View source for 1kc4


==NMR Structural Analysis of the Complex Formed Between alpha-Bungarotoxin and the Principal alpha-Neurotoxin Binding Sequence on the alpha7 Subunit of a Neuronal Nicotinic Acetylcholine Receptor==
<StructureSection load='1kc4' size='340' side='right'caption='[[1kc4]], [[NMR_Ensembles_of_Models | 10 NMR models]]' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1kc4]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Bunmu Bunmu] and [https://en.wikipedia.org/wiki/Chick Chick]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1KC4 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1KC4 FirstGlance]. <br>
</td></tr><tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=HSL:HOMOSERINE+LACTONE'>HSL</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[1abt|1abt]], [[1idh|1idh]], [[2abx|2abx]], [[1i9b|1i9b]], [[1haj|1haj]], [[1hc9|1hc9]], [[1bxp|1bxp]], [[1jbd|1jbd]], [[1ikc|1ikc]], [[1kfh|1kfh]], [[1kl8|1kl8]]</div></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=1kc4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1kc4 OCA], [https://pdbe.org/1kc4 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1kc4 RCSB], [https://www.ebi.ac.uk/pdbsum/1kc4 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1kc4 ProSAT]</span></td></tr>
</table>
== Function ==
[[https://www.uniprot.org/uniprot/NXL1A_BUNMU NXL1A_BUNMU]] Binds with high affinity to muscular and neuronal (alpha-7, alpha-8, and alpha-9) nicotinic acetylcholine receptors. Produces peripheral paralysis by blocking neuromuscular transmission at the postsynaptic site. Blocks the extracellular increase of dopamine evoked by nicotine only at the higher dose (4.2 uM).<ref>PMID:9305882</ref> <ref>PMID:9840221</ref>  [[https://www.uniprot.org/uniprot/ACHA7_CHICK ACHA7_CHICK]] After binding acetylcholine, the AChR responds by an extensive change in conformation that affects all subunits and leads to opening of an ion-conducting channel across the plasma membrane. 
== 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/kc/1kc4_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=1kc4 ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
We report a new, higher resolution NMR structure of alpha-bungarotoxin that defines the structure-determining disulfide core and beta-sheet regions. We further report the NMR structure of the stoichiometric complex formed between alpha-bungarotoxin and a recombinantly expressed 19-mer peptide ((178)IPGKRTESFYECCKEPYPD(196)) derived from the alpha7 subunit of the chick neuronal nicotinic acetylcholine receptor. A comparison of these two structures reveals binding-induced stabilization of the flexible tip of finger II in alpha-bungarotoxin. The conformational rearrangements in the toxin create an extensive binding surface involving both sides of the alpha7 19-mer hairpin-like structure. At the contact zone, Ala(7), Ser(9), and Ile(11) in finger I and Arg(36), Lys(38), Val(39), and Val(40) in finger II of alpha-bungarotoxin interface with Phe(186), Tyr(187), Glu(188), and Tyr(194) in the alpha7 19-mer underscoring the importance of receptor aromatic residues as critical neurotoxin-binding determinants. Superimposing the structure of the complex onto that of the acetylcholine-binding protein (1I9B), a soluble homologue of the extracellular domain of the alpha7 receptor, places alpha-bungarotoxin at the peripheral surface of the inter-subunit interface occluding the agonist-binding site. The disulfide-rich core of alpha-bungarotoxin is suggested to be tilted in the direction of the membrane surface with finger II extending into the proposed ligand-binding cavity.

NMR structural analysis of alpha-bungarotoxin and its complex with the principal alpha-neurotoxin-binding sequence on the alpha 7 subunit of a neuronal nicotinic acetylcholine receptor.,Moise L, Piserchio A, Basus VJ, Hawrot E J Biol Chem. 2002 Apr 5;277(14):12406-17. Epub 2002 Jan 14. PMID:11790782<ref>PMID:11790782</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 1kc4" style="background-color:#fffaf0;"></div>

==See Also==
*[[Bungarotoxin 3D structures|Bungarotoxin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Bunmu]]
[[Category: Chick]]
[[Category: Large Structures]]
[[Category: Basus, V J]]
[[Category: Hawrot, E]]
[[Category: Moise, L]]
[[Category: Piserchio, A]]
[[Category: Alpha-bungarotoxin]]
[[Category: Alpha-neurotoxin]]
[[Category: Ligand-gated ion channel]]
[[Category: Nicotinic acetylcholine receptor alpha 7 subunit]]
[[Category: Protein-peptide complex]]
[[Category: Protein-protein interaction]]
[[Category: Toxin]]