2byq: Difference between revisions

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-[[Image:2byq.gif|left|200px]]<br /><applet load="2byq" size="450" color="white" frame="true" align="right" spinBox="true"
-caption="2byq, resolution 3.40&Aring;" />
-'''CRYSTAL STRUCTURE OF APLYSIA CALIFORNICA ACHBP IN COMPLEX WITH EPIBATIDINE'''<br />
-==Overview==
+==Crystal structure of Aplysia californica AChBP in complex with epibatidine==
-The crystal structure of the snake long alpha-neurotoxin, alpha-cobratoxin, bound to the pentameric acetylcholine-binding protein, (AChBP) from Lymnaea stagnalis, was solved from good quality density maps, despite a 4.2 A overall resolution. The structure unambiguously reveals, the positions and orientations of all five three-fingered toxin molecules, inserted at the AChBP subunit interfaces and the conformational changes, associated with toxin binding. AChBP loops C and F that border the, ligand-binding pocket move markedly from their original positions to wrap, around the tips of the toxin first and second fingers and part of its, C-terminus, while rearrangements also occur in the toxin fingers. At the, interface of the complex, major interactions involve aromatic and, aliphatic side chains within the AChBP binding pocket and, at the buried, tip of the toxin second finger, conserved Phe and Arg residues that, partially mimic a bound agonist molecule. Hence this structure, in, revealing a distinctive and unpredicted conformation of the toxin-bound, AChBP molecule, provides a lead template resembling a resting state, conformation of the nicotinic receptor and for understanding selectivity, of curaremimetic alpha-neurotoxins for the various receptor species.
+<StructureSection load='2byq' size='340' side='right'caption='[[2byq]], [[Resolution|resolution]] 3.40&Aring;' scene=''>
+== Structural highlights ==
+<table><tr><td colspan='2'>[[2byq]] is a 5 chain structure with sequence from [https://en.wikipedia.org/wiki/Aplysia_californica Aplysia californica]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2BYQ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2BYQ 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]] 3.4&#8491;</td></tr>
+<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=EPJ:EPIBATIDINE'>EPJ</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=2byq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2byq OCA], [https://pdbe.org/2byq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2byq RCSB], [https://www.ebi.ac.uk/pdbsum/2byq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2byq ProSAT]</span></td></tr>
+</table>
+== Function ==
+[https://www.uniprot.org/uniprot/Q8WSF8_APLCA Q8WSF8_APLCA]
+== 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/by/2byq_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=2byq ConSurf].
+<div style="clear:both"></div>
+<div style="background-color:#fffaf0;">
+== Publication Abstract from PubMed ==
+Upon ligand binding at the subunit interfaces, the extracellular domain of the nicotinic acetylcholine receptor undergoes conformational changes, and agonist binding allosterically triggers opening of the ion channel. The soluble acetylcholine-binding protein (AChBP) from snail has been shown to be a structural and functional surrogate of the ligand-binding domain (LBD) of the receptor. Yet, individual AChBP species display disparate affinities for nicotinic ligands. The crystal structure of AChBP from Aplysia californica in the apo form reveals a more open loop C and distinctive positions for other surface loops, compared with previous structures. Analysis of Aplysia AChBP complexes with nicotinic ligands shows that loop C, which does not significantly change conformation upon binding of the antagonist, methyllycaconitine, further opens to accommodate the peptidic antagonist, alpha-conotoxin ImI, but wraps around the agonists lobeline and epibatidine. The structures also reveal extended and nonoverlapping interaction surfaces for the two antagonists, outside the binding loci for agonists. This comprehensive set of structures reflects a dynamic template for delineating further conformational changes of the LBD of the nicotinic receptor.
-==About this Structure==
+Structures of Aplysia AChBP complexes with nicotinic agonists and antagonists reveal distinctive binding interfaces and conformations.,Hansen SB, Sulzenbacher G, Huxford T, Marchot P, Taylor P, Bourne Y EMBO J. 2005 Oct 19;24(20):3635-46. Epub 2005 Sep 29. PMID:16193063<ref>PMID:16193063</ref>
-BYQ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Aplysia_californica Aplysia californica] with EPJ as [http://en.wikipedia.org/wiki/ligand ligand]. Known structural/functional Site: <scene name='pdbsite=AC1:Epj Binding Site For Chain E'>AC1</scene>. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2BYQ OCA].
-==Reference==
+From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
-Crystal structure of a Cbtx-AChBP complex reveals essential interactions between snake alpha-neurotoxins and nicotinic receptors., Bourne Y, Talley TT, Hansen SB, Taylor P, Marchot P, EMBO J. 2005 Apr 20;24(8):1512-22. Epub 2005 Mar 24. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=15791209 15791209]
+</div>
+<div class="pdbe-citations 2byq" style="background-color:#fffaf0;"></div>
+==See Also==
+*[[Acetylcholine binding protein 3D structures|Acetylcholine binding protein 3D structures]]
+== References ==
+<references/>
+__TOC__
+</StructureSection>
 [[Category: Aplysia californica]]
-[[Category: Single protein]]
+[[Category: Large Structures]]
-[[Category: Bourne, Y.]]
+[[Category: Bourne Y]]
-[[Category: Hansen, S.B.]]
+[[Category: Hansen SB]]
-[[Category: Huxford, T.]]
+[[Category: Huxford T]]
-[[Category: Marchot, P.]]
+[[Category: Marchot P]]
-[[Category: Sulzenbacher, G.]]
+[[Category: Sulzenbacher G]]
-[[Category: Taylor, P.]]
+[[Category: Taylor P]]
-[[Category: EPJ]]
-[[Category: acetylcholine binding protein]]
-[[Category: agonist]]
-[[Category: conformational flexibility]]
-[[Category: nicotinic acetylcholine]]
-[[Category: receptor]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Dec 18 19:03:29 2007''