5HEG

Pentameric ligand-gated ion channel GLIC mutant P246G


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.214 Å
  • R-Value Free: 0.258 
  • R-Value Work: 0.247 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Signal Transduction at the Domain Interface of Prokaryotic Pentameric Ligand-Gated Ion Channels.

Bertozzi, C.Zimmermann, I.Engeler, S.Hilf, R.J.Dutzler, R.

(2016) Plos Biol. 14: e1002393-e1002393

  • DOI: 10.1371/journal.pbio.1002393
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Pentameric ligand-gated ion channels are activated by the binding of agonists to a site distant from the ion conduction path. These membrane proteins consist of distinct ligand-binding and pore domains that interact via an extended interface. Here, w ...

    Pentameric ligand-gated ion channels are activated by the binding of agonists to a site distant from the ion conduction path. These membrane proteins consist of distinct ligand-binding and pore domains that interact via an extended interface. Here, we have investigated the role of residues at this interface for channel activation to define critical interactions that couple conformational changes between the two structural units. By characterizing point mutants of the prokaryotic channels ELIC and GLIC by electrophysiology, X-ray crystallography and isothermal titration calorimetry, we have identified conserved residues that, upon mutation, apparently prevent activation but not ligand binding. The positions of nonactivating mutants cluster at a loop within the extracellular domain connecting β-strands 6 and 7 and at a loop joining the pore-forming helix M2 with M3 where they contribute to a densely packed core of the protein. An ionic interaction in the extracellular domain between the turn connecting β-strands 1 and 2 and a residue at the end of β-strand 10 stabilizes a state of the receptor with high affinity for agonists, whereas contacts of this turn to a conserved proline residue in the M2-M3 loop appear to be less important than previously anticipated. When mapping residues with strong functional phenotype on different channel structures, mutual distances are closer in conducting than in nonconducting conformations, consistent with a potential role of contacts in the stabilization of the open state. Our study has revealed a pattern of interactions that are crucial for the relay of conformational changes from the extracellular domain to the pore region of prokaryotic pentameric ligand-gated ion channels. Due to the strong conservation of the interface, these results are relevant for the entire family.


    Organizational Affiliation

    Department of Biochemistry, University of Zürich, Zürich, Switzerland.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Proton-gated ion channel
A, B, C, D, E
316Gloeobacter violaceus (strain PCC 7421)Mutation(s): 1 
Gene Names: glvI
Find proteins for Q7NDN8 (Gloeobacter violaceus (strain PCC 7421))
Go to UniProtKB:  Q7NDN8
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.214 Å
  • R-Value Free: 0.258 
  • R-Value Work: 0.247 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 180.380α = 90.00
b = 134.210β = 101.97
c = 160.790γ = 90.00
Software Package:
Software NamePurpose
XDSdata reduction
XDSdata scaling
PHASERphasing
PHENIXrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Swiss National Science FoundationSwitzerland--

Revision History 

  • Version 1.0: 2016-03-02
    Type: Initial release
  • Version 1.1: 2016-03-16
    Type: Database references
  • Version 1.2: 2017-09-06
    Type: Author supporting evidence