PDBsum entry 4chv

Transport

PDB id: 4chv

Contents

Protein chains

344 a.a.

Metals

__K ×2

PDB id:

4chv

Name:

Transport

Title:

The electron crystallography structure of the camp-bound potassium channel mlok1

Structure:

Cyclic nucleotide-gated potassium channel mll3241. Chain: a, b, c, d. Synonym: mlotik1 channel. Engineered: yes. Other_details: camp present in buffer

Source:

Mesorhizobium loti. Organism_taxid: 381. Expressed in: escherichia coli. Expression_system_taxid: 469008.

Authors:

J.Kowal,M.Chami,P.Baumgartner,M.Arheit,P.L.Chiu,M.Rangl,S.Scheuring, G.F.Schroeder,C.M.Nimigean,H.Stahlberg

Key ref:

J.Kowal et al. (2014). Ligand-induced structural changes in the cyclic nucleotide-modulated potassium channel MloK1. Nat Commun, 5, 3106. PubMed id: 24469021 DOI: 10.1038/ncomms4106

Date:

04-Dec-13 Release date: 15-Jan-14

Protein chains

Q98GN8  (CNGK1_RHILO) -  Cyclic nucleotide-gated potassium channel mll3241 from Mesorhizobium japonicum (strain LMG 29417 / CECT 9101 / MAFF 303099)

Seq: 355 a.a.

Struc: 344 a.a.

DOI no: 10.1038/ncomms4106

Nat Commun 5:3106 (2014)

PubMed id: 24469021

Ligand-induced structural changes in the cyclic nucleotide-modulated potassium channel MloK1.

J.Kowal, M.Chami, P.Baumgartner, M.Arheit, P.L.Chiu, M.Rangl, S.Scheuring, G.F.Schröder, C.M.Nimigean, H.Stahlberg.

ABSTRACT

Cyclic nucleotide-modulated ion channels are important for signal transduction and pacemaking in eukaryotes. The molecular determinants of ligand gating in these channels are still unknown, mainly because of a lack of direct structural information. Here we report ligand-induced conformational changes in full-length MloK1, a cyclic nucleotide-modulated potassium channel from the bacterium Mesorhizobium loti, analysed by electron crystallography and atomic force microscopy. Upon cAMP binding, the cyclic nucleotide-binding domains move vertically towards the membrane, and directly contact the S1-S4 voltage sensor domains. This is accompanied by a significant shift and tilt of the voltage sensor domain helices. In both states, the inner pore-lining helices are in an 'open' conformation. We propose a mechanism in which ligand binding can favour pore opening via a direct interaction between the cyclic nucleotide-binding domains and voltage sensors. This offers a simple mechanistic hypothesis for the coupling between ligand gating and voltage sensing in eukaryotic HCN channels.