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1lqi

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(New page: 200px<br /><applet load="1lqi" size="450" color="white" frame="true" align="right" spinBox="true" caption="1lqi" /> '''INSECTICIDAL ALPHA SCORPION TOXIN ISOLATED F...)
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[[Image:1lqi.jpg|left|200px]]<br /><applet load="1lqi" size="450" color="white" frame="true" align="right" spinBox="true"
 
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caption="1lqi" />
 
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'''INSECTICIDAL ALPHA SCORPION TOXIN ISOLATED FROM THE VENOM OF SCORPION LEIURUS QUINQUESTRIATUS HEBRAEUS, NMR, 29 STRUCTURES'''<br />
 
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==Overview==
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==INSECTICIDAL ALPHA SCORPION TOXIN ISOLATED FROM THE VENOM OF SCORPION LEIURUS QUINQUESTRIATUS HEBRAEUS, NMR, 29 STRUCTURES==
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The solution structure of a recombinant active alpha-neurotoxin from, Leiurus quinquestriatus hebraeus, Lqh(alpha)IT, was determined by proton, two-dimensional nuclear magnetic resonance spectroscopy (2D NMR). This, toxin is the most insecticidal among scorpion alpha-neurotoxins and, therefore, serves as a model for clarifying the structural basis for their, biological activity and selective toxicity. A set of 29 structures was, generated without constraint violations exceeding 0.4 A. These structures, had root mean square deviations of 0.49 and 1.00 A with respect to the, average structure for backbone atoms and all heavy atoms, respectively., Similarly to other scorpion toxins, the structure of Lqh(alpha)IT consists, of an alpha-helix, a three-strand antiparallel beta-sheet, three type I, tight turns, a five-residue turn, and a hydrophobic patch that includes, tyrosine and tryptophan rings in a "herringbone" arrangement. Positive phi, angles were found for Ala50 and Asn11, suggesting their proximity to, functionally important regions of the molecule. The sample exhibited, conformational heterogeneity over a wide range of experimental conditions, and two conformations were observed for the majority of protein residues., The ratio between these conformations was temperature-dependent, and the, rate of their interconversions was estimated to be on the order of 1-5, s(-1) at 308 K. The conformation of the polypeptide backbone of, Lqh(alpha)IT is very similar to that of the most active antimammalian, scorpion alpha-toxin, AaHII, from Androctonus australis Hector (60% amino, acid sequence homology). Yet, several important differences were observed, at the 5-residue turn comprising residues Lys8-Cys12, the C-terminal, segment, and the mutual disposition of these two regions. 2D NMR studies, of the R64H mutant, which is 3 times more toxic than the unmodified, Lqh(alpha)IT, demonstrated the importance of the spatial orientation of, the last residue side chain for toxicity of Lqh(alpha)IT.
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<StructureSection load='1lqi' size='340' side='right'caption='[[1lqi]]' scene=''>
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== Structural highlights ==
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<table><tr><td colspan='2'>[[1lqi]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Leiurus_quinquestriatus_hebraeus Leiurus quinquestriatus hebraeus]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1LQI OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1LQI FirstGlance]. <br>
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</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR</td></tr>
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<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1lqi FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1lqi OCA], [https://pdbe.org/1lqi PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1lqi RCSB], [https://www.ebi.ac.uk/pdbsum/1lqi PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1lqi ProSAT]</span></td></tr>
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</table>
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== Function ==
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[https://www.uniprot.org/uniprot/SCXA_LEIHE SCXA_LEIHE] Alpha toxins bind voltage-independently at site-3 of sodium channels (Nav) and inhibit the inactivation of the activated channels, thereby blocking neuronal transmission. The dissociation is voltage-dependent. This toxin is active on insects. It is also highly toxic to crustaceans and has a measurable but low toxicity to mice.
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== Evolutionary Conservation ==
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[[Image:Consurf_key_small.gif|200px|right]]
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Check<jmol>
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<jmolCheckbox>
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<scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/lq/1lqi_consurf.spt"</scriptWhenChecked>
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<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
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<text>to colour the structure by Evolutionary Conservation</text>
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</jmolCheckbox>
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</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=1lqi ConSurf].
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<div style="clear:both"></div>
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==About this Structure==
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==See Also==
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1LQI is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Leiurus_quinquestriatus_hebraeus Leiurus quinquestriatus hebraeus]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1LQI OCA].
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*[[Hemolysin 3D structures|Hemolysin 3D structures]]
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*[[Potassium channel toxin 3D structures|Potassium channel toxin 3D structures]]
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==Reference==
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__TOC__
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Solution structures of a highly insecticidal recombinant scorpion alpha-toxin and a mutant with increased activity., Tugarinov V, Kustanovich I, Zilberberg N, Gurevitz M, Anglister J, Biochemistry. 1997 Mar 4;36(9):2414-24. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=9054546 9054546]
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</StructureSection>
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[[Category: Large Structures]]
[[Category: Leiurus quinquestriatus hebraeus]]
[[Category: Leiurus quinquestriatus hebraeus]]
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[[Category: Single protein]]
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[[Category: Anglister J]]
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[[Category: Anglister, J.]]
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[[Category: Gurevitz M]]
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[[Category: Gurevitz, M.]]
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[[Category: Kustanovich I]]
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[[Category: Kustanovich, I.]]
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[[Category: Tugarinov V]]
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[[Category: Tugarinov, V.]]
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[[Category: Zilberberg N]]
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[[Category: Zilberberg, N.]]
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[[Category: neurotoxin]]
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[[Category: signal]]
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[[Category: sodium channel inhibitor]]
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''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 20:46:58 2007''
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Current revision

INSECTICIDAL ALPHA SCORPION TOXIN ISOLATED FROM THE VENOM OF SCORPION LEIURUS QUINQUESTRIATUS HEBRAEUS, NMR, 29 STRUCTURES

PDB ID 1lqi

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