title: Crystal structure of the human two-pore domain potassium channel K2P1.
abstract: Two-pore domain potassium (K(+)) channels (K2P channels) control the negative resting potential of eukaryotic cells and regulate cell excitability by conducting K(+) ions across the plasma membrane. Here, we present the 3.4 angstrom resolution crystal structure of a human K2P channel, K2P1 (TWIK-1). Unlike other K(+) channel structures, K2P1 is dimeric. An extracellular cap domain located above the selectivity filter forms an ion pathway in which K(+) ions flow through side portals. Openings within the transmembrane region expose the pore to the lipid bilayer and are filled with electron density attributable to alkyl chains. An interfacial helix appears structurally poised to affect gating. The structure lays a foundation to further investigate how K2P channels are regulated by diverse stimuli.
authors.affiliation: Structural Biology Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA.
authors.forename: Alexandria N
authors.initials: AN
authors.lastname: Miller
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Long
mesh_terms: D000595:Amino Acid Sequence; D002462:Cell Membrane / Q000737:chemistry; D003460:Crystallization; D018360:Crystallography, X-Ray; D006801:Humans; D015640:Ion Channel Gating; D008051:Lipid Bilayers / Q000737:chemistry; D008564:Membrane Potentials; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011188:Potassium / Q000378:metabolism; D024683:Potassium Channels, Tandem Pore Domain / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation; D055503:Protein Multimerization; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry
chemical_list: C109137:KCNK1 protein, human; D008051:Lipid Bilayers; D024683:Potassium Channels, Tandem Pore Domain; D011994:Recombinant Proteins; D011188:Potassium