1ho2
NMR STRUCTURE OF THE POTASSIUM CHANNEL FRAGMENT L45 IN MICELLES
Structural highlights
FunctionKCNAS_DROME Voltage-dependent potassium channel involved in regulation of sleep need or efficiency. 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.[1] Publication Abstract from PubMedThe propagation of action potentials during neuronal signal transduction in phospholipid membranes is mediated by ion channels, a diverse group of membrane proteins. The S4-S5 linker peptide (S4-S5), that connects the S4 and S5 transmembrane segments of voltage-gated potassium channels is an important region of the Shaker ion-channel protein. Despite its importance, very little is known about its structure. Here we provide evidence for an amphipathic alpha-helical conformation of a synthetic S4-S5 peptide of the voltage-gated Drosophila melanogaster Shaker potassium channel in water/trifluoroethanol and in aqueous phospholipid micelles. The three-dimensional solution structures of the S4-S5 peptide were obtained by high-resolution nuclear magnetic resonance spectroscopy and distance-geometry/simulated-annealing calculations. The detailed structural features are discussed with respect to model studies and available mutagenesis data on the mechanism and selectivity of the potassium channel. Three-dimensional structure of the S4-S5 segment of the Shaker potassium channel.,Ohlenschlager O, Hojo H, Ramachandran R, Gorlach M, Haris PI Biophys J. 2002 Jun;82(6):2995-3002. PMID:12023222[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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