2bg9
From Proteopedia
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| - | [[Image:2bg9.gif|left|200px]]<br /><applet load="2bg9" size="350" color="white" frame="true" align="right" spinBox="true" | ||
| - | caption="2bg9, resolution 4.00Å" /> | ||
| - | '''REFINED STRUCTURE OF THE NICOTINIC ACETYLCHOLINE RECEPTOR AT 4A RESOLUTION.'''<br /> | ||
| - | == | + | ==REFINED STRUCTURE OF THE NICOTINIC ACETYLCHOLINE RECEPTOR AT 4A RESOLUTION.== |
| + | <SX load='2bg9' size='340' side='right' viewer='molstar' caption='[[2bg9]], [[Resolution|resolution]] 4.00Å' scene=''> | ||
| + | == Structural highlights == | ||
| + | <table><tr><td colspan='2'>[[2bg9]] is a 5 chain structure with sequence from [https://en.wikipedia.org/wiki/Torpedo_marmorata Torpedo marmorata]. The November 2005 RCSB PDB [https://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/index.html Molecule of the Month] feature on ''Acetylcholine Receptor'' by David S. Goodsell is [https://dx.doi.org/10.2210/rcsb_pdb/mom_2005_11 10.2210/rcsb_pdb/mom_2005_11]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2BG9 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2BG9 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]] 4Å</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=2bg9 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2bg9 OCA], [https://pdbe.org/2bg9 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2bg9 RCSB], [https://www.ebi.ac.uk/pdbsum/2bg9 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2bg9 ProSAT]</span></td></tr> | ||
| + | </table> | ||
| + | == 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. | ||
| + | == 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/bg/2bg9_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=2bg9 ConSurf]. | ||
| + | <div style="clear:both"></div> | ||
| + | <div style="background-color:#fffaf0;"> | ||
| + | == Publication Abstract from PubMed == | ||
We present a refined model of the membrane-associated Torpedo acetylcholine (ACh) receptor at 4A resolution. An improved experimental density map was obtained from 342 electron images of helical tubes, and the refined structure was derived to an R-factor of 36.7% (R(free) 37.9%) by standard crystallographic methods, after placing the densities corresponding to a single molecule into an artificial unit cell. The agreement between experimental and calculated phases along the helical layer-lines was used to monitor progress in the refinement and to give an independent measure of the accuracy. The atomic model allowed a detailed description of the whole receptor in the closed-channel form, including the ligand-binding and intracellular domains, which have not previously been interpreted at a chemical level. We confirm that the two ligand-binding alpha subunits have a different extended conformation from the three other subunits in the closed channel, and identify several interactions on both pairs of subunit interfaces, and within the alpha subunits, which may be responsible for their "distorted" structures. The ACh-coordinating amino acid side-chains of the alpha subunits are far apart in the closed channel, indicating that a localised rearrangement, involving closure of loops B and C around the bound ACh molecule, occurs upon activation. A comparison of the structure of the alpha subunit with that of AChBP having ligand present, suggests how the localised rearrangement overcomes the distortions and initiates the rotational movements associated with opening of the channel. Both vestibules of the channel are strongly electronegative, providing a cation-stabilising environment at either entrance of the membrane pore. Access to the pore on the intracellular side is further influenced by narrow lateral windows, which would be expected to screen out electrostatically ions of the wrong charge and size. | We present a refined model of the membrane-associated Torpedo acetylcholine (ACh) receptor at 4A resolution. An improved experimental density map was obtained from 342 electron images of helical tubes, and the refined structure was derived to an R-factor of 36.7% (R(free) 37.9%) by standard crystallographic methods, after placing the densities corresponding to a single molecule into an artificial unit cell. The agreement between experimental and calculated phases along the helical layer-lines was used to monitor progress in the refinement and to give an independent measure of the accuracy. The atomic model allowed a detailed description of the whole receptor in the closed-channel form, including the ligand-binding and intracellular domains, which have not previously been interpreted at a chemical level. We confirm that the two ligand-binding alpha subunits have a different extended conformation from the three other subunits in the closed channel, and identify several interactions on both pairs of subunit interfaces, and within the alpha subunits, which may be responsible for their "distorted" structures. The ACh-coordinating amino acid side-chains of the alpha subunits are far apart in the closed channel, indicating that a localised rearrangement, involving closure of loops B and C around the bound ACh molecule, occurs upon activation. A comparison of the structure of the alpha subunit with that of AChBP having ligand present, suggests how the localised rearrangement overcomes the distortions and initiates the rotational movements associated with opening of the channel. Both vestibules of the channel are strongly electronegative, providing a cation-stabilising environment at either entrance of the membrane pore. Access to the pore on the intracellular side is further influenced by narrow lateral windows, which would be expected to screen out electrostatically ions of the wrong charge and size. | ||
| - | + | Refined structure of the nicotinic acetylcholine receptor at 4A resolution.,Unwin N J Mol Biol. 2005 Mar 4;346(4):967-89. Epub 2005 Jan 25. PMID:15701510<ref>PMID:15701510</ref> | |
| - | + | ||
| - | + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |
| - | + | </div> | |
| + | <div class="pdbe-citations 2bg9" style="background-color:#fffaf0;"></div> | ||
| + | |||
| + | ==See Also== | ||
| + | *[[Acetyl choline receptor 3D structures|Acetyl choline receptor 3D structures]] | ||
| + | *[[Ionotropic receptors|Ionotropic receptors]] | ||
| + | *[[Nicotinic Acetylcholine Receptor|Nicotinic Acetylcholine Receptor]] | ||
| + | *[[5-hydroxytryptamine receptor|5-hydroxytryptamine receptor]] | ||
| + | == References == | ||
| + | <references/> | ||
| + | __TOC__ | ||
| + | </SX> | ||
[[Category: Acetylcholine Receptor]] | [[Category: Acetylcholine Receptor]] | ||
| - | [[Category: | + | [[Category: Large Structures]] |
| + | [[Category: RCSB PDB Molecule of the Month]] | ||
[[Category: Torpedo marmorata]] | [[Category: Torpedo marmorata]] | ||
| - | [[Category: Unwin | + | [[Category: Unwin N]] |
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Current revision
REFINED STRUCTURE OF THE NICOTINIC ACETYLCHOLINE RECEPTOR AT 4A RESOLUTION.
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