3IGQ

Crystal structure of the extracellular domain of a bacterial pentameric ligand-gated ion channel


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.255 
  • R-Value Work: 0.207 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal structure of the extracellular domain of a bacterial ligand-gated ion channel

Nury, H.Bocquet, N.Le Poupon, C.Raynal, B.Haouz, A.Corringer, P.-J.Delarue, M.

(2010) J.Mol.Biol. 395: 1114-1127

  • DOI: 10.1016/j.jmb.2009.11.024

  • PubMed Abstract: 
  • The crystal structure of the extracellular domain (ECD) of the pentameric ligand-gated ion-channel from Gloeobacter violaceus (GLIC) was solved at neutral pH at 2.3 A resolution in two crystal forms, showing a surprising hexameric quaternary structur ...

    The crystal structure of the extracellular domain (ECD) of the pentameric ligand-gated ion-channel from Gloeobacter violaceus (GLIC) was solved at neutral pH at 2.3 A resolution in two crystal forms, showing a surprising hexameric quaternary structure with a 6-fold axis replacing the expected 5-fold axis. While each subunit retains the usual beta-sandwich immunoglobulin-like fold, small deviations from the whole GLIC structure indicate zones of differential flexibility. The changes in interface between two adjacent subunits in the pentamer and the hexamer can be described in a downward translation by one inter-strand distance and a global rotation of the second subunit, using the first one for superposition. While global characteristics of the interface, such as the buried accessible surface area, do not change very much, most of the atom-atom interactions are rearranged. It thus appears that the transmembrane domain is necessary for the proper oligomeric assembly of GLIC and that there is an intrinsic plasticity or polymorphism in possible subunit-subunit interfaces at the ECD level, the latter behaving as a monomer in solution. Possible functional implications of these novel structural data are discussed in the context of the allosteric transition of this family of proteins. In addition, we propose a novel way to quantify elastic energy stored in the interface between subunits, which indicates a tenser interface for the open form than for the closed form (rest state). The hexameric or pentameric forms of the ECD have a similar negative curvature in their subunit-subunit interface, while acetylcholine binding proteins have a smaller and positive curvature that increases from the apo to the holo form.


    Organizational Affiliation

    Institut Pasteur, Unité de Dynamique Structurale des Macromolécules, CNRS URA 2185, Institut Pasteur, 25 rue du Dr Roux, 75015 Paris, France.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Glr4197 protein
A, B, C, D, E, F
201Gloeobacter violaceus (strain PCC 7421)Mutation(s): 4 
Gene Names: glvI
Membrane protein
mpstruct
Group: 
TRANSMEMBRANE PROTEINS: ALPHA-HELICAL
Sub Group: 
Cys-Loop Receptor Family
Protein: 
Prokaryotic pentameric ligand-gated ion channel (GLIC)
Find proteins for Q7NDN8 (Gloeobacter violaceus (strain PCC 7421))
Go to UniProtKB:  Q7NDN8
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NA
Query on NA

Download SDF File 
Download CCD File 
A, B, C, D, E, F
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
CL
Query on CL

Download SDF File 
Download CCD File 
A, B, C, D, E, F
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
ACY
Query on ACY

Download SDF File 
Download CCD File 
A, B, C, D, E, F
ACETIC ACID
C2 H4 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-N
 Ligand Interaction
HG
Query on HG

Download SDF File 
Download CCD File 
A, B, C, D, E, F
MERCURY (II) ION
Hg
BQPIGGFYSBELGY-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.255 
  • R-Value Work: 0.207 
  • Space Group: P 21 21 2
Unit Cell:
Length (Å)Angle (°)
a = 84.450α = 90.00
b = 130.240β = 90.00
c = 113.590γ = 90.00
Software Package:
Software NamePurpose
SCALAdata scaling
SHARPphasing
XDSdata reduction
REFMACrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 2009-07-28 
  • Released Date: 2009-12-08 
  • Deposition Author(s): Nury, H., Delarue, M.

Revision History 

  • Version 1.0: 2009-12-08
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance
  • Version 1.2: 2014-02-05
    Type: Database references