View source for 6m85


==Crystal Structure of Inward Rectifier Kir2.2 in a different salt condition==
<StructureSection load='6m85' size='340' side='right'caption='[[6m85]], [[Resolution|resolution]] 2.71&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6m85]] 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=6M85 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6M85 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.71&#8491;</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='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=6m85 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6m85 OCA], [https://pdbe.org/6m85 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6m85 RCSB], [https://www.ebi.ac.uk/pdbsum/6m85 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6m85 ProSAT]</span></td></tr>
</table>
== Function ==
[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;">
== 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<ref>PMID:31744859</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6m85" style="background-color:#fffaf0;"></div>

==See Also==
*[[Potassium channel 3D structures|Potassium channel 3D structures]]
== References ==
<references/>
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</StructureSection>
[[Category: Gallus gallus]]
[[Category: Large Structures]]
[[Category: Lee S-J]]
[[Category: Nichols CG]]