The purine nucleoside phosphorylase from Trichomonas vaginalis is a homologue of the bacterial enzyme.

@article{Munagala2002ThePN,
  title={The purine nucleoside phosphorylase from Trichomonas vaginalis is a homologue of the bacterial enzyme.},
  author={Narsimha R. Munagala and Ching C. Wang},
  journal={Biochemistry},
  year={2002},
  volume={41 33},
  pages={
          10382-9
        }
}
Trichomonas vaginalis is a parasitic protozoan and the causative agent of trichomoniasis. Its primary purine salvage system, consisting of a purine nucleoside phosphorylase (PNP) and a purine nucleoside kinase, presents potential targets for designing selective inhibitors as antitrichomonial drugs because of lack of de novo synthesis of purine nucleotides in this organism. cDNA encoding T. vaginalis PNP was isolated by complementation of an Escherichia coli strain deficient in PNP and expressed… 
Adenosine is the primary precursor of all purine nucleotides in Trichomonas vaginalis.
Identification of a Subversive Substrate of Trichomonas vaginalis Purine Nucleoside Phosphorylase and the Crystal Structure of the Enzyme-Substrate Complex*
TLDR
It is discovered that the nontoxic nucleoside analogue 2-fluoro-2′-deoxyadenosine (F-dAdo) is a “subversive substrate” for T. vaginalis PNP, and the structures of the TvPNP complexes suggest opportunities for further improved subversive substrates beyond F- dAdo.
Inhibition and structure of Trichomonas vaginalis purine nucleoside phosphorylase with picomolar transition state analogues.
TLDR
Trichomonas vaginalis PNP (TvPNP) functions in the reverse direction relative to the PNPs in other organisms, and ImmA and DADMe-ImmA are weak inhibitors of human and P. falciparum PnPs.
Identification and characterization of a novel gene of grouper iridovirus encoding a purine nucleoside phosphorylase.
TLDR
This is the first report of a viral PNP with enzymic activity reported and the recombinant GIV PNP protein was shown to catalyse the reversible phosphorolysis of purine nucleosides and could accept guanosine, inosine and adenosine as substrates.
Characterization of the adenine nucleoside specific phosphorylase of Bacillus cereus.
Comprehensive characterization of purine and pyrimidine transport activities in Trichomonas vaginalis and functional cloning of a trichomonad nucleoside transporter
TLDR
The in‐depth characterization of purine and pyrimidine transporters provides a critical foundation for the development of new anti‐trichomonal nucleoside analogues.
Structural Determinants of the 5′-Methylthioinosine Specificity of Plasmodium Purine Nucleoside Phosphorylase
TLDR
Structural features in Plasmodium falciparum purine nucleoside phosphorylase (PfPNP) that affect efficiency of catalysis as well as those that make it suitable for dual specificity are explored.
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