3RQU

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


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.09 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.209 
  • R-Value Observed: 0.211 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


This is version 1.3 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: https://doi.org/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 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)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
ELIC Pentameric Ligand Gated Ion Channel from Erwinia Chrysanthemi
A, B, C, D, E
A, B, C, D, E, F, G, H, I, J
322Dickeya dadantii 3937Mutation(s): 0 
Gene Names: Dda3937_00520
Membrane Entity: Yes 
UniProt
Find proteins for E0SJQ4 (Dickeya dadantii (strain 3937))
Explore E0SJQ4 
Go to UniProtKB:  E0SJQ4
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupE0SJQ4
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
MES
Query on MES

Download Ideal Coordinates CCD File 
BA [auth G]
CA [auth G]
FA [auth I]
K [auth A]
M [auth B]
BA [auth G],
CA [auth G],
FA [auth I],
K [auth A],
M [auth B],
S [auth C],
U [auth D]
2-(N-MORPHOLINO)-ETHANESULFONIC ACID
C6 H13 N O4 S
SXGZJKUKBWWHRA-UHFFFAOYSA-N
GOL
Query on GOL

Download Ideal Coordinates CCD File 
AA [auth F]
DA [auth G]
EA [auth H]
GA [auth I]
HA [auth I]
AA [auth F],
DA [auth G],
EA [auth H],
GA [auth I],
HA [auth I],
IA [auth I],
JA [auth J],
KA [auth J],
L [auth A],
LA [auth J],
N [auth B],
O [auth B],
P [auth B],
Q [auth B],
R [auth B],
T [auth C],
V [auth D],
W [auth D],
X [auth D],
Y [auth E],
Z [auth E]
GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.09 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.209 
  • R-Value Observed: 0.211 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 105.289α = 90
b = 266.97β = 107.53
c = 111.074γ = 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  (Full details and data files)

  • 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
  • Version 1.3: 2023-09-13
    Changes: Data collection, Database references, Derived calculations, Refinement description