3FZ0

Inosine-Guanosine Nucleoside Hydrolase (IG-NH)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.224 
  • R-Value Work: 0.189 
  • R-Value Observed: 0.191 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Structure and mechanism of the 6-oxopurine nucleosidase from Trypanosoma brucei brucei

Vandemeulebroucke, A.Minici, C.Bruno, I.Muzzolini, L.Tornaghi, P.Parkin, D.W.Versees, W.Steyaert, J.Degano, M.

(2010) Biochemistry 49: 8999-9010

  • DOI: 10.1021/bi100697d
  • Primary Citation of Related Structures:  
    3FZ0

  • PubMed Abstract: 
  • Trypanosomes are purine-auxotrophic parasites that depend upon nucleoside hydrolase (NH) activity to salvage nitrogenous bases necessary for nucleic acid and cofactor synthesis. Nonspecific and purine-specific NHs have been widely studied, yet little is known about the 6-oxopurine-specific isozymes, although they are thought to play a primary role in the catabolism of exogenously derived nucleosides ...

    Trypanosomes are purine-auxotrophic parasites that depend upon nucleoside hydrolase (NH) activity to salvage nitrogenous bases necessary for nucleic acid and cofactor synthesis. Nonspecific and purine-specific NHs have been widely studied, yet little is known about the 6-oxopurine-specific isozymes, although they are thought to play a primary role in the catabolism of exogenously derived nucleosides. Here, we report the first functional and structural characterization of the inosine-guanosine-specific NH from Trypanosoma brucei brucei. The enzyme shows near diffusion-limited efficiency coupled with a clear specificity for 6-oxopurine nucleosides achieved through a catalytic selection of these substrates. Pre-steady-state kinetic analysis reveals ordered product release, and a rate-limiting structural rearrangement that is associated with the release of the product, ribose. The crystal structure of this trypanosomal NH determined to 2.5 Å resolution reveals distinctive features compared to those of both purine- and pyrimidine-specific isozymes in the framework of the conserved and versatile NH fold. Nanomolar iminoribitol-based inhibitors identified in this study represent important lead compounds for the development of novel therapeutic strategies against trypanosomal diseases.


    Related Citations: 
    • Guanosine-inosine-preferring nucleoside N-glycohydrolase from Crithidia fasciculata
      Estupinan, B., Schramm, V.L.
      (1994) J Biol Chem 269: 23068

    Organizational Affiliation

    Department of Molecular and Cellular Interactions and Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Nucleoside hydrolase, putativeA, B, C, D360Trypanosoma bruceiMutation(s): 2 
Gene Names: Tb927.7.4570
EC: 3.2.2.1
Find proteins for Q57X73 (Trypanosoma brucei brucei (strain 927/4 GUTat10.1))
Explore Q57X73 
Go to UniProtKB:  Q57X73
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.224 
  • R-Value Work: 0.189 
  • R-Value Observed: 0.191 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 124.69α = 90
b = 116.04β = 90
c = 204.76γ = 90
Software Package:
Software NamePurpose
DNAdata collection
MOLREPphasing
REFMACrefinement
XDSdata reduction
SCALAdata scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2010-01-26
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Advisory, Version format compliance