StructuralclassificationofK+channelsubunitsA general classification of Kt channels intofamiliesisbased upontheprimaryaminoacidsequenceofthepore-containingsubunit.Three groups with six, four, or two putativetransmembranesegmentsarerecognizedA.Sixtransmembraneone-poreNativevoltage-gated K+Clonescurrentchannels(Shaker-Kv1-Kv9IKDR,KTO,KURHERGIKrlike)containingsixKVLQTIKshSloBKcaIKca1IKcatransmembraneregions(S1-S6)NH3with a single pore;
Structural classification of K+ channel subunits A general classification of K+ channels into families is based upon the primary amino acid sequence of the porecontaining subunit. Three groups with six, four, or two putative transmembrane segments are recognized. voltage-gated K+ channels (Shakerlike) containing six transmembrane regions (S1-S6) with a single pore;
The tetrameric 6TM architecture of the K+ channel familySelectivityfilterPorehelixOutOuterhelix(S5)BundlecrossingInnerholix(S6)Kv1.x-4.xCNG,KCa-HCN,eag/erg,BK,SKMRP,BKpS1-S4S1-S4voltageBK:S0volingesensosensorPASC-terminaldomainsensor(erg)domainl-tetramer
The tetrameric 6TM architecture of the K+ channel family
ArchitecturalfeaturesofK+channelsimportantforionpermeation(3)Customizedoxygencages(4)Multipleionoccupancy2)Helixdipoles人(1)PlentyofwaterO
Architectural features of K+ channels important for ion permeation K
The conformationalchanges that gatethe Kt channel poreS6gateThe three best understoodconformational changesforclosing potassium channelsBall-and-chainSelectivityfiltergategateGreen:the selectivity filterBlue: an auto-inhibitory peptide
The conformational changes that gate the K+ channel pore The three best understood conformational changes for closing potassium channels Green: the selectivity filter Blue: an auto-inhibitory peptide
Two sensor domains that govern gatingin the K+ channel family
Two sensor domains that govern gating in the K+ channel family K