2J3Q

Torpedo acetylcholinesterase complexed with fluorophore thioflavin T


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.257 
  • R-Value Work: 0.199 
  • R-Value Observed: 0.199 

wwPDB Validation 3D Report Full Report



Literature

Crystal structure of thioflavin T bound to the peripheral site of Torpedo californica acetylcholinesterase reveals how thioflavin T acts as a sensitive fluorescent reporter of ligand binding to the acylation site.

Harel, M.Sonoda, L.K.Silman, I.Sussman, J.L.Rosenberry, T.L.

(2008) J Am Chem Soc 130: 7856-7861

  • DOI: 10.1021/ja7109822
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • Acetylcholinesterase plays a key role in cholinergic synaptic transmission by hydrolyzing the neurotransmitter acetylcholine with one of the highest known catalytic rate constants. Hydrolysis occurs in a narrow and deep gorge that contains two sites ...

    Acetylcholinesterase plays a key role in cholinergic synaptic transmission by hydrolyzing the neurotransmitter acetylcholine with one of the highest known catalytic rate constants. Hydrolysis occurs in a narrow and deep gorge that contains two sites of ligand binding: A peripheral site, or P-site, near the gorge entrance that contributes to catalytic efficiency both by transiently trapping substrate molecules as they enter the gorge and by allosterically accelerating the transfer of the substrate acyl group to a serine hydroxyl in an acylation site or A-site at the base of the gorge. Thioflavin T is a useful reporter of ligand interactions with the A-site. It binds specifically to the P-site with fluorescence that is enhanced approximately 1000-fold over that of unbound thioflavin T, and the enhanced fluorescence is quenched 1.5- to 4-fold when another ligand binds to the A-site in a ternary complex. To clarify the structural basis of this advantageous signal change, we here report the X-ray structure of the complex of thioflavin T with Torpedo californica acetylcholinesterase. The two aromatic rings in thioflavin T are coplanar and are packed snugly parallel to the aromatic side chains of Trp279, Tyr334, and Phe330. Overlays of this structure with the crystal structures of Torpedo californica acetylcholinesterase complexes with either edrophonium or m-( N, N, N-trimethylammonio)-2,2,2-trifluoroacetophenone, two small aromatic ligands that bind specifically to the A-site, indicate that the phenyl side chain of Phe330 must rotate to sterically accommodate both thioflavin T and the A-site ligand in the ternary complex. This rotation may allow some relaxation of the strict coplanarity of the aromatic rings in the bound thioflavin T and result in partial quenching of its fluorescence.


    Organizational Affiliation

    Department of Structural Biology, Weizmann Institute of Science, Rehovot 76100, Israel.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
ACETYLCHOLINESTERASE
A
543Tetronarce californicaMutation(s): 0 
Gene Names: ache
EC: 3.1.1.7
Find proteins for P04058 (Tetronarce californica)
Go to UniProtKB:  P04058
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
TFL
Query on TFL

Download CCD File 
A
2-[4-(DIMETHYLAMINO)PHENYL]-6-HYDROXY-3-METHYL-1,3-BENZOTHIAZOL-3-IUM
C16 H17 N2 O S
NOVJJPLRUMZSDK-UHFFFAOYSA-O
 Ligand Interaction
NAG
Query on NAG

Download CCD File 
A
N-ACETYL-D-GLUCOSAMINE
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
MG
Query on MG

Download CCD File 
A
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.257 
  • R-Value Work: 0.199 
  • R-Value Observed: 0.199 
  • Space Group: P 32 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 139.44α = 90
b = 139.44β = 90
c = 71.42γ = 120
Software Package:
Software NamePurpose
CNSrefinement
XDSdata reduction
XSCALEdata scaling
CNSphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-09-04
    Type: Initial release
  • Version 1.1: 2011-05-08
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 2.0: 2018-07-25
    Changes: Advisory, Atomic model, Data collection, Database references, Derived calculations, Non-polymer description, Structure summary