2WNC

Crystal structure of Aplysia ACHBP in complex with tropisetron


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.212 
  • R-Value Work: 0.177 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structural Determinants for Interaction of Partial Agonists with Acetylcholine Binding Protein and Neuronal Alpha7 Nicotinic Acetylcholine Receptor.

Hibbs, R.E.Sulzenbacher, G.Shi, J.Talley, T.T.Conrod, S.Kem, W.R.Taylor, P.Marchot, P.Bourne, Y.

(2009) Embo J. 28: 3040

  • DOI: 10.1038/emboj.2009.227
  • Primary Citation of Related Structures:  2WN9, 2WNJ, 2WNL

  • PubMed Abstract: 
  • The pentameric acetylcholine-binding protein (AChBP) is a soluble surrogate of the ligand binding domain of nicotinic acetylcholine receptors. Agonists bind within a nest of aromatic side chains contributed by loops C and F on opposing faces of each ...

    The pentameric acetylcholine-binding protein (AChBP) is a soluble surrogate of the ligand binding domain of nicotinic acetylcholine receptors. Agonists bind within a nest of aromatic side chains contributed by loops C and F on opposing faces of each subunit interface. Crystal structures of Aplysia AChBP bound with the agonist anabaseine, two partial agonists selectively activating the alpha7 receptor, 3-(2,4-dimethoxybenzylidene)-anabaseine and its 4-hydroxy metabolite, and an indole-containing partial agonist, tropisetron, were solved at 2.7-1.75 A resolution. All structures identify the Trp 147 carbonyl oxygen as the hydrogen bond acceptor for the agonist-protonated nitrogen. In the partial agonist complexes, the benzylidene and indole substituent positions, dictated by tight interactions with loop F, preclude loop C from adopting the closed conformation seen for full agonists. Fluctuation in loop C position and duality in ligand binding orientations suggest molecular bases for partial agonism at full-length receptors. This study, while pointing to loop F as a major determinant of receptor subtype selectivity, also identifies a new template region for designing alpha7-selective partial agonists to treat cognitive deficits in mental and neurodegenerative disorders.


    Organizational Affiliation

    Department of Pharmacology, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
SOLUBLE ACETYLCHOLINE RECEPTOR
A, B, C, D, E
227Aplysia californicaN/A
Find proteins for Q8WSF8 (Aplysia californica)
Go to UniProtKB:  Q8WSF8
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
TKT
Query on TKT

Download SDF File 
Download CCD File 
A, B, C, D, E
(3-ENDO)-8-METHYL-8-AZABICYCLO[3.2.1]OCT-3-YL 1H-INDOLE-3-CARBOXYLATE
TROPISETRON
C17 H20 N2 O2
ZNRGQMMCGHDTEI-ITGUQSILSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
TKTKd: 479 nM BINDINGMOAD
TKTKd: 479 nM PDBBIND
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.212 
  • R-Value Work: 0.177 
  • Space Group: I 2 3
Unit Cell:
Length (Å)Angle (°)
a = 212.584α = 90.00
b = 212.584β = 90.00
c = 212.584γ = 90.00
Software Package:
Software NamePurpose
SCALAdata scaling
REFMACrefinement
MOSFLMdata reduction
AMoREphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2009-09-01
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Refinement description, Version format compliance