2DP3

Crystal structure of a double mutant (C202A/A198V) of Triosephosphate isomerase from giardia lamblia


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free: 0.181 
  • R-Value Work: 0.175 

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


Literature

Disulfide Bridges in the Mesophilic Triosephosphate Isomerase from Giardia lamblia Are Related to Oligomerization and Activity

Reyes-Vivas, H.Diaz, A.Peon, J.Mendoza-Hernandez, G.Hernandez-Alcantara, G.De la Mora-De la Mora, I.Enriquez-Flores, S.Dominguez-Ramirez, L.Lopez-Velazquez, G.

(2007) J Mol Biol 365: 752-763

  • DOI: https://doi.org/10.1016/j.jmb.2006.10.053
  • Primary Citation of Related Structures:  
    2DP3

  • PubMed Abstract: 

    Triosephosphate isomerase from the mesophile Giardia lamblia (GlTIM) is the only known TIM with natural disulfide bridges. We previously found that oxidized and reduced thiol states of GlTIM are involved in the interconversion between native dimers and higher oligomeric species, and in the regulation of enzymatic activity. Here, we found that trophozoites and cysts have different oligomeric species of GlTIM and complexes of GlTIM with other proteins. Our data indicate that the internal milieu of G. lamblia is favorable for the formation of disulfide bonds. Enzyme mutants of the three most solvent exposed Cys of GlTIM (C202A, C222A, and C228A) were prepared to ascertain their contribution to oligomerization and activity. The data show that the establishment of a disulfide bridge between two C202 of two dimeric GlTIMs accounts for multimerization. In addition, we found that the establishment of an intramonomeric disulfide bond between C222 and C228 abolishes catalysis. Multimerization and inactivation are both reversed by reducing conditions. The 3D structure of the C202A GlTIM was solved at 2.1 A resolution, showing that the environment of the C202 is prone to hydrophobic interactions. Molecular dynamics of an in silico model of GlTIM when the intramonomeric disulfide bond is formed, showed that S216 is displaced 4.6 A from its original position, causing loss of hydrogen bonds with residues of the active-site loop. This suggests that this change perturb the conformational state that aligns the catalytic center with the substrate, inducing enzyme inactivation.


  • Organizational Affiliation

    Laboratorio de Bioquimica Genetica, Instituto Nacional de Pediatria, 04530 Mexico, D.F.


Macromolecules
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Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Triosephosphate isomerase257Giardia intestinalisMutation(s): 2 
Gene Names: gltim
EC: 5.3.1.1 (PDB Primary Data), 4.2.3.3 (UniProt)
UniProt
Find proteins for P36186 (Giardia intestinalis)
Explore P36186 
Go to UniProtKB:  P36186
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP36186
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free: 0.181 
  • R-Value Work: 0.175 
  • Space Group: I 2 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 55.371α = 90
b = 100.443β = 90
c = 118.796γ = 90
Software Package:
Software NamePurpose
CrystalCleardata collection
MOSFLMdata reduction
CNSrefinement
CrystalCleardata reduction
CNSphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2007-01-02
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance
  • Version 1.3: 2021-11-10
    Changes: Database references, Derived calculations
  • Version 1.4: 2023-10-25
    Changes: Data collection, Refinement description