Crystal structure of pteridine reductase 1 (PTR1) from Trypanosoma brucei in ternary complex with cofactor and inhibitor

Experimental Data Snapshot

  • Resolution: 1.85 Å
  • R-Value Free: 0.230 
  • R-Value Work: 0.184 
  • R-Value Observed: 0.186 

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Structure-Based Design and Synthesis of Antiparasitic Pyrrolopyrimidines Targeting Pteridine Reductase 1.

Khalaf, A.I.Huggan, J.K.Suckling, C.J.Gibson, C.L.Stewart, K.Giordani, F.Barrett, M.P.Wong, P.E.Barrack, K.L.Hunter, W.N.

(2014) J Med Chem 57: 6479

  • DOI: https://doi.org/10.1021/jm500483b
  • Primary Citation of Related Structures:  
    4CL8, 4CLD, 4CLE, 4CLH, 4CLO, 4CLR, 4CLX, 4CM1, 4CM3, 4CM4, 4CM5, 4CM6, 4CM7, 4CM8, 4CM9, 4CMA, 4CMB, 4CMC, 4CME, 4CMG, 4CMI, 4CMJ, 4CMK

  • PubMed Abstract: 

    The treatment of Human African trypanosomiasis remains a major unmet health need in sub-Saharan Africa. Approaches involving new molecular targets are important; pteridine reductase 1 (PTR1), an enzyme that reduces dihydrobiopterin in Trypanosoma spp., has been identified as a candidate target, and it has been shown previously that substituted pyrrolo[2,3-d]pyrimidines are inhibitors of PTR1 from Trypanosoma brucei (J. Med. Chem. 2010, 53, 221-229). In this study, 61 new pyrrolo[2,3-d]pyrimidines have been prepared, designed with input from new crystal structures of 23 of these compounds complexed with PTR1, and evaluated in screens for enzyme inhibitory activity against PTR1 and in vitro antitrypanosomal activity. Eight compounds were sufficiently active in both screens to take forward to in vivo evaluation. Thus, although evidence for trypanocidal activity in a stage I disease model in mice was obtained, the compounds were too toxic to mice for further development.

  • Organizational Affiliation

    WestCHEM Department of Pure and Applied Chemistry, University of Strathclyde , 295 Cathedral Street, Glasgow G1 1XL, United Kingdom.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
A, B, C, D
288Trypanosoma brucei bruceiMutation(s): 0 
Find proteins for O76290 (Trypanosoma brucei brucei)
Explore O76290 
Go to UniProtKB:  O76290
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO76290
Sequence Annotations
  • Reference Sequence
Small Molecules
Binding Affinity Annotations 
IDSourceBinding Affinity
VS8 Binding MOAD:  4CMC Ki: 200 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Resolution: 1.85 Å
  • R-Value Free: 0.230 
  • R-Value Work: 0.184 
  • R-Value Observed: 0.186 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 74.192α = 90
b = 89.474β = 115.55
c = 84.391γ = 90
Software Package:
Software NamePurpose
XDSdata reduction
SCALAdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2015-01-21
    Type: Initial release
  • Version 1.1: 2017-07-05
    Changes: Data collection
  • Version 1.2: 2023-12-20
    Changes: Data collection, Database references, Derived calculations, Other, Refinement description