2AAW

Studies on ligand binding and enzyme inhibition of Plasmodium falciparum glutathione S-transferase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.40 Å
  • R-Value Free: 0.237 
  • R-Value Work: 0.194 
  • R-Value Observed: 0.194 

Starting Model: experimental
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This is version 1.4 of the entry. See complete history


Literature

Plasmodium falciparum glutathione S-transferase--structural and mechanistic studies on ligand binding and enzyme inhibition.

Hiller, N.Fritz-Wolf, K.Deponte, M.Wende, W.Zimmermann, H.Becker, K.

(2006) Protein Sci 15: 281-289

  • DOI: https://doi.org/10.1110/ps.051891106
  • Primary Citation of Related Structures:  
    2AAW

  • PubMed Abstract: 

    Glutathione S-transferase of the malarial parasite Plasmodium falciparum (PfGST) represents a novel class of GST isoenzymes. Since the architecture of the PfGST substrate binding site differs significantly from its human counterparts and there is only this one isoenzyme present in the parasite, PfGST is considered a highly attractive target for antimalarial drug development. Here we report the mechanistic, kinetic, and structural characterization of PfGST as well as its interaction with different ligands. Our data indicate that in solution PfGST is present as a tetramer that dissociates into dimers in the presence of glutathione (GSH). Fluorescence spectroscopy shows that in the presence of GSH GST serves as ligandin for parasitotoxic ferriprotoporphyrin IX with a high- and a low-affinity binding site. This is supported by a clear uncompetitive inhibition type. Site-directed mutagenesis studies demonstrate that neither Cys 86 nor Cys 101 contribute to the peroxidase activity of the enzyme, which is thus performed GSH-dependently at the active site. Tyr 9 is responsible for the deprotonation of GSH and Lys 15, but also Gln 71 are involved in GSH binding. We furthermore report the 2.4 A resolution X-ray structure of PfGST cocrystallized with the inhibitor S-hexylglutathione. In comparison with a previously reported structure obtained by crystal soaking, differences occur at the C-terminal end of helix alpha4 and at the S-hexylmoiety of the inhibitor. We furthermore show that, in contrast to previous reports, the antimalarial drug artemisinin is not metabolized by PfGST.


  • Organizational Affiliation

    Interdisciplinary Research Center, Justus-Liebig-University, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
glutathione s-transferaseA,
B [auth C]
222Plasmodium falciparumMutation(s): 0 
EC: 2.5.1.18
UniProt
Find proteins for Q8ILQ7 (Plasmodium falciparum (isolate 3D7))
Explore Q8ILQ7 
Go to UniProtKB:  Q8ILQ7
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ8ILQ7
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.40 Å
  • R-Value Free: 0.237 
  • R-Value Work: 0.194 
  • R-Value Observed: 0.194 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 61.17α = 90
b = 69.99β = 90
c = 123.69γ = 90
Software Package:
Software NamePurpose
CNSrefinement
CAD4data reduction
XDSdata scaling
CNSphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2006-01-10
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2015-06-10
    Changes: Non-polymer description
  • Version 1.4: 2023-08-23
    Changes: Data collection, Database references, Derived calculations, Refinement description, Structure summary