Single-particle cryo-EM structure of a voltage-activated potassium channel in lipid nanodiscs.

Published

Journal Article

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.

Full Text

Duke Authors

Cited Authors

  • Matthies, D; Bae, C; Toombes, GE; Fox, T; Bartesaghi, A; Subramaniam, S; Swartz, KJ

Published Date

  • August 15, 2018

Published In

Volume / Issue

  • 7 /

PubMed ID

  • 30109985

Pubmed Central ID

  • 30109985

Electronic International Standard Serial Number (EISSN)

  • 2050-084X

International Standard Serial Number (ISSN)

  • 2050-084X

Digital Object Identifier (DOI)

  • 10.7554/eLife.37558

Language

  • eng