View source for 2b3c


==SOLUTION STRUCTURE OF A BETA-NEUROTOXIN FROM THE NEW WORLD SCORPION CENTRUROIDES SCULPTURATUS EWING==
<StructureSection load='2b3c' size='340' side='right'caption='[[2b3c]]' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2b3c]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Centruroides_sculpturatus Centruroides sculpturatus]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2B3C OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2B3C FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR, 1 model</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=2b3c FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2b3c OCA], [https://pdbe.org/2b3c PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2b3c RCSB], [https://www.ebi.ac.uk/pdbsum/2b3c PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2b3c ProSAT]</span></td></tr>
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== Function ==
[https://www.uniprot.org/uniprot/SCXI_CENSC SCXI_CENSC] 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. Affects channels from chicken and frog.
== 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/b3/2b3c_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=2b3c ConSurf].
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== Publication Abstract from PubMed ==
We report the detailed solution structure of the 7.2 kDa protein CsE-I, a beta-neurotoxin from the New World scorpion Centruroides sculpturatus Ewing. This toxin binds to sodium channels, but unlike the alpha-neurotoxins, shifts the voltage of activation toward more negative potentials causing the membrane to fire spontaneously. Sequence-specific proton NMR assignments were made using 600 MHz 2D-NMR data. Distance geometry and dynamical simulated annealing refinements were performed using experimental distance and torsion angle constraints from NOESY and pH-COSY data. A family of 40 structures without constraint violations was generated, and an energy-minimized average structure was computed. The backbone conformation of the CsE-I toxin shows similar secondary structural features as the prototypical alpha-neurotoxin, CsE-v3, and is characterized by a short 2(1/2)-turn alpha-helix and a 3-strand antiparallel beta-sheet, both held together by disulfide bridges. The RMSD for the backbone atoms between CsE-I and CsE-v3 is 1.48 A. Despite this similarity in the overall backbone folding, the these two proteins show some important differences in the primary structure (sequence) and electrostatic potential surfaces. Our studies provide a basis for unravelling the role of these differences in relation to the known differences in the receptor sites on the voltage sensitive sodium channel for the alpha- and beta-neurotoxins.

Solution structure of a beta-neurotoxin from the New World scorpion Centruroides sculpturatus Ewing.,Jablonsky MJ, Jackson PL, Trent JO, Watt DD, Krishna NR Biochem Biophys Res Commun. 1999 Jan 19;254(2):406-12. PMID:9918851<ref>PMID:9918851</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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== References ==
<references/>
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</StructureSection>
[[Category: Centruroides sculpturatus]]
[[Category: Large Structures]]
[[Category: Jablonsky MJ]]
[[Category: Jackson PL]]
[[Category: Krishna NR]]
[[Category: Trent JO]]
[[Category: Watt DD]]