1ewc: Difference between revisions

New page: left|200px<br /><applet load="1ewc" size="450" color="white" frame="true" align="right" spinBox="true" caption="1ewc, resolution 1.95Å" /> '''CRYSTAL STRUCTURE OF...
 
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[[Image:1ewc.gif|left|200px]]<br /><applet load="1ewc" size="450" color="white" frame="true" align="right" spinBox="true"
caption="1ewc, resolution 1.95&Aring;" />
'''CRYSTAL STRUCTURE OF ZN2+ LOADED STAPHYLOCOCCAL ENTEROTOXIN H'''<br />


==Overview==
==CRYSTAL STRUCTURE OF ZN2+ LOADED STAPHYLOCOCCAL ENTEROTOXIN H==
The X-ray structure of the superantigen staphylococcal enterotoxin H (SEH), has been determined at 1.69 A resolution. In this paper we present two, structures of zinc-free SEH (apoSEH) and one zinc-loaded form of SEH, (ZnSEH). SEH exhibits the conventional superantigen (SAg) fold with two, characteristic domains. In ZnSEH one zinc ion per SEH molecule is bound to, the C-terminal beta-sheet in the region implicated for major, histocompatibility complex class II (MHC class II) binding in SEA, SED and, SEE. Surprisingly, the zinc ion has only two ligating amino acid residues, His206 and Asp208. The other ligands to the zinc ion are two water, molecules. An extensive packing interaction between two symmetry-related, molecules in the crystal, 834 A(2)/molecule, forms a cavity that buries, the zinc ions of the molecules. This dimer-like interaction is found in, two crystal forms. Nevertheless, zinc-dependent dimerisation is not, observed in solution, as seen in the case of SED. A unique feature of SEH, as compared to other staphylococcal enterotoxins is a large negatively, charged surface close to the Zn(2+) site. The interaction of SEH with MHC, class II is the strongest known among the staphylococcal enterotoxins., However, SEH seems to lack a SEB-like MHC class II binding site, since the, side-chain properties of structurally equivalent amino acid residues in, SEH and those in SEB-binding MHC class II differ dramatically. There is, also a structural flexibility between the domains of SEH. The domains of, two apoSEH structures are related by a 5 degrees rotation leading to at, most 3 A difference in C(alpha) positions. Since the T-cell receptor, probably interacts with both domains, SEH by this rotation may modulate, its binding to different TcR Vbeta-chains.
<StructureSection load='1ewc' size='340' side='right'caption='[[1ewc]], [[Resolution|resolution]] 1.95&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1ewc]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Staphylococcus_aureus Staphylococcus aureus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1EWC OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1EWC FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.95&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ZN:ZINC+ION'>ZN</scene></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=1ewc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ewc OCA], [https://pdbe.org/1ewc PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1ewc RCSB], [https://www.ebi.ac.uk/pdbsum/1ewc PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1ewc ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/ETXH_STAAU ETXH_STAAU] Staphylococcal enterotoxins cause the intoxication staphylococcal food poisoning syndrome. The illness characterized by high fever, hypotension, diarrhea, shock, and in some cases death.
== 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/ew/1ewc_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=1ewc ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The X-ray structure of the superantigen staphylococcal enterotoxin H (SEH) has been determined at 1.69 A resolution. In this paper we present two structures of zinc-free SEH (apoSEH) and one zinc-loaded form of SEH (ZnSEH). SEH exhibits the conventional superantigen (SAg) fold with two characteristic domains. In ZnSEH one zinc ion per SEH molecule is bound to the C-terminal beta-sheet in the region implicated for major histocompatibility complex class II (MHC class II) binding in SEA, SED and SEE. Surprisingly, the zinc ion has only two ligating amino acid residues His206 and Asp208. The other ligands to the zinc ion are two water molecules. An extensive packing interaction between two symmetry-related molecules in the crystal, 834 A(2)/molecule, forms a cavity that buries the zinc ions of the molecules. This dimer-like interaction is found in two crystal forms. Nevertheless, zinc-dependent dimerisation is not observed in solution, as seen in the case of SED. A unique feature of SEH as compared to other staphylococcal enterotoxins is a large negatively charged surface close to the Zn(2+) site. The interaction of SEH with MHC class II is the strongest known among the staphylococcal enterotoxins. However, SEH seems to lack a SEB-like MHC class II binding site, since the side-chain properties of structurally equivalent amino acid residues in SEH and those in SEB-binding MHC class II differ dramatically. There is also a structural flexibility between the domains of SEH. The domains of two apoSEH structures are related by a 5 degrees rotation leading to at most 3 A difference in C(alpha) positions. Since the T-cell receptor probably interacts with both domains, SEH by this rotation may modulate its binding to different TcR Vbeta-chains.


==About this Structure==
The crystal structure of staphylococcal enterotoxin H: implications for binding properties to MHC class II and TcR molecules.,Hakansson M, Petersson K, Nilsson H, Forsberg G, Bjork P, Antonsson P, Svensson LA J Mol Biol. 2000 Sep 22;302(3):527-37. PMID:10986116<ref>PMID:10986116</ref>
1EWC is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Staphylococcus_aureus Staphylococcus aureus] with ZN as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1EWC OCA].


==Reference==
From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
The crystal structure of staphylococcal enterotoxin H: implications for binding properties to MHC class II and TcR molecules., Hakansson M, Petersson K, Nilsson H, Forsberg G, Bjork P, Antonsson P, Svensson LA, J Mol Biol. 2000 Sep 22;302(3):527-37. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=10986116 10986116]
</div>
[[Category: Single protein]]
<div class="pdbe-citations 1ewc" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Staphylococcus aureus]]
[[Category: Staphylococcus aureus]]
[[Category: Antonsson, P.]]
[[Category: Antonsson P]]
[[Category: Bjork, P.]]
[[Category: Bjork P]]
[[Category: Forsberg, G.]]
[[Category: Forsberg G]]
[[Category: Hakansson, M.]]
[[Category: Hakansson M]]
[[Category: Nilsson, H.]]
[[Category: Nilsson H]]
[[Category: Petersson, K.]]
[[Category: Petersson K]]
[[Category: Svensson, A.]]
[[Category: Svensson A]]
[[Category: ZN]]
[[Category: beta-barrel]]
[[Category: beta-grasp]]
 
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