View source for 5ain


==Varenicline Interactions at the 5HT3 Receptor Ligand Binding Site are Revealed by 5HTBP==
<StructureSection load='5ain' size='340' side='right'caption='[[5ain]], [[Resolution|resolution]] 2.30&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5ain]] 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=5AIN OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5AIN 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]] 2.3&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=QMR:VARENICLINE'>QMR</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=5ain FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5ain OCA], [https://pdbe.org/5ain PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5ain RCSB], [https://www.ebi.ac.uk/pdbsum/5ain PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5ain ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q8WSF8_APLCA Q8WSF8_APLCA] 
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== Publication Abstract from PubMed ==
Cys-loop receptors are the site of action of many therapeutic drugs. One of these is the smoking cessation agent varenicline, which has its major therapeutic effects at nicotinic acetylcholine (nACh) receptors but also acts at 5-HT3 receptors. Here, we report the X-ray crystal structure of the 5-HT binding protein (5-HTBP) in complex with varenicline, and test the predicted interactions by probing the potency of varenicline in a range of mutant 5-HT3 receptors expressed in HEK293 cells and Xenopus oocytes. The structure reveals a range of interactions between varenicline and 5-HTBP. We identified residues within 5 A of varenicline and substituted the equivalent residues in the 5-HT3 receptor with Ala or a residue with similar chemical properties. Functional characterization of these mutant 5-HT3 receptors, using a fluorescent membrane potential dye in HEK cells and voltage clamp in oocytes, supports interactions between varenicline and the receptor that are similar to those in 5-HTBP. The structure also revealed C-loop closure that was less than in the 5-HT-bound 5-HTBP, and hydrogen bonding between varenicline and the complementary face of the binding pocket via a water molecule, which are characteristics consistent with partial agonist behavior of varenicline in the 5-HT3 receptor. Together, these data reveal detailed insights into the molecular interaction of varenicline in the 5-HT3 receptor.

Varenicline Interactions at the 5-HT3 Receptor Ligand Binding Site are Revealed by 5-HTBP.,Price KL, Lillestol RK, Ulens C, Lummis SC ACS Chem Neurosci. 2015 Jul 15;6(7):1151-7. doi: 10.1021/cn500369h. Epub 2015 Feb, 19. PMID:25648658<ref>PMID:25648658</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 5ain" style="background-color:#fffaf0;"></div>

==See Also==
*[[Acetylcholine binding protein 3D structures|Acetylcholine binding protein 3D structures]]
== References ==
<references/>
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</StructureSection>
[[Category: Aplysia californica]]
[[Category: Large Structures]]
[[Category: Lillestol R]]
[[Category: Lummis SC]]
[[Category: Price KL]]
[[Category: Ulens C]]