View source for 4aq5


==Gating movement in acetylcholine receptor analysed by time-resolved electron cryo-microscopy (closed class)==
<SX load='4aq5' size='340' side='right' viewer='molstar' caption='[[4aq5]], [[Resolution|resolution]] 6.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4aq5]] is a 5 chain structure with sequence from [https://en.wikipedia.org/wiki/Torpedo_marmorata Torpedo marmorata]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4AQ5 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4AQ5 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 6.2&#8491;</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=4aq5 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4aq5 OCA], [https://pdbe.org/4aq5 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4aq5 RCSB], [https://www.ebi.ac.uk/pdbsum/4aq5 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4aq5 ProSAT]</span></td></tr>
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== Function ==
[https://www.uniprot.org/uniprot/ACHA_TORMA ACHA_TORMA] 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.
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== Publication Abstract from PubMed ==
The nicotinic acetylcholine (ACh) receptor converts transiently to an open-channel form when activated by ACh released into the synaptic cleft. We describe here the conformational change underlying this event, determined by electron microscopy of ACh-sprayed and freeze-trapped postsynaptic membranes. ACh binding to the alpha subunits triggers a concerted rearrangement in the ligand-binding domain, involving an ~1-A outward displacement of the extracellular portion of the beta subunit where it interacts with the juxtaposed ends of alpha-helices shaping the narrow membrane-spanning pore. The beta-subunit helices tilt outward to accommodate this displacement, destabilising the arrangement of pore-lining helices, which in the closed channel bend inward symmetrically to form a central hydrophobic gate. Straightening and tangential motion of the pore-lining helices effect channel opening by widening the pore asymmetrically and increasing its polarity in the region of the gate. The pore-lining helices of the alpha(gamma) and delta subunits, by flexing between alternative bent and straight conformations, undergo the greatest movements. This coupled allosteric transition shifts the structure from a tense (closed) state toward a more relaxed (open) state.

Gating movement of acetylcholine receptor caught by plunge-freezing.,Unwin N, Fujiyoshi Y J Mol Biol. 2012 Oct 5;422(5):617-34. Epub 2012 Jul 24. PMID:22841691<ref>PMID:22841691</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Acetyl choline receptor 3D structures|Acetyl choline receptor 3D structures]]
== References ==
<references/>
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[[Category: Large Structures]]
[[Category: Torpedo marmorata]]
[[Category: Fujiyoshi Y]]
[[Category: Unwin N]]