Potassium channels: structures, models, simulations.
Potassium channels have been studied intensively in terms of the relationship between molecular structure and physiological function. They provide an opportunity to integrate structural and computational studies in order to arrive at an atomic resolution description of mechanism. We review recent progress in K channel structural studies, focussing on the bacterial channel KcsA. Structural studies can be extended via use of computational (i.e. molecular simulation) approaches in order to provide a perspective on aspects of channel function such as permeation, selectivity, block and gating. Results from molecular dynamics simulations are shown to be in good agreement with recent structural studies of KcsA in terms of the interactions of K(+) ions with binding sites within the selectivity filter of the channel, and in revealing the importance of filter flexibility in channel function. We discuss how the KcsA structure may be used as a template for developing structural models of other families of K channels. Progress in this area is explored via two examples: inward rectifier (Kir) and voltage-gated (Kv) potassium channels. A brief account of structural studies of ancillary domains and subunits of K channels is provided.
Sansom
Mark S P
MS
Laboratory of Molecular Biophysics, Department of Biochemistry, The University of Oxford, The Rex Richards Building, South Parks Road, Oxford, UK. mark@biop.ox.ac.uk
Shrivastava
Indira H
IH
Bright
Joanne N
JN
Tate
John
J
Capener
Charlotte E
CE
Biggin
Philip C
PC
D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry* / Q000502:physiology*; D001665:Binding Sites; D002414:Cations, Monovalent / Q000737:chemistry; D003198:Computer Simulation; D018360:Crystallography, X-Ray; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry* / Q000502:physiology; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015394:Molecular Structure; D015221:Potassium Channels / Q000737:chemistry* / Q000502:physiology*; D024661:Potassium Channels, Inwardly Rectifying / Q000737:chemistry; D024642:Potassium Channels, Voltage-Gated / Q000737:chemistry; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D013329:Structure-Activity Relationship
D001426:Bacterial Proteins; D002414:Cations, Monovalent; D008565:Membrane Proteins; D015221:Potassium Channels; D024661:Potassium Channels, Inwardly Rectifying; D024642:Potassium Channels, Voltage-Gated; C107790:prokaryotic potassium channel