ジャーナル: Elife / 年: 2018 タイトル: Single-particle cryo-EM structure of a voltage-activated potassium channel in lipid nanodiscs. 著者: Doreen Matthies / Chanhyung Bae / Gilman Es Toombes / Tara Fox / Alberto Bartesaghi / Sriram Subramaniam / Kenton Jon Swartz / 要旨: Voltage-activated potassium (Kv) channels open to conduct K ions in response to membrane depolarization, and subsequently enter non-conducting states through distinct mechanisms of inactivation. X- ...Voltage-activated potassium (Kv) channels open to conduct K ions in response to membrane depolarization, and subsequently enter non-conducting states through distinct mechanisms of inactivation. X-ray structures of detergent-solubilized Kv channels appear to have captured an open state even though a non-conducting C-type inactivated state would predominate in membranes in the absence of a transmembrane voltage. However, structures for a voltage-activated ion channel in a lipid bilayer environment have not yet been reported. Here we report the structure of the Kv1.2-2.1 paddle chimera channel reconstituted into lipid nanodiscs using single-particle cryo-electron microscopy. At a resolution of ~3 Å for the cytosolic domain and ~4 Å for the transmembrane domain, the structure determined in nanodiscs is similar to the previously determined X-ray structure. Our findings show that large differences in structure between detergent and lipid bilayer environments are unlikely, and enable us to propose possible structural mechanisms for C-type inactivation.
UniProtKB: Potassium voltage-gated channel subfamily A member 2, Potassium voltage-gated channel subfamily B member 2, Potassium voltage-gated channel subfamily A member 2
凍結剤: ETHANE / チャンバー内湿度: 88 % / チャンバー内温度: 277.15 K / 装置: LEICA EM GP 詳細: A 3 microliter sample was applied to a plasma-cleaned grid and blotted for 10 seconds..