2V6U

High resolution crystal structure of pterin-4a-carbinolamine dehydratase from Toxoplasma gondii


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.60 Å
  • R-Value Free: 0.194 
  • R-Value Work: 0.172 
  • R-Value Observed: 0.173 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Crystal Structures of Toxoplasma Gondii Pterin-4A-Carbinolamine Dehydratase and Comparisons with Mammalian and Parasite Orthologues.

Cameron, S.Fyffe, S.A.Goldie, S.P.Hunter, W.N.

(2008) Mol Biochem Parasitol 158: 131

  • DOI: 10.1016/j.molbiopara.2007.12.002
  • Primary Citation of Related Structures:  
    2V6S, 2V6T, 2V6U

  • PubMed Abstract: 
  • The enzyme pterin-4a-carbinolamine dehydratase (PCD) is important for the recycling of pterins within eukaryotic cells. A recombinant expression system for PCD from the apicomplexan parasite Toxoplasma gondii has been prepared, the protein purified and crystallised ...

    The enzyme pterin-4a-carbinolamine dehydratase (PCD) is important for the recycling of pterins within eukaryotic cells. A recombinant expression system for PCD from the apicomplexan parasite Toxoplasma gondii has been prepared, the protein purified and crystallised. Single crystal X-ray diffraction methods have produced a high-resolution structure (1.6A) of the apo-enzyme and a low-resolution structure (3.1A) of a complex with a substrate-like ligand dihydrobiopterin (BH(2)). Analysis of the hydrogen bonding interactions that contribute to binding BH(2) suggest that the ligand is present in an enol tautomeric state, which makes it more similar to the physiological substrate. The enzyme can process (R)- and (S)-forms of pterin-4a-carbinolamine and the ligand complex suggests that His61 and His79 are placed to act independently as general bases for catalysis of the individual enantiomers. Comparisons with orthologues from other protozoan parasites (Plasmodium falciparum and Leishmania major) and with rat PCD, for which the structure is known, indicate a high degree of sequence and structure conservation of this enzyme. The molecular determinants of ligand recognition and PCD reactivity are therefore highly conserved across species.


    Organizational Affiliation

    Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
PTERIN-4A-CARBINOLAMINE DEHYDRATASEA, B104Toxoplasma gondii RHMutation(s): 0 
EC: 4.2.1.96
Find proteins for Q2Q449 (Toxoplasma gondii)
Explore Q2Q449 
Go to UniProtKB:  Q2Q449
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NA
Query on NA

Download Ideal Coordinates CCD File 
C [auth A]SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.60 Å
  • R-Value Free: 0.194 
  • R-Value Work: 0.172 
  • R-Value Observed: 0.173 
  • Space Group: P 43 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 120.135α = 90
b = 120.135β = 90
c = 49.773γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
MOSFLMdata reduction
SCALAdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2008-07-22
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Advisory, Version format compliance