Abstract
The intracellular C-terminal domain structure of a six-transmembrane K+ channel from Escherichia coli has been solved by X-ray crystallography at 2.4 A resolution. The structure is representative of a broad class of domains/proteins that regulate the conductance of K+ (here referred to as RCK domains) in prokaryotic K+ transporters and K+ channels. The RCK domain has a Rossmann-fold topology with unique positions, not commonly conserved among Rossmann-fold proteins, composing a well-conserved salt bridge and a hydrophobic dimer interface. Structure-based amino acid sequence alignments and mutational analysis are used to demonstrate that an RCK domain is also present and is an important component of the gating machinery in eukaryotic large-conductance Ca2+ activated K+ channels.
Publication types
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Comparative Study
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Amino Acid Sequence
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Animals
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Binding Sites
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Carrier Proteins / chemistry
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Crystallization
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Crystallography, X-Ray
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Databases, Factual
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Electric Conductivity
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Escherichia coli / chemistry*
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Female
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Gene Expression
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Humans
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Large-Conductance Calcium-Activated Potassium Channels
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Membrane Proteins / chemistry
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Models, Molecular
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Molecular Sequence Data
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Oocytes / metabolism
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Potassium Channels / chemistry*
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Potassium Channels / genetics
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Potassium Channels, Calcium-Activated*
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Protein Structure, Tertiary
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Receptor, trkA*
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Sequence Alignment
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Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
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Transfection
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Xenopus
Substances
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Carrier Proteins
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Large-Conductance Calcium-Activated Potassium Channels
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Membrane Proteins
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Potassium Channels
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Potassium Channels, Calcium-Activated
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Receptor, trkA