View source for 7smq


==Cryo-EM structure of Torpedo acetylcholine receptor in apo form with added cholesterol==
<StructureSection load='7smq' size='340' side='right'caption='[[7smq]], [[Resolution|resolution]] 2.74&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[7smq]] is a 5 chain structure with sequence from [https://en.wikipedia.org/wiki/Tetronarce_californica Tetronarce californica]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7SMQ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7SMQ 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]] 2.74&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BMA:BETA-D-MANNOSE'>BMA</scene>, <scene name='pdbligand=CLR:CHOLESTEROL'>CLR</scene>, <scene name='pdbligand=DD9:NONANE'>DD9</scene>, <scene name='pdbligand=MAN:ALPHA-D-MANNOSE'>MAN</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=POV:(2S)-3-(HEXADECANOYLOXY)-2-[(9Z)-OCTADEC-9-ENOYLOXY]PROPYL+2-(TRIMETHYLAMMONIO)ETHYL+PHOSPHATE'>POV</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=7smq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7smq OCA], [https://pdbe.org/7smq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7smq RCSB], [https://www.ebi.ac.uk/pdbsum/7smq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7smq ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/ACHA_TETCF ACHA_TETCF] 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 ==
Binding of the neurotransmitter acetylcholine to its receptors on muscle fibers depolarizes the membrane and thereby triggers muscle contraction. We sought to understand at the level of three-dimensional structure how agonists and antagonists alter nicotinic acetylcholine receptor conformation. We used the muscle-type receptor from the Torpedo ray to first define the structure of the receptor in a resting, activatable state. We then determined the receptor structure bound to the agonist carbachol, which stabilizes an asymmetric, closed channel desensitized state. We find conformational changes in a peripheral membrane helix are tied to recovery from desensitization. To probe mechanisms of antagonism, we obtained receptor structures with the active component of curare, a poison arrow toxin and precursor to modern muscle relaxants. d-Tubocurarine stabilizes the receptor in a desensitized-like state in the presence and absence of agonist. These findings define the transitions between resting and desensitized states and reveal divergent means by which antagonists block channel activity of the muscle-type nicotinic receptor.

Structural mechanism of muscle nicotinic receptor desensitization and block by curare.,Rahman MM, Basta T, Teng J, Lee M, Worrell BT, Stowell MHB, Hibbs RE Nat Struct Mol Biol. 2022 Apr;29(4):386-394. doi: 10.1038/s41594-022-00737-3. , Epub 2022 Mar 17. PMID:35301478<ref>PMID:35301478</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 7smq" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Tetronarce californica]]
[[Category: Basta T]]
[[Category: Hibbs RE]]
[[Category: Lee M]]
[[Category: Rahman MM]]
[[Category: Stowell MHB]]
[[Category: Teng J]]
[[Category: Worrell BT]]