5M5J

Thioredoxin reductase from Giardia duodenalis


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.65 Å
  • R-Value Free: 0.260 
  • R-Value Work: 0.202 
  • R-Value Observed: 0.205 

Starting Model: experimental
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Ligand Structure Quality Assessment 


This is version 1.3 of the entry. See complete history


Literature

Structural characterization of Giardia duodenalis thioredoxin reductase (gTrxR) and computational analysis of its interaction with NBDHEX.

Brogi, S.Fiorillo, A.Chemi, G.Butini, S.Lalle, M.Ilari, A.Gemma, S.Campiani, G.

(2017) Eur J Med Chem 135: 479-490

  • DOI: https://doi.org/10.1016/j.ejmech.2017.04.057

  • PubMed Abstract: 

    Giardia duodenalis is a microaerophilic parasite that colonizes the upper portions of the small intestine of humans. Giardia infection is a major contributor to diarrheal disease worldwide. Nitroheterocycles (e.g. metronidazole) or benzimidazoles (e.g. albendazole) are the most commonly used therapeutic agents. Unfortunately, their efficacy is reduced by low compliance or resistance phenomena. We recently discovered that the antitumoral drug 6-(7-nitro-2,1,3-benzoxadiazol-4-ylthio)hexanol (NBDHEX) is active against G. duodenalis trophozoites and its mode of action is linked to inhibition of thioredoxin reductase (gTrxR), a key component of Giardia redox system: gTrxR provides efficient defenses against reactive oxygen species (ROS), it is a target of 5-nitroimidazoles antiparasitic drugs and also contributes to their metabolism. However, the exact mechanism responsible for the gTrxR inhibition mediated by this chemical class of antigiardial compounds is yet to be defined. The definition of the structural determinants of activity against gTrxR could be important for the identification of novel drugs endowed with an innovative mode of action. With this aim, we solved the crystal structure of gTrxR and we analyzed in silico the binding mode of NBDHEX. The data presented herein could guide the development of NBDHEX derivatives tailored for selective inhibition of gTrxR as antigiardial agents.


  • Organizational Affiliation

    European Research Centre for Drug Discovery and Development (NatSynDrugs), Department of Biotechnology, Chemistry, and Pharmacy, Università di Siena via Aldo Moro 2, 53100 Siena, Italy.


Macromolecules
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Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Thioredoxin reductase
A, B
325Giardia intestinalisMutation(s): 0 
Gene Names: GL50803_9827
EC: 1.8.1.9
UniProt
Find proteins for E2RU27 (Giardia intestinalis (strain ATCC 50803 / WB clone C6))
Explore E2RU27 
Go to UniProtKB:  E2RU27
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupE2RU27
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.65 Å
  • R-Value Free: 0.260 
  • R-Value Work: 0.202 
  • R-Value Observed: 0.205 
  • Space Group: P 41 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 85.643α = 90
b = 85.643β = 90
c = 163.221γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
XDSdata reduction
Aimlessdata scaling
MOLREPphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2017-05-17
    Type: Initial release
  • Version 1.1: 2017-05-24
    Changes: Database references
  • Version 1.2: 2024-01-17
    Changes: Data collection, Database references, Refinement description
  • Version 1.3: 2024-11-13
    Changes: Structure summary