3k6n

Crystal structure of the S225E mutant Kir3.1 cytoplasmic pore domain

spinqualitylabelsall models 3k6n, resolution 2.00Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3k6n is a 1 chain structure with sequence from Mus musculus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2Å Ligands: NA Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function KCNJ3_MOUSE This potassium channel is controlled by G proteins. Inward rectifier potassium channels are characterized by a greater tendency to allow potassium to flow into the cell rather than out of it. Their voltage dependence is regulated by the concentration of extracellular potassium; as external potassium is raised, the voltage range of the channel opening shifts to more positive voltages. The inward rectification is mainly due to the blockage of outward current by internal magnesium. This receptor plays a crucial role in regulating the heartbeat. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Strong voltage sensitivity of inward-rectifier K(+) (Kir) channels has been hypothesized to arise primarily from an intracellular blocker displacing up to five K(+) ions from the wide, intracellular part of the ion conduction pore outwardly across the narrow ion-selectivity filter. The validity of this hypothesis depends on two assumptions: (i) that five ion sites are located intracellular to the filter and (ii) that the blocker can force essentially unidirectional K(+) movement in a pore region generally wider than the combined dimensions of the blocker plus a K(+) ion. Here we present a crystal structure of the cytoplasmic portion of a Kir channel with five ions bound and demonstrate that a constriction near the intracellular end of the pore, acting as a gasket, prevents K(+) ions from bypassing the blocker. This heretofore unrecognized 'gasket' ensures that the blocker can effectively displace K(+) ions across the selectivity filter to generate exceedingly strong voltage sensitivity. Physical determinants of strong voltage sensitivity of K(+) channel block.,Xu Y, Shin HG, Szep S, Lu Z Nat Struct Mol Biol. 2009 Dec;16(12):1252-8. Epub 2009 Nov 15. PMID:19915587 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Potassium channel 3D structures

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