1TXI

Crystal structure of the vdr ligand binding domain complexed to TX522


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.218 
  • R-Value Work: 0.191 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Superagonistic Action of 14-epi-Analogs of 1,25-Dihydroxyvitamin D Explained by Vitamin D Receptor-Coactivator Interaction

Eelen, G.Verlinden, L.Rochel, N.Claessens, F.De Clercq, P.Vandewalle, M.Tocchini-Valentini, G.Moras, D.Bouillon, R.Verstuyf, A.

(2005) Mol.Pharmacol. 67: 1566-1573

  • DOI: 10.1124/mol.104.008730

  • PubMed Abstract: 
  • Two 14-epi-analogs of 1,25-dihydroxyvitamin D3 [1,25-(OH)(2)D(3)], 19-nor-14-epi-23-yne-1,25-(OH)2D3 (TX522) and 19-nor-14,20-bisepi-23-yne-1,25-(OH)2D3 (TX527), show enhanced antiproliferative (at least 10-fold) and markedly lower calcemic effects b ...

    Two 14-epi-analogs of 1,25-dihydroxyvitamin D3 [1,25-(OH)(2)D(3)], 19-nor-14-epi-23-yne-1,25-(OH)2D3 (TX522) and 19-nor-14,20-bisepi-23-yne-1,25-(OH)2D3 (TX527), show enhanced antiproliferative (at least 10-fold) and markedly lower calcemic effects both in vitro and in vivo, compared with 1,25-(OH)2D3. This study aimed to evaluate their superagonistic effect at the level of interaction between the Vitamin D receptor (VDR) and coactivators. Mammalian two-hybrid assays with VP16-fused VDR and GAL4-DNA-binding-domain-fused steroid receptor coactivator 1 (SRC-1), transcriptional intermediary factor 2 (Tif2), or DRIP205 showed the 14-epi-analogs to be more potent inducers of VDR-coactivator interactions than 1,25-(OH)2D3 (up to 16- and 20-fold stronger induction of VDR-SRC-1 interaction for TX522 and TX527 at 10(-10) M). Similar assays in which metabolism of 1,25-(OH)2D3 was blocked with VID400, a selective inhibitor of the 1,25-(OH)2D3-metabolizing enzyme CYP24, showed that the enhanced potency of these analogs in establishing VDR-coactivator interactions can only partially be accounted for by their increased resistance to metabolic degradation. Crystallization of TX522 complexed to the ligand binding domain of the human VDR demonstrated that the epi-configuration of C14 caused the CD ring of the ligand to shift by 0.5 angstroms, thereby bringing the C12 atom into closer contact with Val300. Moreover, C22 of TX522 made an additional contact with the CD1 atom of Ile268 because of the rigidity of the triple bond-containing side chain. The position and conformation of the activation helix H12 of VDR was strictly maintained. In conclusion, this study provides deeper insight into the docking of TX522 in the LBP and shows that stronger VDR-coactivator interactions underlie the superagonistic activity of the two 14-epi-analogs.


    Organizational Affiliation

    Laboratorium voor Experimentele Geneeskunde en Endocrinologie, Katholieke Universiteit Leuven, Belgium.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Vitamin D receptor
A
263Homo sapiensMutation(s): 0 
Gene Names: VDR (NR1I1)
Find proteins for P11473 (Homo sapiens)
Go to Gene View: VDR
Go to UniProtKB:  P11473
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
TX5
Query on TX5

Download SDF File 
Download CCD File 
A
(1R,3R)-5-((Z)-2-((1R,7AS)-HEXAHYDRO-1-((S)-6-HYDROXY-6-METHYLHEPT-4-YN-2-YL)-7A-METHYL-1H-INDEN-4(7AH)-YLIDENE)ETHYLIDENE)CYCLOHEXANE-1,3-DIOL
19-NOR-14-EPI-23-YNE-1,25 DIHYDROXYVITAMIN D3, TX522
C27 H40 O3
BUDPDEVHCQIFNU-QWVHEKJESA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.218 
  • R-Value Work: 0.191 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 45.259α = 90.00
b = 52.504β = 90.00
c = 132.930γ = 90.00
Software Package:
Software NamePurpose
CNSrefinement
SCALEPACKdata scaling
DENZOdata reduction
CNSphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 2004-07-05 
  • Released Date: 2005-05-10 
  • Deposition Author(s): Moras, D., Rochel, N.

Revision History 

  • Version 1.0: 2005-05-10
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-08-16
    Type: Advisory, Refinement description, Source and taxonomy