Protein Structure and Ion Binding in Potassium Selective Channels
Potassium channels play a central role in a number of biological processes, most classically the action potential of excitable cells in multicellular organisms. These channels are defined by their selective conduction of potassium to the exclusion of other monovalent ions as governed by a common sequence and structural motif, the selectivity filter. This structure, made of backbone carbonyls and threonine side chains, directly coordinates the ions as they diffuse through the channel and appears central to this sub-angstrom discrimination between cations. Utilizing the non-selective Sodium and Potassium conducting channel (NaK) as a structural scaffold the mechanisms of both ion selectivity and formation of this selective structure are examined.
Sodium-Potassium-Exchanging ATPase, Potassium, Models, Molecular
University of Texas Southwestern Medical Center
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