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| | ==MthK channel pore E92Q mutant== | | ==MthK channel pore E92Q mutant== |
| - | <StructureSection load='3r65' size='340' side='right' caption='[[3r65]], [[Resolution|resolution]] 1.80Å' scene=''> | + | <StructureSection load='3r65' size='340' side='right'caption='[[3r65]], [[Resolution|resolution]] 1.80Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[3r65]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Metth Metth]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3R65 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3R65 FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[3r65]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Methanothermobacter_thermautotrophicus_str._Delta_H Methanothermobacter thermautotrophicus str. Delta H]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3R65 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3R65 FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=K:POTASSIUM+ION'>K</scene></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.8Å</td></tr> |
| - | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[3ldc|3ldc]]</td></tr> | + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=K:POTASSIUM+ION'>K</scene></td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">mthK, MTH_1520 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=187420 METTH])</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=3r65 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3r65 OCA], [https://pdbe.org/3r65 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3r65 RCSB], [https://www.ebi.ac.uk/pdbsum/3r65 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3r65 ProSAT]</span></td></tr> |
| - | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3r65 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3r65 OCA], [http://pdbe.org/3r65 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=3r65 RCSB], [http://www.ebi.ac.uk/pdbsum/3r65 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=3r65 ProSAT]</span></td></tr> | + | |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/MTHK_METTH MTHK_METTH]] Calcium-gated potassium channel. | + | [https://www.uniprot.org/uniprot/MTHK_METTH MTHK_METTH] Calcium-gated potassium channel. |
| - | <div style="background-color:#fffaf0;">
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| - | == Publication Abstract from PubMed ==
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| - | While selective for K, K channels vary significantly among their rate of ion permeation. Here, we probe the effect of steric hindrance and electrostatics within the ion conduction pathway on K permeation in the MthK K channel using structure-based mutagenesis combined with single-channel electrophysiology and X-ray crystallography. We demonstrate that changes in side-chain size and polarity at Ala88, which forms the constriction point of the open MthK pore, have profound effects on single-channel conductance as well as open probability. We also reveal that the negatively charged Glu92s at the intracellular entrance of the open pore form an electrostatic trap, which stabilizes a hydrated K and facilitates ion permeation. This electrostatic attraction is also responsible for intracellular divalent blockage, which renders the channel inward rectified in the presence of Ca(2). In light of the high structural conservation of the selectivity filter, the size and chemical environment differences within the portion of the ion conduction pathway other than the filter are likely the determinants for the conductance variations among K channels.
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| - | Crucial points within the pore as determinants of K channel conductance and gating.,Shi N, Zeng W, Ye S, Li Y, Jiang Y J Mol Biol. 2011 Aug 5;411(1):27-35. Epub 2011 Apr 30. PMID:21554888<ref>PMID:21554888</ref>
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| - | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br>
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| - | </div>
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| - | <div class="pdbe-citations 3r65" style="background-color:#fffaf0;"></div>
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| | ==See Also== | | ==See Also== |
| - | *[[Potassium Channel|Potassium Channel]] | + | *[[Potassium channel 3D structures|Potassium channel 3D structures]] |
| - | == References ==
| + | |
| - | <references/>
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Metth]] | + | [[Category: Large Structures]] |
| - | [[Category: Jiang, Y]] | + | [[Category: Methanothermobacter thermautotrophicus str. Delta H]] |
| - | [[Category: Li, Y]] | + | [[Category: Jiang Y]] |
| - | [[Category: Shi, N]] | + | [[Category: Li Y]] |
| - | [[Category: Ye, S]] | + | [[Category: Shi N]] |
| - | [[Category: Zeng, W]] | + | [[Category: Ye S]] |
| - | [[Category: Ion channel]]
| + | [[Category: Zeng W]] |
| - | [[Category: Membrane]]
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| - | [[Category: Membrane protein]]
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| - | [[Category: Potassium ion]]
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| - | [[Category: Trans-membrane]]
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