1EAO

THE RUNX1 Runt domain at 1.4A resolution: a structural switch and specifically bound chloride ions modulate DNA binding


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.40 Å
  • R-Value Free: 0.173 
  • R-Value Work: 0.141 
  • R-Value Observed: 0.143 

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Literature

The Runx1 Runt Domain at 1.25A Resolution: A Structural Switch and Specifically Bound Chloride Ions Modulate DNA Binding

Backstrom, S.Wolf-Watz, M.Grundstrom, C.Hard, T.Grundstrom, T.Sauer, U.

(2002) J Mol Biol 322: 259

  • DOI: 10.1016/s0022-2836(02)00702-7
  • Primary Citation of Related Structures:  
    1EAQ, 1EAO, 1EAN

  • PubMed Abstract: 
  • The evolutionarily conserved Runt homology domain is characteristic of the RUNX family of heterodimeric eukaryotic transcription factors, including RUNX1, RUNX2 and RUNX3. The genes for RUNX1, also termed acute myeloid leukemia protein 1, AML1, and its dimerization partner core-binding factor beta, CBFbeta, are essential for hematopoietic development and are together the most common targets for gene rearrangements in acute human leukemias ...

    The evolutionarily conserved Runt homology domain is characteristic of the RUNX family of heterodimeric eukaryotic transcription factors, including RUNX1, RUNX2 and RUNX3. The genes for RUNX1, also termed acute myeloid leukemia protein 1, AML1, and its dimerization partner core-binding factor beta, CBFbeta, are essential for hematopoietic development and are together the most common targets for gene rearrangements in acute human leukemias. Here, we describe the crystal structure of the uncomplexed RUNX1 Runt domain at 1.25A resolution and compare its conformation to previously published structures in complex with DNA, CBFbeta or both. We find that complex formation induces significant structural rearrangements in this immunoglobulin (Ig)-like DNA-binding domain. Most pronounced is the movement of loop L11, which changes from a closed conformation in the free Runt structure to an open conformation in the CBFbeta-bound and DNA-bound forms. This transition, which we refer to as the S-switch, and accompanying structural movements that affect other parts of the Runt domain are crucial for sustained DNA binding. The closed to open transition can be induced by CBFbeta alone; suggesting that one role of CBFbeta is to trigger the S-switch and to stabilize the Runt domain in a conformation enhanced for DNA binding.A feature of the Runt domain hitherto unobserved in any Ig-like DNA-binding domain is the presence of two specifically bound chloride ions. One chloride ion is coordinated by amino acid residues that make direct DNA contact. In a series of electrophoretic mobility-shift analyses, we demonstrate a chloride ion concentration-dependent stimulation of the DNA-binding activity of Runt in the physiological range. A comparable DNA-binding stimulation was observed for negatively charged amino acid residues. This suggests a regulatory mechanism of RUNX proteins through acidic amino acid residues provided by activation domains during cooperative interaction with other transcription factors.


    Organizational Affiliation

    Biocrystallography Group, Umeå Centre for Molecular Pathogenesis (UCMP), Umeå University, SE-901 87 Umeå, Sweden.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
RUNT-RELATED TRANSCRIPTION FACTOR 1A, B140Mus musculusMutation(s): 2 
Gene Names: Runx1Aml1Cbfa2Pebp2ab
UniProt
Find proteins for Q03347 (Mus musculus)
Explore Q03347 
Go to UniProtKB:  Q03347
Protein Feature View
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  • Reference Sequence
Small Molecules
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.40 Å
  • R-Value Free: 0.173 
  • R-Value Work: 0.141 
  • R-Value Observed: 0.143 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 91.066α = 90
b = 46.173β = 91.94
c = 62.904γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data reduction
SCALEPACKdata scaling
CNSphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2002-09-12
    Type: Initial release