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Title | Single-particle cryo-EM structure of a voltage-activated potassium channel in lipid nanodiscs. |
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Journal, issue, pages | Elife, Vol. 7, Year 2018 |
Publish date | Aug 15, 2018 |
Authors | Doreen Matthies / Chanhyung Bae / Gilman Es Toombes / Tara Fox / Alberto Bartesaghi / Sriram Subramaniam / Kenton Jon Swartz / |
PubMed Abstract | 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. |
External links | Elife / PubMed:30109985 / PubMed Central |
Methods | EM (single particle) |
Resolution | 3.0 - 4.0 Å |
Structure data | EMDB-9024, PDB-6ebk: |
Chemicals | ChemComp-NAP: ChemComp-HOH: |
Source |
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Keywords | MEMBRANE PROTEIN / transport protein / potassium channel / lipid nanodisc |