4NPQ

The resting-state conformation of the GLIC ligand-gated ion channel


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 4.35 Å
  • R-Value Free: 0.244 
  • R-Value Work: 0.240 
  • R-Value Observed: 0.240 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Crystal structures of a pentameric ligand-gated ion channel provide a mechanism for activation.

Sauguet, L.Shahsavar, A.Poitevin, F.Huon, C.Menny, A.Nemecz, A.Haouz, A.Changeux, J.P.Corringer, P.J.Delarue, M.

(2014) Proc Natl Acad Sci U S A 111: 966-971

  • DOI: 10.1073/pnas.1314997111
  • Primary Citation of Related Structures:  
    4NPP, 4NPQ

  • PubMed Abstract: 
  • Pentameric ligand-gated ion channels mediate fast chemical transmission of nerve signals. The structure of a bacterial proton-gated homolog has been established in its open and locally closed conformations at acidic pH. Here we report its crystal structure at neutral pH, thereby providing the X-ray structures of the two end-points of the gating mechanism in the same pentameric ligand-gated ion channel ...

    Pentameric ligand-gated ion channels mediate fast chemical transmission of nerve signals. The structure of a bacterial proton-gated homolog has been established in its open and locally closed conformations at acidic pH. Here we report its crystal structure at neutral pH, thereby providing the X-ray structures of the two end-points of the gating mechanism in the same pentameric ligand-gated ion channel. The large structural variability in the neutral pH structure observed in the four copies of the pentamer present in the asymmetric unit has been used to analyze the intrinsic fluctuations in this state, which are found to prefigure the transition to the open state. In the extracellular domain (ECD), a marked quaternary change is observed, involving both a twist and a blooming motion, and the pore in the transmembrane domain (TMD) is closed by an upper bend of helix M2 (as in locally closed form) and a kink of helix M1, both helices no longer interacting across adjacent subunits. On the tertiary level, detachment of inner and outer β sheets in the ECD reshapes two essential cavities at the ECD-ECD and ECD-TMD interfaces. The first one is the ligand-binding cavity; the other is close to a known divalent cation binding site in other pentameric ligand-gated ion channels. In addition, a different crystal form reveals that the locally closed and open conformations coexist as discrete ones at acidic pH. These structural results, together with site-directed mutagenesis, physiological recordings, and coarse-grained modeling, have been integrated to propose a model of the gating transition pathway.


    Organizational Affiliation

    Unité de Dynamique Structurale des Macromolécules, Unité Mixte de Recherche (UMR) 3528 du Centre National de la Recherche Scientifique (CNRS), Institut Pasteur, 75015 Paris, France.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Proton-gated ion channel
A, B, C, D, E, F, G, H
A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T
318Gloeobacter violaceus PCC 7421Mutation(s): 0 
Gene Names: glvIglr4197
Membrane Entity: Yes 
UniProt
Find proteins for Q7NDN8 (Gloeobacter violaceus (strain ATCC 29082 / PCC 7421))
Explore Q7NDN8 
Go to UniProtKB:  Q7NDN8
Protein Feature View
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 4.35 Å
  • R-Value Free: 0.244 
  • R-Value Work: 0.240 
  • R-Value Observed: 0.240 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 131.533α = 90
b = 384.095β = 98.47
c = 148.439γ = 90
Software Package:
Software NamePurpose
EDNAdata collection
PHASERphasing
BUSTERrefinement
XDSdata reduction
SCALAdata scaling

Structure Validation

View Full Validation Report




Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2013-12-25
    Type: Initial release
  • Version 1.1: 2014-02-05
    Changes: Database references
  • Version 1.2: 2018-01-24
    Changes: Structure summary