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3eam
From Proteopedia
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==An open-pore structure of a bacterial pentameric ligand-gated ion channel== | ==An open-pore structure of a bacterial pentameric ligand-gated ion channel== | ||
| - | <StructureSection load='3eam' size='340' side='right' caption='[[3eam]], [[Resolution|resolution]] 2.90Å' scene=''> | + | <StructureSection load='3eam' size='340' side='right'caption='[[3eam]], [[Resolution|resolution]] 2.90Å' scene=''> |
== Structural highlights == | == Structural highlights == | ||
| - | <table><tr><td colspan='2'>[[3eam]] is a 5 chain structure with sequence from [ | + | <table><tr><td colspan='2'>[[3eam]] is a 5 chain structure with sequence from [https://en.wikipedia.org/wiki/Gloeobacter_violaceus Gloeobacter violaceus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3EAM OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3EAM FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=LMT:DODECYL-BETA-D-MALTOSIDE'>LMT</scene>, <scene name='pdbligand=PC1:1,2-DIACYL-SN-GLYCERO-3-PHOSPHOCHOLINE'>PC1</scene> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.9Å</td></tr> |
| - | + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=LMT:DODECYL-BETA-D-MALTOSIDE'>LMT</scene>, <scene name='pdbligand=PC1:1,2-DIACYL-SN-GLYCERO-3-PHOSPHOCHOLINE'>PC1</scene></td></tr> | |
| - | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[ | + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=3eam FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3eam OCA], [https://pdbe.org/3eam PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3eam RCSB], [https://www.ebi.ac.uk/pdbsum/3eam PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3eam ProSAT]</span></td></tr> |
</table> | </table> | ||
== Function == | == Function == | ||
| - | [ | + | [https://www.uniprot.org/uniprot/GLIC_GLOVI GLIC_GLOVI] Cationic channel with similar permeabilities for Na(+) and K(+), that is activated by an increase of the proton concentration on the extracellular side. Displays no permeability for chloride ions. Shows slow kinetics of activation, no desensitization and a single channel conductance of 8 pS. Might contribute to adaptation to external pH change.<ref>PMID:17167423</ref> |
== Evolutionary Conservation == | == Evolutionary Conservation == | ||
[[Image:Consurf_key_small.gif|200px|right]] | [[Image:Consurf_key_small.gif|200px|right]] | ||
Check<jmol> | Check<jmol> | ||
<jmolCheckbox> | <jmolCheckbox> | ||
| - | <scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/ea/3eam_consurf.spt"</scriptWhenChecked> | + | <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/ea/3eam_consurf.spt"</scriptWhenChecked> |
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | ||
<text>to colour the structure by Evolutionary Conservation</text> | <text>to colour the structure by Evolutionary Conservation</text> | ||
</jmolCheckbox> | </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/ | + | </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=3eam ConSurf]. |
<div style="clear:both"></div> | <div style="clear:both"></div> | ||
| - | <div style="background-color:#fffaf0;"> | ||
| - | == Publication Abstract from PubMed == | ||
| - | Pentameric ligand-gated ion channels from the Cys-loop family mediate fast chemo-electrical transduction, but the mechanisms of ion permeation and gating of these membrane proteins remain elusive. Here we present the X-ray structure at 2.9 A resolution of the bacterial Gloeobacter violaceus pentameric ligand-gated ion channel homologue (GLIC) at pH 4.6 in an apparently open conformation. This cationic channel is known to be permanently activated by protons. The structure is arranged as a funnel-shaped transmembrane pore widely open on the outer side and lined by hydrophobic residues. On the inner side, a 5 A constriction matches with rings of hydrophilic residues that are likely to contribute to the ionic selectivity. Structural comparison with ELIC, a bacterial homologue from Erwinia chrysanthemi solved in a presumed closed conformation, shows a wider pore where the narrow hydrophobic constriction found in ELIC is removed. Comparative analysis of GLIC and ELIC reveals, in concert, a rotation of each extracellular beta-sandwich domain as a rigid body, interface rearrangements, and a reorganization of the transmembrane domain, involving a tilt of the M2 and M3 alpha-helices away from the pore axis. These data are consistent with a model of pore opening based on both quaternary twist and tertiary deformation. | ||
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| - | X-ray structure of a pentameric ligand-gated ion channel in an apparently open conformation.,Bocquet N, Nury H, Baaden M, Le Poupon C, Changeux JP, Delarue M, Corringer PJ Nature. 2009 Jan 1;457(7225):111-4. Epub 2008 Nov 5. PMID:18987633<ref>PMID:18987633</ref> | ||
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| - | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | ||
| - | </div> | ||
==See Also== | ==See Also== | ||
| - | *[[Ion channels|Ion channels]] | + | *[[Ion channels 3D structures|Ion channels 3D structures]] |
== References == | == References == | ||
<references/> | <references/> | ||
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</StructureSection> | </StructureSection> | ||
[[Category: Gloeobacter violaceus]] | [[Category: Gloeobacter violaceus]] | ||
| - | [[Category: Baaden | + | [[Category: Large Structures]] |
| - | [[Category: Bocquet | + | [[Category: Baaden M]] |
| - | [[Category: Changeux | + | [[Category: Bocquet N]] |
| - | [[Category: Corringer | + | [[Category: Changeux JP]] |
| - | [[Category: Delarue | + | [[Category: Corringer PJ]] |
| - | [[Category: | + | [[Category: Delarue M]] |
| - | + | [[Category: Le Poupon C]] | |
| - | [[Category: | + | [[Category: Nury H]] |
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Current revision
An open-pore structure of a bacterial pentameric ligand-gated ion channel
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