et9 | SCENE= }}
| | </table> |
| | == Function == |
| | [https://www.uniprot.org/uniprot/SPEH_STRPY SPEH_STRPY] Mitogenic for human peripheral blood lymphocytes. |
| | == Evolutionary Conservation == |
| | [[Image:Consurf_key_small.gif|200px|right]] |
| | Check<jmol> |
| | <jmolCheckbox> |
| | <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/et/1et9_consurf.spt"</scriptWhenChecked> |
| | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> |
| | <text>to colour the structure by Evolutionary Conservation</text> |
| | </jmolCheckbox> |
| | </jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1et9 ConSurf]. |
| | <div style="clear:both"></div> |
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| '''CRYSTAL STRUCTURE OF THE SUPERANTIGEN SPE-H FROM STREPTOCOCCUS PYOGENES'''
| | ==See Also== |
| | | *[[Exotoxin 3D structures|Exotoxin 3D structures]] |
| | | __TOC__ |
| ==Overview== | | </StructureSection> |
| Bacterial superantigens (SAgs) are a structurally related group of protein toxins secreted by Staphylococcus aureus and Streptococcus pyogenes. They are implicated in a range of human pathologies associated with bacterial infection whose symptoms result from SAg-mediated stimulation of a large number (2-20%) of T-cells. At the molecular level, bacterial SAgs bind to major histocompatability class II (MHC-II) molecules and disrupt the normal interaction between MHC-II and T-cell receptors (TCRs). We have determined high-resolution crystal structures of two newly identified streptococcal superantigens, SPE-H and SMEZ-2. Both structures conform to the generic bacterial superantigen folding pattern, comprising an OB-fold N-terminal domain and a beta-grasp C-terminal domain. SPE-H and SMEZ-2 also display very similar zinc-binding sites on the outer concave surfaces of their C-terminal domains. Structural comparisons with other SAgs identify two structural sub-families. Sub-families are related by conserved core residues and demarcated by variable binding surfaces for MHC-II and TCR. SMEZ-2 is most closely related to the streptococcal SAg SPE-C, and together they constitute one structural sub-family. In contrast, SPE-H appears to be a hybrid whose N-terminal domain is most closely related to the SEB sub-family and whose C-terminal domain is most closely related to the SPE-C/SMEZ-2 sub-family. MHC-II binding for both SPE-H and SMEZ-2 is mediated by the zinc ion at their C-terminal face, whereas the generic N-terminal domain MHC-II binding site found on many SAgs appears not to be present. Structural comparisons provide evidence for variations in TCR binding between SPE-H, SMEZ-2 and other members of the SAg family; the extreme potency of SMEZ-2 (active at 10(-15) g ml-1 levels) is likely to be related to its TCR binding properties. The smez gene shows allelic variation that maps onto a considerable proportion of the protein surface. This allelic variation, coupled with the varied binding modes of SAgs to MHC-II and TCR, highlights the pressure on SAgs to avoid host immune defences.
| | [[Category: Large Structures]] |
| | |
| ==About this Structure==
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| 1ET9 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Streptococcus_pyogenes Streptococcus pyogenes]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1ET9 OCA].
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| ==Reference==
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| Conservation and variation in superantigen structure and activity highlighted by the three-dimensional structures of two new superantigens from Streptococcus pyogenes., Arcus VL, Proft T, Sigrell JA, Baker HM, Fraser JD, Baker EN, J Mol Biol. 2000 May 26;299(1):157-68. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/10860729 10860729]
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| [[Category: Single protein]] | |
| [[Category: Streptococcus pyogenes]] | | [[Category: Streptococcus pyogenes]] |
| [[Category: Arcus, V L.]] | | [[Category: Arcus VL]] |
| [[Category: Baker, E N.]] | | [[Category: Baker EN]] |
| [[Category: Baker, H M.]] | | [[Category: Baker HM]] |
| [[Category: Fraser, J D.]] | | [[Category: Fraser JD]] |
| [[Category: Proft, T.]] | | [[Category: Proft T]] |
| [[Category: Sigrell, J A.]] | | [[Category: Sigrell JA]] |
| [[Category: Beta grasp]]
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| [[Category: Ob fold]]
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| [[Category: Superantigen fold]]
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| ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 15:29:43 2008''
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