Department of Anesthesiology

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High-Resolution Cryoelectron Microscopy Structure of the Cyclic Nucleotide-Modulated Potassium Channel MloK1 in a Lipid Bilayer.

TitleHigh-Resolution Cryoelectron Microscopy Structure of the Cyclic Nucleotide-Modulated Potassium Channel MloK1 in a Lipid Bilayer.
Publication TypeJournal Article
Year of Publication2018
AuthorsKowal J, Biyani N, Chami M, Scherer S, Rzepiela AJ, Baumgartner P, Upadhyay V, Nimigean CM, Stahlberg H
JournalStructure
Volume26
Issue1
Pagination20-27.e3
Date Published2018 Jan 02
ISSN1878-4186
Abstract

Eukaryotic cyclic nucleotide-modulated channels perform their diverse physiological roles by opening and closing their pores to ions in response to cyclic nucleotide binding. We here present a structural model for the cyclic nucleotide-modulated potassium channel homolog from Mesorhizobium loti, MloK1, determined from 2D crystals in the presence of lipids. Even though crystals diffract electrons to only ∼10 Å, using cryoelectron microscopy (cryo-EM) and recently developed computational methods, we have determined a 3D map of full-length MloK1 in the presence of cyclic AMP (cAMP) at ∼4.5 Å isotropic 3D resolution. The structure provides a clear picture of the arrangement of the cyclic nucleotide-binding domains with respect to both the pore and the putative voltage sensor domains when cAMP is bound, and reveals a potential gating mechanism in the context of the lipid-embedded channel.

DOI10.1016/j.str.2017.11.012
Alternate JournalStructure
PubMed ID29249605