2qks
From Proteopedia
(New page: 200px<br /><applet load="2qks" size="350" color="white" frame="true" align="right" spinBox="true" caption="2qks, resolution 2.2Å" /> '''Crystal structure of ...) |
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==Overview== | ==Overview== | ||
| - | The Kir3.1 K(+) channel participates in heart rate control and neuronal | + | The Kir3.1 K(+) channel participates in heart rate control and neuronal excitability through G-protein and lipid signaling pathways. Expression in Escherichia coli has been achieved by replacing three fourths of the transmembrane pore with the pore of a prokaryotic Kir channel, leaving the cytoplasmic pore and membrane interfacial regions of Kir3.1 origin. Two structures were determined at 2.2 A. The selectivity filter is identical to the Streptomyces lividans K(+) channel within error of measurement (r.m.s.d.<0.2 A), suggesting that K(+) selectivity requires extreme conservation of three-dimensional structure. Multiple K(+) ions reside within the pore and help to explain voltage-dependent Mg(2+) and polyamine blockade and strong rectification. Two constrictions, at the inner helix bundle and at the apex of the cytoplasmic pore, may function as gates: in one structure the apex is open and in the other, it is closed. Gating of the apex is mediated by rigid-body movements of the cytoplasmic pore subunits. Phosphatidylinositol 4,5-biphosphate-interacting residues suggest a possible mechanism by which the signaling lipid regulates the cytoplasmic pore. |
==About this Structure== | ==About this Structure== | ||
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==Reference== | ==Reference== | ||
| - | Crystal structure of a Kir3.1-prokaryotic Kir channel chimera., Nishida M, Cadene M, Chait BT, | + | Crystal structure of a Kir3.1-prokaryotic Kir channel chimera., Nishida M, Cadene M, Chait BT, MacKinnon R, EMBO J. 2007 Sep 5;26(17):4005-15. Epub 2007 Aug 16. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17703190 17703190] |
[[Category: Mus musculus, burkholderia xenovornas]] | [[Category: Mus musculus, burkholderia xenovornas]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
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[[Category: selectivity filter]] | [[Category: selectivity filter]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 18:40:04 2008'' |
Revision as of 16:40, 21 February 2008
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Crystal structure of a Kir3.1-prokaryotic Kir channel chimera
Overview
The Kir3.1 K(+) channel participates in heart rate control and neuronal excitability through G-protein and lipid signaling pathways. Expression in Escherichia coli has been achieved by replacing three fourths of the transmembrane pore with the pore of a prokaryotic Kir channel, leaving the cytoplasmic pore and membrane interfacial regions of Kir3.1 origin. Two structures were determined at 2.2 A. The selectivity filter is identical to the Streptomyces lividans K(+) channel within error of measurement (r.m.s.d.<0.2 A), suggesting that K(+) selectivity requires extreme conservation of three-dimensional structure. Multiple K(+) ions reside within the pore and help to explain voltage-dependent Mg(2+) and polyamine blockade and strong rectification. Two constrictions, at the inner helix bundle and at the apex of the cytoplasmic pore, may function as gates: in one structure the apex is open and in the other, it is closed. Gating of the apex is mediated by rigid-body movements of the cytoplasmic pore subunits. Phosphatidylinositol 4,5-biphosphate-interacting residues suggest a possible mechanism by which the signaling lipid regulates the cytoplasmic pore.
About this Structure
2QKS is a Single protein structure of sequence from Mus musculus, burkholderia xenovornas with and as ligands. Full crystallographic information is available from OCA.
Reference
Crystal structure of a Kir3.1-prokaryotic Kir channel chimera., Nishida M, Cadene M, Chait BT, MacKinnon R, EMBO J. 2007 Sep 5;26(17):4005-15. Epub 2007 Aug 16. PMID:17703190
Page seeded by OCA on Thu Feb 21 18:40:04 2008
