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| | <StructureSection load='6m84' size='340' side='right'caption='[[6m84]], [[Resolution|resolution]] 2.81Å' scene=''> | | <StructureSection load='6m84' size='340' side='right'caption='[[6m84]], [[Resolution|resolution]] 2.81Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[6m84]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Chick Chick]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6M84 OCA]. For a <b>guided tour on the structure components</b> use [http://proteopedia.org/fgij/fg.htm?mol=6M84 FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[6m84]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Gallus_gallus Gallus gallus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6M84 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6M84 FirstGlance]. <br> |
| - | </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>, <scene name='pdbligand=LMT:DODECYL-BETA-D-MALTOSIDE'>LMT</scene>, <scene name='pdbligand=PIO:[(2R)-2-OCTANOYLOXY-3-[OXIDANYL-[(1R,2R,3S,4R,5R,6S)-2,3,6-TRIS(OXIDANYL)-4,5-DIPHOSPHONOOXY-CYCLOHEXYL]OXY-PHOSPHORYL]OXY-PROPYL]+OCTANOATE'>PIO</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]] 2.81Å</td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">KCNJ12 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9031 CHICK])</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>, <scene name='pdbligand=LMT:DODECYL-BETA-D-MALTOSIDE'>LMT</scene>, <scene name='pdbligand=PIO:[(2R)-2-OCTANOYLOXY-3-[OXIDANYL-[(1R,2R,3S,4R,5R,6S)-2,3,6-TRIS(OXIDANYL)-4,5-DIPHOSPHONOOXY-CYCLOHEXYL]OXY-PHOSPHORYL]OXY-PROPYL]+OCTANOATE'>PIO</scene></td></tr> |
| - | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://proteopedia.org/fgij/fg.htm?mol=6m84 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6m84 OCA], [http://pdbe.org/6m84 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6m84 RCSB], [http://www.ebi.ac.uk/pdbsum/6m84 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6m84 ProSAT]</span></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=6m84 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6m84 OCA], [https://pdbe.org/6m84 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6m84 RCSB], [https://www.ebi.ac.uk/pdbsum/6m84 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6m84 ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/KCJ12_CHICK KCJ12_CHICK]] Inward rectifying potassium channel that is activated by phosphatidylinositol 4,5-bisphosphate and that probably participates in controlling the resting membrane potential in electrically excitable cells. Inward rectifier potassium channels are characterized by a greater tendency to allow potassium to flow into the cell rather than out of it. The inward rectification is probably due to the blockage of outward current by cytoplasmic polyamines and/or magnesium ions.<ref>PMID:20019282</ref> <ref>PMID:21874019</ref> | + | [https://www.uniprot.org/uniprot/KCJ12_CHICK KCJ12_CHICK] Inward rectifying potassium channel that is activated by phosphatidylinositol 4,5-bisphosphate and that probably participates in controlling the resting membrane potential in electrically excitable cells. Inward rectifier potassium channels are characterized by a greater tendency to allow potassium to flow into the cell rather than out of it. The inward rectification is probably due to the blockage of outward current by cytoplasmic polyamines and/or magnesium ions.<ref>PMID:20019282</ref> <ref>PMID:21874019</ref> |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Chick]] | + | [[Category: Gallus gallus]] |
| | [[Category: Large Structures]] | | [[Category: Large Structures]] |
| - | [[Category: Lee, S J]] | + | [[Category: Lee S-J]] |
| - | [[Category: Nichols, C G]] | + | [[Category: Nichols CG]] |
| - | [[Category: Ren, F]] | + | [[Category: Ren F]] |
| - | [[Category: Yuan, P]] | + | [[Category: Yuan P]] |
| - | [[Category: Complex]]
| + | |
| - | [[Category: Kir 2 2 force open mutant]]
| + | |
| - | [[Category: Metal transport]]
| + | |
| Structural highlights
Function
KCJ12_CHICK Inward rectifying potassium channel that is activated by phosphatidylinositol 4,5-bisphosphate and that probably participates in controlling the resting membrane potential in electrically excitable cells. Inward rectifier potassium channels are characterized by a greater tendency to allow potassium to flow into the cell rather than out of it. The inward rectification is probably due to the blockage of outward current by cytoplasmic polyamines and/or magnesium ions.[1] [2]
Publication Abstract from PubMed
Potassium ion conduction through open potassium channels is essential to control of membrane potentials in all cells. To elucidate the open conformation and hence the mechanism of K+ ion conduction in the classic inward rectifier Kir2.2, we introduced a negative charge (G178D) at the crossing point of the inner helix bundle, the location of ligand-dependent gating. This "forced open" mutation generated channels that were active even in the complete absence of phosphatidylinositol-4,5-bisphosphate (PIP2), an otherwise essential ligand for Kir channel opening. Crystal structures were obtained at a resolution of 3.6 A without PIP2 bound, or 2.8 A in complex with PIP2. The latter revealed a slight widening at the helix bundle crossing (HBC) through backbone movement. MD simulations showed that subsequent spontaneous wetting of the pore through the HBC gate region allowed K+ ion movement across the HBC and conduction through the channel. Further simulations reveal atomistic details of the opening process and highlight the role of pore-lining acidic residues in K+ conduction through Kir2 channels.
Atomistic basis of opening and conduction in mammalian inward rectifier potassium (Kir2.2) channels.,Zangerl-Plessl EM, Lee SJ, Maksaev G, Bernsteiner H, Ren F, Yuan P, Stary-Weinzinger A, Nichols CG J Gen Physiol. 2020 Jan 6;152(1). pii: jgp.201912422. doi: 10.1085/jgp.201912422. PMID:31744859[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Tao X, Avalos JL, Chen J, MacKinnon R. Crystal structure of the eukaryotic strong inward-rectifier K+ channel Kir2.2 at 3.1 A resolution. Science. 2009 Dec 18;326(5960):1668-74. PMID:20019282 doi:326/5960/1668
- ↑ Hansen SB, Tao X, Mackinnon R. Structural basis of PIP(2) activation of the classical inward rectifier K(+) channel Kir2.2. Nature. 2011 Aug 28. doi: 10.1038/nature10370. PMID:21874019 doi:10.1038/nature10370
- ↑ Zangerl-Plessl EM, Lee SJ, Maksaev G, Bernsteiner H, Ren F, Yuan P, Stary-Weinzinger A, Nichols CG. Atomistic basis of opening and conduction in mammalian inward rectifier potassium (Kir2.2) channels. J Gen Physiol. 2020 Jan 6;152(1). pii: jgp.201912422. doi: 10.1085/jgp.201912422. PMID:31744859 doi:http://dx.doi.org/10.1085/jgp.201912422
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