View source for 3c79


==Crystal structure of Aplysia californica AChBP in complex with the neonicotinoid imidacloprid==
<StructureSection load='3c79' size='340' side='right'caption='[[3c79]], [[Resolution|resolution]] 2.48&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3c79]] 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=3C79 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3C79 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]] 2.48&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=IM4:(2E)-1-[(6-CHLOROPYRIDIN-3-YL)METHYL]-N-NITROIMIDAZOLIDIN-2-IMINE'>IM4</scene>, <scene name='pdbligand=IPA:ISOPROPYL+ALCOHOL'>IPA</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=3c79 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3c79 OCA], [https://pdbe.org/3c79 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3c79 RCSB], [https://www.ebi.ac.uk/pdbsum/3c79 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3c79 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/c7/3c79_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=3c79 ConSurf].
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== Publication Abstract from PubMed ==
Acetylcholine-binding proteins (AChBPs) from mollusks are suitable structural and functional surrogates of the nicotinic acetylcholine receptors when combined with transmembrane spans of the nicotinic receptor. These proteins assemble as a pentamer with identical ACh binding sites at the subunit interfaces and show ligand specificities resembling those of the nicotinic receptor for agonists and antagonists. A subset of ligands, termed the neonicotinoids, exhibit specificity for insect nicotinic receptors and selective toxicity as insecticides. AChBPs are of neither mammalian nor insect origin and exhibit a distinctive pattern of selectivity for the neonicotinoid ligands. We define here the binding orientation and determinants of differential molecular recognition for the neonicotinoids and classical nicotinoids by estimates of kinetic and equilibrium binding parameters and crystallographic analysis. Neonicotinoid complex formation is rapid and accompanied by quenching of the AChBP tryptophan fluorescence. Comparisons of the neonicotinoids imidacloprid and thiacloprid in the binding site from Aplysia californica AChBP at 2.48 and 1.94 A in resolution reveal a single conformation of the bound ligands with four of the five sites occupied in the pentameric crystal structure. The neonicotinoid electronegative pharmacophore is nestled in an inverted direction compared with the nicotinoid cationic functionality at the subunit interfacial binding pocket. Characteristic of several agonists, loop C largely envelops the ligand, positioning aromatic side chains to interact optimally with conjugated and hydrophobic regions of the neonicotinoid. This template defines the association of interacting amino acids and their energetic contributions to the distinctive interactions of neonicotinoids.

Atomic interactions of neonicotinoid agonists with AChBP: molecular recognition of the distinctive electronegative pharmacophore.,Talley TT, Harel M, Hibbs RE, Radic Z, Tomizawa M, Casida JE, Taylor P Proc Natl Acad Sci U S A. 2008 May 27;105(21):7606-11. Epub 2008 May 13. PMID:18477694<ref>PMID:18477694</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 3c79" 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: Large Structures]]
[[Category: Casida JE]]
[[Category: Harel M]]
[[Category: Hibbs RE]]
[[Category: Talley TT]]
[[Category: Taylor PW]]
[[Category: Tomizawa M]]