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

Overview

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.

publication date

  • December 14, 2017

Research

keywords

  • Bacterial Proteins
  • Cyclic AMP
  • Lipid Bilayers
  • Mesorhizobium
  • Potassium
  • Potassium Channels, Voltage-Gated

Identity

Scopus Document Identifier

  • 85039040747

Digital Object Identifier (DOI)

  • 10.1016/j.str.2017.11.012

PubMed ID

  • 29249605

Additional Document Info

volume

  • 26

issue

  • 1