View source for 1b7d


==NEUROTOXIN (TS1) FROM BRAZILIAN SCORPION TITYUS SERRULATUS==
<StructureSection load='1b7d' size='340' side='right'caption='[[1b7d]], [[Resolution|resolution]] 1.73&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1b7d]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Tityus_serrulatus Tityus serrulatus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1B7D OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1B7D 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]] 1.73&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=PO4:PHOSPHATE+ION'>PO4</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=1b7d FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1b7d OCA], [https://pdbe.org/1b7d PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1b7d RCSB], [https://www.ebi.ac.uk/pdbsum/1b7d PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1b7d ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/SCX1_TITSE SCX1_TITSE] Beta toxins bind voltage-independently at site-4 of sodium channels (Nav) and shift the voltage of activation toward more negative potentials thereby affecting sodium channel activation and promoting spontaneous and repetitive firing. In addition, it stimulates the release of NO, IL-6 and TNF-alpha in J774.1 cells (PubMed:21549737). This toxin is active against both mammals and insects.<ref>PMID:21549737</ref> 
== 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/b7/1b7d_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.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=1b7d ConSurf].
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== Publication Abstract from PubMed ==
The crystal structure of neurotoxin Ts1, a major component of the venom of the Brazilian scorpion Tityus serrulatus, has been determined at 1.7 A resolution. It is the first X-ray structure of a highly toxic anti-mammalian beta-toxin. The folding of the polypeptide chain of Ts1 is similar to that of other scorpion toxins. A cysteine-stabilised alpha-helix/beta-sheet motif forms the core of the flattened molecule. All residues identified as functionally important by chemical modification and site-directed mutagenesis are located on one side of the molecule, which is therefore considered as the Na+channel recognition site. The distribution of charged and non-polar residues over this surface determines the specificity of the toxin-channel interaction. Comparison to other scorpion toxins shows that positively charged groups at positions 1 and 12 as well as a negative charge at position 2 are likely determinants of the specificity of beta-toxins. In contrast, the contribution of the conserved aromatic cluster to the interaction might be relatively small. Comparison of Ts1 to weak beta-toxins from Centruroides sculpturatus Ewing reveals that a number of basic amino acid residues located on the face of the molecule opposite to the binding surface may account for the high toxicity of Ts1.

Crystal structure of neurotoxin Ts1 from Tityus serrulatus provides insights into the specificity and toxicity of scorpion toxins.,Polikarpov I, Junior MS, Marangoni S, Toyama MH, Teplyakov A J Mol Biol. 1999 Jul 2;290(1):175-84. PMID:10388565<ref>PMID:10388565</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Tityus serrulatus]]
[[Category: Marangoni S]]
[[Category: Polikarpov I]]
[[Category: Sanches Jr MS]]
[[Category: Teplyakov A]]
[[Category: Toyama MH]]