2X6U

Crystal structure of human TBX5 in the DNA-free form


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.210 
  • R-Value Observed: 0.213 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Structural Basis of Tbx5-DNA Recognition: The T-Box Domain in its DNA-Bound and -Unbound Form.

Stirnimann, C.U.Ptchelkine, D.Grimm, C.Muller, C.W.

(2010) J Mol Biol 400: 71

  • DOI: https://doi.org/10.1016/j.jmb.2010.04.052
  • Primary Citation of Related Structures:  
    2X6U, 2X6V

  • PubMed Abstract: 

    TBX5, a member of the T-box transcription factor family, plays an important role in heart and limb development. More than 60 single point or deletion mutations of human TBX5 are associated with Holt-Oram syndrome that manifests itself as heart and limb malformations in 1 out of 100,000 live births. The majority of these mutations are located in the TBX5 T-box domain. We solved the crystal structures of the human TBX5 T-box domain in its DNA-unbound form and in complex with a natural DNA target site allowing for the first time the comparison between unbound and DNA-bound forms. Our analysis identifies a 3(10)-helix at the C-terminus of the T-box domain as an inducible recognition element, critically required for the interaction with DNA, as it only forms upon DNA binding and is unstructured in the DNA-unbound form. Using circular dichroism, we characterized the thermal stability of six TBX5 mutants containing single point mutations in the T-box domain (M74V, G80R, W121G, G169R, T223M, and R237W) and compared them with wild-type protein. Mutants G80R and W121G show drastically reduced thermal stability, while the other mutants only show a marginal stability decrease. For all TBX5 mutants, binding affinities to specific and nonspecific DNA sequences were determined using isothermal titration calorimetry. All TBX5 mutants show reduced binding affinities to a specific DNA target site, although to various degrees. Interestingly, all tested TBX5 mutants differ in their ability to bind unspecific DNA, indicating that both sequence-specific and unspecific binding might contribute to the misregulation of target gene expression.


  • Organizational Affiliation

    European Molecular Biology Laboratory, Structural and Computational Biology Unit, Meyerhofstrasse 1, 69117 Heidelberg, Germany.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
T-BOX TRANSCRIPTION FACTOR TBX5203Homo sapiensMutation(s): 0 
UniProt & NIH Common Fund Data Resources
Find proteins for Q99593 (Homo sapiens)
Explore Q99593 
Go to UniProtKB:  Q99593
PHAROS:  Q99593
GTEx:  ENSG00000089225 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ99593
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.210 
  • R-Value Observed: 0.213 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 36.71α = 90
b = 69.85β = 90
c = 80.5γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata reduction
XSCALEdata scaling
PHASERphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2010-04-28
    Type: Initial release
  • Version 1.1: 2011-05-08
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2024-05-08
    Changes: Data collection, Database references, Derived calculations, Other