3JZB

Crystal Structure of TR-alfa bound to the selective thyromimetic TRIAC

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.01 Å
  • R-Value Free: 0.199 
  • R-Value Work: 0.171 
  • R-Value Observed: 0.173 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history. 


Literature

Gaining ligand selectivity in thyroid hormone receptors via entropy.

Martinez, L., Nascimento, A.S., Nunes, F.M., Phillips, K., Aparicio, R., Dias, S.M., Figueira, A.C., Lin, J.H., Nguyen, P., Apriletti, J.W., Neves, F.A., Baxter, J.D., Webb, P., Skaf, M.S., Polikarpov, I.

(2009) Proc Natl Acad Sci U S A 106: 20717-20722

  • DOI: 10.1073/pnas.0911024106
  • Primary Citation of Related Structures:  
    3JZB, 3JZC

  • PubMed Abstract: 

    • Nuclear receptors are important targets for pharmaceuticals, but similarities between family members cause difficulties in obtaining highly selective compounds. Synthetic ligands that are selective for thyroid hormone (TH) receptor beta (TRbeta) vs. TRalpha reduce cholesterol and fat without effects on heart rate; thus, it is important to understand TRbeta-selective binding ...

    Nuclear receptors are important targets for pharmaceuticals, but similarities between family members cause difficulties in obtaining highly selective compounds. Synthetic ligands that are selective for thyroid hormone (TH) receptor beta (TRbeta) vs. TRalpha reduce cholesterol and fat without effects on heart rate; thus, it is important to understand TRbeta-selective binding. Binding of 3 selective ligands (GC-1, KB141, and GC-24) is characterized at the atomic level; preferential binding depends on a nonconserved residue (Asn-331beta) in the TRbeta ligand-binding cavity (LBC), and GC-24 gains extra selectivity from insertion of a bulky side group into an extension of the LBC that only opens up with this ligand. Here we report that the natural TH 3,5,3'-triodothyroacetic acid (Triac) exhibits a previously unrecognized mechanism of TRbeta selectivity. TR x-ray structures reveal better fit of ligand with the TRalpha LBC. The TRbeta LBC, however, expands relative to TRalpha in the presence of Triac (549 A(3) vs. 461 A(3)), and molecular dynamics simulations reveal that water occupies the extra space. Increased solvation compensates for weaker interactions of ligand with TRbeta and permits greater flexibility of the Triac carboxylate group in TRbeta than in TRalpha. We propose that this effect results in lower entropic restraint and decreases free energy of interactions between Triac and TRbeta, explaining subtype-selective binding. Similar effects could potentially be exploited in nuclear receptor drug design.

    Organizational Affiliation: 

    Instituto de Química, Universidade Estadual de Campinas, SP 13084-862, Campinas, Brazil.



Macromolecules
Find similar proteins by: 
(by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
THRA protein A267Homo sapiensMutation(s): 0 
Gene Names: THRA, hCG_1749555, EAR7, ERBA1, NR1A1, THRA1, THRA2
Find proteins for P10827 (Homo sapiens)
Explore P10827 
Go to UniProtKB:  P10827
NIH Common Fund Data Resources
PHAROS:  P10827
GTEx:  ENSG00000126351
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
4HY
Query on 4HY
Download Ideal Coordinates CCD File 
A
[4-(4-HYDROXY-3-IODO-PHENOXY)-3,5-DIIODO-PHENYL]-ACETIC ACID
C14 H9 I3 O4
UOWZUVNAGUAEQC-UHFFFAOYSA-N		 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
CAS
Query on CAS		AL-PEPTIDE LINKINGC5 H12 As N O2 SCYS
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
4HYIC50:  0.10000000149011612   nM  Binding MOAD
4HYIC50 :  0.9700000286102295   nM  PDBBind
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.01 Å
  • R-Value Free: 0.199 
  • R-Value Work: 0.171 
  • R-Value Observed: 0.173 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 60.02α = 90
b = 80.825β = 90
c = 102.355γ = 90
Software Package:
Software NamePurpose
MAR345dtbdata collection
MOLREPphasing
PHENIXrefinement
MOSFLMdata reduction
SCALAdata scaling

Structure Validation

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View more in-depth experimental data

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2009-12-08
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance