Ion conduction pore is conserved among potassium channels.
Potassium channels, a group of specialized membrane proteins, enable K+ ions to flow selectively across cell membranes. Transmembrane K+ currents underlie electrical signalling in neurons and other excitable cells. The atomic structure of a bacterial K+ channel pore has been solved by means of X-ray crystallography. To the extent that the prokaryotic pore is representative of other K+ channels, this landmark achievement has profound implications for our general understanding of K+ channels. But serious doubts have been raised concerning whether the prokaryotic K+ channel pore does actually represent those of eukaryotes. Here we have addressed this fundamental issue by substituting the prokaryotic pore into eukaryotic voltage-gated and inward-rectifier K+ channels. The resulting chimaeras retain the respective functional hallmarks of the eukaryotic channels, which indicates that the ion conduction pore is indeed conserved among K+ channels.
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Department of Physiology, University of Pennsylvania, Philadelphia 19104, USA. zhelu@mail.med.upenn.edu
Klem
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AM
Ramu
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Y
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D003001:Cloning, Molecular; D017124:Conserved Sequence; D018360:Crystallography, X-Ray; D005057:Eukaryotic Cells; D015640:Ion Channel Gating; D017136:Ion Transport; D008969:Molecular Sequence Data; D011188:Potassium / Q000378:metabolism; D015221:Potassium Channels / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D024661:Potassium Channels, Inwardly Rectifying / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D011387:Prokaryotic Cells; D011487:Protein Conformation; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D051637:Shaker Superfamily of Potassium Channels; D013045:Species Specificity; D013329:Structure-Activity Relationship
D001426:Bacterial Proteins; D015221:Potassium Channels; D024661:Potassium Channels, Inwardly Rectifying; D011993:Recombinant Fusion Proteins; D051637:Shaker Superfamily of Potassium Channels; C107790:prokaryotic potassium channel; D011188:Potassium