title: Structure of the cytoplasmic beta subunit-T1 assembly of voltage-dependent K+ channels.
abstract: The structure of the cytoplasmic assembly of voltage-dependent K+ channels was solved by x-ray crystallography at 2.1 angstrom resolution. The assembly includes the cytoplasmic (T1) domain of the integral membrane alpha subunit together with the oxidoreductase beta subunit in a fourfold symmetric T1(4)beta4 complex. An electrophysiological assay showed that this complex is oriented with four T1 domains facing the transmembrane pore and four beta subunits facing the cytoplasm. The transmembrane pore communicates with the cytoplasm through lateral, negatively charged openings above the T1(4)beta4 complex. The inactivation peptides of voltage-dependent K(+) channels reach their site of action by entering these openings.
authors.affiliation: Howard Hughes Medical Institute and Laboratory of Molecular Neurobiology and Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Gulbis
authors.forename: M
authors.initials: M
authors.lastname: Zhou
authors.forename: S
authors.initials: S
authors.lastname: Mann
authors.forename: R
authors.initials: R
authors.lastname: MacKinnon
mesh_terms: D000818:Animals; D002460:Cell Line; D018360:Crystallography, X-Ray; D003593:Cytoplasm / Q000737:chemistry; D051662:Kv1.1 Potassium Channel; D051665:Kv1.4 Potassium Channel; D046911:Macromolecular Substances; D008958:Models, Molecular; D009154:Mutation; D009865:Oocytes; D010088:Oxidoreductases / Q000737:chemistry / Q000378:metabolism; D018408:Patch-Clamp Techniques; D010455:Peptides / Q000378:metabolism; D015221:Potassium Channels / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D024642:Potassium Channels, Voltage-Gated; D011487:Protein Conformation; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D014981:Xenopus
chemical_list: C496979:Kcna4 protein, rat; D051665:Kv1.4 Potassium Channel; D046911:Macromolecular Substances; D010455:Peptides; D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated; D011993:Recombinant Fusion Proteins; D051662:Kv1.1 Potassium Channel; D010088:Oxidoreductases