2ih3
From Proteopedia
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| , resolution 1.72Å | |||||||
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| Ligands: | , , | ||||||
| Gene: | kcsA, skc1 (Streptomyces lividans) | ||||||
| Related: | 2IH1
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Ion selectivity in a semi-synthetic K+ channel locked in the conductive conformation
Overview
Potassium channels are K+-selective protein pores in cell membrane. The selectivity filter is the functional unit that allows K+ channels to distinguish potassium (K+) and sodium (Na+) ions. The filter's structure depends on whether K+ or Na+ ions are bound inside it. We synthesized a K+ channel containing the d-enantiomer of alanine in place of a conserved glycine and found by x-ray crystallography that its filter maintains the K+ (conductive) structure in the presence of Na+ and very low concentrations of K+. This channel conducts Na+ in the absence of K+ but not in the presence of K+. These findings demonstrate that the ability of the channel to adapt its structure differently to K+ and Na+ is a fundamental aspect of ion selectivity, as is the ability of multiple K+ ions to compete effectively with Na+ for the conductive filter.
About this Structure
2IH3 is a Single protein structure of sequence from Mus musculus and Streptomyces lividans. Full crystallographic information is available from OCA.
Reference
Ion selectivity in a semisynthetic K+ channel locked in the conductive conformation., Valiyaveetil FI, Leonetti M, Muir TW, Mackinnon R, Science. 2006 Nov 10;314(5801):1004-7. PMID:17095703
Page seeded by OCA on Mon Mar 31 03:44:15 2008
