View source for 1txa


==SOLUTION NMR STRUCTURE OF TOXIN B, A LONG NEUROTOXIN FROM THE VENOM OF THE KING COBRA, MINIMIZED AVERAGE STRUCTURE==
<StructureSection load='1txa' size='340' side='right'caption='[[1txa]]' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1txa]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Ophiophagus_hannah Ophiophagus hannah]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TXA OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1TXA 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=1txa FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1txa OCA], [https://pdbe.org/1txa PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1txa RCSB], [https://www.ebi.ac.uk/pdbsum/1txa PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1txa ProSAT]</span></td></tr>
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== Function ==
[https://www.uniprot.org/uniprot/3L22_OPHHA 3L22_OPHHA] Binds with high affinity to muscular (alpha-1/CHRNA1) and neuronal (alpha-7/CHRNA7) nicotinic acetylcholine receptor (nAChR) and inhibits acetylcholine from binding to the receptor, thereby impairing neuromuscular and neuronal transmission.[UniProtKB:P60615]
== 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/tx/1txa_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=1txa ConSurf].
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== Publication Abstract from PubMed ==
The solution structure of toxin b, a long neurotoxin (73 amino acids and 5 disulfides) from the venom of Ophiophagus hannah (king cobra), has been determined using 1H NMR and dynamical simulated annealing techniques. The structures were calculated using 485 distance constraints and 52 dihedral angle restraints. The 21 structures that were obtained satisfy the experimental restraints and possess good nonbonded contacts. Analysis of the converged structures revealed that the protein consists of a core region from which three finger-like loops extend outwards. The regular secondary structure in toxin b includes a double and a triple stranded antiparallel beta sheet. Comparison with the solution structures of other long neurotoxins reveals that although the structure of toxin b is similar to those of previously reported long neurotoxins, clear local structural differences are observed in regions proposed to be involved in binding to the acetylcholine receptor. A positively charged cluster is found in the C-terminal tail, in Loop III, and in the tip of Loop II. This cationic cluster could be crucial for the binding of the long neurotoxins to the acetylcholine receptor.

Solution structure of toxin b, a long neurotoxin from the venom of the king cobra (Ophiophagus hannah).,Peng SS, Kumar TK, Jayaraman G, Chang CC, Yu C J Biol Chem. 1997 Mar 21;272(12):7817-23. PMID:9065446<ref>PMID:9065446</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: Ophiophagus hannah]]
[[Category: Chang C-C]]
[[Category: Jayaraman G]]
[[Category: Kumar TKS]]
[[Category: Peng S-S]]
[[Category: Yu C]]