View source for 2x00


==CRYSTAL STRUCTURE OF A-ACHBP IN COMPLEX WITH GYMNODIMINE A==
<StructureSection load='2x00' size='340' side='right'caption='[[2x00]], [[Resolution|resolution]] 2.40&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2x00]] is a 5 chain structure with sequence from [http://en.wikipedia.org/wiki/Aplca Aplca]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2X00 OCA]. For a <b>guided tour on the structure components</b> use [http://proteopedia.org/fgij/fg.htm?mol=2X00 FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GYN:GYMNODIMINE+A'>GYN</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[2wn9|2wn9]], [[2w8f|2w8f]], [[2byp|2byp]], [[2c9t|2c9t]], [[2byq|2byq]], [[2w8g|2w8g]], [[2uz6|2uz6]], [[2wnl|2wnl]], [[2br7|2br7]], [[2br8|2br8]], [[2byr|2byr]], [[2byn|2byn]], [[2bys|2bys]], [[2wnj|2wnj]], [[2w8e|2w8e]], [[2wzy|2wzy]], [[2wnc|2wnc]]</td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://proteopedia.org/fgij/fg.htm?mol=2x00 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2x00 OCA], [http://pdbe.org/2x00 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2x00 RCSB], [http://www.ebi.ac.uk/pdbsum/2x00 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=2x00 ProSAT]</span></td></tr>
</table>
== 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/x0/2x00_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=2x00 ConSurf].
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== Publication Abstract from PubMed ==
Spirolide and gymnodimine macrocyclic imine phycotoxins belong to an emerging class of chemical agents associated with marine algal blooms and shellfish toxicity. Analysis of 13-desmethyl spirolide C and gymnodimine A by binding and voltage-clamp recordings on muscle-type alpha1(2)betagammadelta and neuronal alpha3beta2 and alpha4beta2 nicotinic acetylcholine receptors reveals subnanomolar affinities, potent antagonism, and limited subtype selectivity. Their binding to acetylcholine-binding proteins (AChBP), as soluble receptor surrogates, exhibits picomolar affinities governed by diffusion-limited association and slow dissociation, accounting for apparent irreversibility. Crystal structures of the phycotoxins bound to Aplysia-AChBP ( approximately 2.4A) show toxins neatly imbedded within the nest of ar-omatic side chains contributed by loops C and F on opposing faces of the subunit interface, and which in physiological conditions accommodates acetylcholine. The structures also point to three major features: (i) the sequence-conserved loop C envelops the bound toxins to maximize surface complementarity; (ii) hydrogen bonding of the protonated imine nitrogen in the toxins with the carbonyl oxygen of loop C Trp147 tethers the toxin core centered within the pocket; and (iii) the spirolide bis-spiroacetal or gymnodimine tetrahydrofuran and their common cyclohexene-butyrolactone further anchor the toxins in apical and membrane directions, along the subunit interface. In contrast, the se-quence-variable loop F only sparingly contributes contact points to preserve the broad receptor subtype recognition unique to phycotoxins compared with other nicotinic antagonists. These data offer unique means for detecting spiroimine toxins in shellfish and identify distinctive ligands, functional determinants and binding regions for the design of new drugs able to target several receptor subtypes with high affinity.

Structural determinants in phycotoxins and AChBP conferring high affinity binding and nicotinic AChR antagonism.,Bourne Y, Radic Z, Araoz R, Talley TT, Benoit E, Servent D, Taylor P, Molgo J, Marchot P Proc Natl Acad Sci U S A. 2010 Mar 11. PMID:20224036<ref>PMID:20224036</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 2x00" style="background-color:#fffaf0;"></div>

==See Also==
*[[Acetylcholine binding protein 3D structures|Acetylcholine binding protein 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Aplca]]
[[Category: Large Structures]]
[[Category: Araoz, R]]
[[Category: Benoit, E]]
[[Category: Bourne, Y]]
[[Category: Marchot, P]]
[[Category: Molgo, J]]
[[Category: Radic, Z]]
[[Category: Servent, D]]
[[Category: Talley, T T]]
[[Category: Taylor, P]]
[[Category: Acetylcholine binding protein]]
[[Category: Phycotoxin]]
[[Category: Receptor]]
[[Category: Toxin]]