1NJS

human GAR Tfase in complex with hydrolyzed form of 10-trifluoroacetyl-5,10-dideaza-acyclic-5,6,7,8-tetrahydrofolic acid


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.98 Å
  • R-Value Free: 0.247 
  • R-Value Work: 0.227 
  • R-Value Observed: 0.228 

Starting Model: experimental
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Ligand Structure Quality Assessment 


This is version 1.3 of the entry. See complete history


Literature

Rational Design, Synthesis, Evaluation, and Crystal Structure of a Potent Inhibitor of Human GAR Tfase: 10-(Trifluoroacetyl)-5,10-dideazaacyclic-5,6,7,8-tetrahydrofolic Acid

Zhang, Y.Desharnais, J.Marsilje, T.H.Li, C.Hedrick, M.P.Gooljarsingh, L.T.Tavassoli, A.Benkovic, S.J.Olson, A.J.Boger, D.L.Wilson, I.A.

(2003) Biochemistry 42: 6043-6056

  • DOI: https://doi.org/10.1021/bi034219c
  • Primary Citation of Related Structures:  
    1NJS

  • PubMed Abstract: 

    Glycinamide ribonucleotide transformylase (GAR Tfase) has been the target of anti-neoplastic intervention for almost two decades. Here, we use a structure-based approach to design a novel folate analogue, 10-(trifluoroacetyl)-5,10-dideazaacyclic-5,6,7,8-tetrahydrofolic acid (10-CF(3)CO-DDACTHF, 1), which specifically inhibits recombinant human GAR Tfase (K(i) = 15 nM), but is inactive (K(i) > 100 microM) against other folate-dependent enzymes that have been examined. Moreover, compound 1 is a potent inhibitor of tumor cell proliferation (IC(50) = 16 nM, CCRF-CEM), which represents a 10-fold improvement over Lometrexol, a GAR Tfase inhibitor that has been in clinical trials. Thus, this folate analogue 1 is among the most potent and selective inhibitors known toward GAR Tfase. Contributing to its efficacious activity, compound 1 is effectively transported into the cell by the reduced folate carrier and intracellularly sequestered by polyglutamation. The crystal structure of human GAR Tfase with folate analogue 1 at 1.98 A resolution represents the first structure of any GAR Tfase to be determined with a cofactor or cofactor analogue without the presence of substrate. The folate-binding loop of residues 141-146, which is highly flexible in both Escherichia coli and unliganded human GAR Tfase structures, becomes highly ordered upon binding 1 in the folate-binding site. Computational docking of the natural cofactor into this and other apo or complexed structures provides a rational basis for modeling how the natural cofactor 10-formyltetrahydrofolic acid interacts with GAR Tfase, and suggests that this folate analogue-bound conformation represents the best template to date for inhibitor design.


  • Organizational Affiliation

    Department of Molecular Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Phosphoribosylglycinamide formyltransferase
A, B
209Homo sapiensMutation(s): 0 
Gene Names: GART
EC: 2.1.2.2
UniProt & NIH Common Fund Data Resources
Find proteins for P22102 (Homo sapiens)
Explore P22102 
Go to UniProtKB:  P22102
PHAROS:  P22102
GTEx:  ENSG00000159131 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP22102
Sequence Annotations
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  • Reference Sequence
Small Molecules
Binding Affinity Annotations 
IDSourceBinding Affinity
KEU PDBBind:  1NJS Ki: 15 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.98 Å
  • R-Value Free: 0.247 
  • R-Value Work: 0.227 
  • R-Value Observed: 0.228 
  • Space Group: P 31 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 126.235α = 90
b = 126.235β = 90
c = 94.419γ = 120
Software Package:
Software NamePurpose
HKL-2000data collection
SCALEPACKdata scaling
AMoREphasing
REFMACrefinement
HKL-2000data reduction

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Revision History  (Full details and data files)

  • Version 1.0: 2003-06-10
    Type: Initial release
  • Version 1.1: 2008-04-29
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2023-08-16
    Changes: Data collection, Database references, Derived calculations, Refinement description, Structure summary