3agw | pdb_00003agw

Crystal Structure of the Cytoplasmic Domain of G-Protein-Gated Inward Rectifier Potassium Channel Kir3.2 in the absence of Na+

spinqualitylabelsall models 3agw, resolution 2.20Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3agw is a 1 chain structure with sequence from Lk3 transgenic mice. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: EOH, MG Related: 2e4f Gene: Kcnj6 (LK3 transgenic mice) Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT 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 Inward rectifier K(+) (Kir) channels are activated by phosphatidylinositol-(4,5)-bisphosphate (PIP(2)), but G protein-gated Kir (K(G)) channels further require either G protein betagamma subunits (Gbetagamma) or intracellular Na(+) for their activation. To reveal the mechanism(s) underlying this regulation, we compared the crystal structures of the cytoplasmic domain of K(G) channel subunit Kir3.2 obtained in the presence and the absence of Na(+). The Na(+)-free Kir3.2, but not the Na(+)-plus Kir3.2, possessed an ionic bond connecting the N terminus and the CD loop of the C terminus. Functional analyses revealed that the ionic bond between His-69 on the N terminus and Asp-228 on the CD loop, which are known to be critically involved in Gbetagamma- and Na(+)-dependent activation, lowered PIP(2) sensitivity. The conservation of these residues within the K(G) channel family indicates that the ionic bond is a character that maintains the channels in a closed state by controlling the PIP(2) sensitivity. A structural determinant for the control of PIP2 sensitivity in G protein-gated inward rectifier K+ channels.,Inanobe A, Nakagawa A, Matsuura T, Kurachi Y J Biol Chem. 2010 Dec 3;285(49):38517-23. Epub 2010 Sep 29. PMID:20880843 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Potassium Channel

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