1b4i

Control of K+ Channel Gating by protein phosphorylation: structural switches of the inactivation gate, NMR, 22 structures

spinqualitylabelsall models 1b4i Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1b4i is a 1 chain structure with sequence from Homo sapiens. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Solution NMR, 23 models Ligands: SEP Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function KCNC4_HUMAN This protein mediates the voltage-dependent potassium ion permeability of excitable membranes. Assuming opened or closed conformations in response to the voltage difference across the membrane, the protein forms a potassium-selective channel through which potassium ions may pass in accordance with their electrochemical gradient. Publication Abstract from PubMed Fast N-type inactivation of voltage-dependent potassium (Kv) channels controls membrane excitability and signal propagation in central neurons and occurs by a 'ball-and-chain'-type mechanism. In this mechanism an N-terminal protein domain (inactivation gate) occludes the pore from the cytoplasmic side. In Kv3.4 channels, inactivation is not fixed but is dynamically regulated by protein phosphorylation. Phosphorylation of several identified serine residues on the inactivation gate leads to reduction or removal of fast inactivation. Here, we investigate the structure-function basis of this phospho-regulation with nuclear magnetic resonance (NMR) spectroscopy and patch-clamp recordings using synthetic inactivation domains (ID). The dephosphorylated ID exhibited compact structure and displayed high-affinity binding to its receptor. Phosphorylation of serine residues in the N- or C-terminal half of the ID resulted in a loss of overall structural stability. However, depending on the residue(s) phosphorylated, distinct structural elements remained stable. These structural changes correlate with the distinct changes in binding and unbinding kinetics underlying the reduced inactivation potency of phosphorylated IDs. Control of K+ channel gating by protein phosphorylation: structural switches of the inactivation gate.,Antz C, Bauer T, Kalbacher H, Frank R, Covarrubias M, Kalbitzer HR, Ruppersberg JP, Baukrowitz T, Fakler B Nat Struct Biol. 1999 Feb;6(2):146-50. PMID:10048926 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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