3RQW

Crystal structure of acetylcholine bound to a prokaryotic pentameric ligand-gated ion channel, ELIC


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.91 Å
  • R-Value Free: 0.231 
  • R-Value Work: 0.206 
  • R-Value Observed: 0.207 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Structure of the pentameric ligand-gated ion channel ELIC cocrystallized with its competitive antagonist acetylcholine.

Pan, J.Chen, Q.Willenbring, D.Yoshida, K.Tillman, T.Kashlan, O.B.Cohen, A.Kong, X.P.Xu, Y.Tang, P.

(2012) Nat Commun 3: 714-714

  • DOI: 10.1038/ncomms1703
  • Primary Citation of Related Structures:  
    3RQU, 3RQW

  • PubMed Abstract: 
  • ELIC, the pentameric ligand-gated ion channel from Erwinia chrysanthemi, is a prototype for Cys-loop receptors. Here we show that acetylcholine is a competitive antagonist for ELIC. We determine the acetylcholine-ELIC cocrystal structure to a 2.9-Å r ...

    ELIC, the pentameric ligand-gated ion channel from Erwinia chrysanthemi, is a prototype for Cys-loop receptors. Here we show that acetylcholine is a competitive antagonist for ELIC. We determine the acetylcholine-ELIC cocrystal structure to a 2.9-Å resolution and find that acetylcholine binding to an aromatic cage at the subunit interface induces a significant contraction of loop C and other structural rearrangements in the extracellular domain. The side chain of the pore-lining residue F247 reorients and the pore size consequently enlarges, but the channel remains closed. We attribute the inability of acetylcholine to activate ELIC primarily to weak cation-π and electrostatic interactions in the pocket, because an acetylcholine derivative with a simple quaternary-to-tertiary ammonium substitution activates the channel. This study presents a compelling case for understanding the structural underpinning of the functional relationship between agonism and competitive antagonism in the Cys-loop receptors, providing a new framework for developing novel therapeutic drugs.


    Organizational Affiliation

    Department of Anesthesiology, 2057 Biomedical Science Tower 3, 3501 Fifth Avenue, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15260, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
ELIC Pentameric Ligand Gated Ion Channel from Erwinia ChrysanthemiABCDEFGHIJ322Dickeya dadantii 3937Mutation(s): 0 
Gene Names: Dda3937_00520
Membrane protein
Mpstruc
Group: 
TRANSMEMBRANE PROTEINS: ALPHA-HELICAL
Sub Group: 
Cys-Loop Receptor Family
Protein: 
Prokaryotic pentameric ligand-gated ion channel (ELIC) in complex with acetylcholine
Find proteins for E0SJQ4 (Dickeya dadantii (strain 3937))
Explore E0SJQ4 
Go to UniProtKB:  E0SJQ4
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MES
Query on MES

Download CCD File 
A, B, D, E, F, G, I, J
2-(N-MORPHOLINO)-ETHANESULFONIC ACID
C6 H13 N O4 S
SXGZJKUKBWWHRA-UHFFFAOYSA-N
 Ligand Interaction
ACH
Query on ACH

Download CCD File 
A, B, C, D, E, F, G, H, I, J
ACETYLCHOLINE
C7 H16 N O2
OIPILFWXSMYKGL-UHFFFAOYSA-N
 Ligand Interaction
GOL
Query on GOL

Download CCD File 
A, B, C, D, E, F, G, H, I, J
GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
ACHKd :  2000000   nM  PDBBind
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.91 Å
  • R-Value Free: 0.231 
  • R-Value Work: 0.206 
  • R-Value Observed: 0.207 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 105.763α = 90
b = 266.068β = 107.82
c = 111.162γ = 90
Software Package:
Software NamePurpose
SSRLdata collection
PHENIXmodel building
PHENIXrefinement
XDSdata reduction
SCALAdata scaling
PHENIXphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2012-03-07
    Type: Initial release
  • Version 1.1: 2012-03-14
    Changes: Database references, Other, Structure summary
  • Version 1.2: 2012-03-28
    Changes: Database references