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

Type of publication Peer-reviewed
Publikationsform Original article (peer-reviewed)
Author Kowal Julia, Biyani Nikhil, Chami Mohamed, Scherer Sebastian, Rzepiela Andrzej J, Baumgartner Paul, Upadhyay Vikrant, Nimigean Crina M, Stahlberg Henning,
Project High-Resolution Membrane Protein Structures by Cryo-EM
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Original article (peer-reviewed)

Journal Structure (London, England : 1993)
Volume (Issue) 26(1)
Page(s) 20 - 27
Title of proceedings Structure (London, England : 1993)
DOI 10.1016/j.str.2017.11.012

Open Access

Type of Open Access Publisher (Gold Open Access)


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.