2X6U

Crystal structure of human TBX5 in the DNA-free form


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.210 

wwPDB Validation 3D Report Full Report


This is version 1.2 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: 10.1016/j.jmb.2010.04.052
  • Primary Citation of Related Structures:  

  • 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 li ...

    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: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
T-BOX TRANSCRIPTION FACTOR TBX5
A
203Homo sapiensMutation(s): 0 
Gene Names: TBX5
Find proteins for Q99593 (Homo sapiens)
Go to Gene View: TBX5
Go to UniProtKB:  Q99593
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PE4
Query on PE4

Download SDF File 
Download CCD File 
A
2-{2-[2-(2-{2-[2-(2-ETHOXY-ETHOXY)-ETHOXY]-ETHOXY}-ETHOXY)-ETHOXY]-ETHOXY}-ETHANOL
POLYETHYLENE GLYCOL PEG4000
C16 H34 O8
PJWQOENWHPEPKI-UHFFFAOYSA-N
 Ligand Interaction
MG
Query on MG

Download SDF File 
Download CCD File 
A
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.210 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 36.710α = 90.00
b = 69.850β = 90.00
c = 80.500γ = 90.00
Software Package:
Software NamePurpose
XDSdata reduction
PHENIXrefinement
PHASERphasing
XSCALEdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-04-28
    Type: Initial release
  • Version 1.1: 2011-05-08
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance