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Changing perspectives on how the permeation pathway through potassium channels is regulated
Katrina A Black1,2, Ruitao Jin3, Sitong He3
1Structural Biology Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, 3052, Australia.
Abstract:
The primary means by which ion permeation through potassium channels is controlled, and the key to selective intervention in a range of pathophysiological conditions, is the process by which channels switch between non-conducting and conducting states. Conventionally, this has been explained by a steric mechanism in which the pore alternates between two conformations: a 'closed' state in which the conduction pathway is occluded and an 'open' state in which the pathway is sufficiently wide to accommodate fully hydrated ions. Recently, however, 'non-canonical' mechanisms have been proposed for some classes of K+ channels. The purpose of this review is to illuminate structural and dynamic relationships underpinning permeation control in K+ channels, indicating where additional data might resolve some of the remaining issues.
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