1PUF

Crystal Structure of HoxA9 and Pbx1 homeodomains bound to DNA


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.268 
  • R-Value Work: 0.233 
  • R-Value Observed: 0.233 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

STRUCTURE OF HOXA9 AND PBX1 BOUND TO DNA: HOX HEXAPEPTIDE AND DNA RECOGNITION ANTERIOR TO POSTERIOR

LARONDE-LEBLANC, N.A.Wolberger, C.

(2003) Genes Dev 17: 2060-2072

  • DOI: 10.1101/gad.1103303
  • Primary Citation of Related Structures:  
    1PUF

  • PubMed Abstract: 
  • The HOX/HOM superfamily of homeodomain proteins controls cell fate and segmental embryonic patterning by a mechanism that is conserved in all metazoans. The linear arrangement of the Hox genes on the chromosome correlates with the spatial distributio ...

    The HOX/HOM superfamily of homeodomain proteins controls cell fate and segmental embryonic patterning by a mechanism that is conserved in all metazoans. The linear arrangement of the Hox genes on the chromosome correlates with the spatial distribution of HOX protein expression along the anterior-posterior axis of the embryo. Most HOX proteins bind DNA cooperatively with members of the PBC family of TALE-type homeodomain proteins, which includes human Pbx1. Cooperative DNA binding between HOX and PBC proteins requires a residue N-terminal to the HOX homeodomain termed the hexapeptide, which differs significantly in sequence between anterior- and posterior-regulating HOX proteins. We report here the 1.9-A-resolution structure of a posterior HOX protein, HoxA9, complexed with Pbx1 and DNA, which reveals that the posterior Hox hexapeptide adopts an altered conformation as compared with that seen in previously determined anterior HOX/PBC structures. The additional nonspecific interactions and altered DNA conformation in this structure account for the stronger DNA-binding affinity and altered specificity observed for posterior HOX proteins when compared with anterior HOX proteins. DNA-binding studies of wild-type and mutant HoxA9 and HoxB1 show residues in the N-terminal arm of the homeodomains are critical for proper DNA sequence recognition despite lack of direct contact by these residues to the DNA bases. These results help shed light on the mechanism of transcriptional regulation by HOX proteins and show how DNA-binding proteins may use indirect contacts to determine sequence specificity.


    Organizational Affiliation

    Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205-2185, USA.



Macromolecules

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Entity ID: 3
MoleculeChainsSequence LengthOrganismDetailsImage
Homeobox protein Hox-A9A77Mus musculusMutation(s): 0 
Gene Names: Hoxa9Hox-1.7Hoxa-9
Find proteins for P09631 (Mus musculus)
Explore P09631 
Go to UniProtKB:  P09631
Protein Feature View
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  • Reference Sequence
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Entity ID: 4
MoleculeChainsSequence LengthOrganismDetailsImage
Pre-B-cell leukemia transcription factor-1B73Homo sapiensMutation(s): 0 
Gene Names: PBX1PRL
Find proteins for P40424 (Homo sapiens)
Explore P40424 
Go to UniProtKB:  P40424
NIH Common Fund Data Resources
PHAROS  P40424
Protein Feature View
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  • Reference Sequence
  • Find similar nucleic acids by:  Sequence   |   Structure
  • Entity ID: 1
    MoleculeChainsLengthOrganismImage
    5'-D(*AP*CP*TP*CP*TP*AP*TP*GP*AP*TP*TP*TP*AP*CP*GP*AP*CP*GP*CP*T)-3'D20N/A
    • Find similar nucleic acids by:  Sequence   |   Structure
    • Entity ID: 2
      MoleculeChainsLengthOrganismImage
      5'-D(*TP*AP*GP*CP*GP*TP*CP*GP*TP*AP*AP*AP*TP*CP*AP*TP*AP*GP*AP*G)-3'E20N/A
      Small Molecules
      External Ligand Annotations 
      IDBinding Affinity (Sequence Identity %)
      DNAKd :  230   nM  PDBBind
      Experimental Data & Validation

      Experimental Data

      • Method: X-RAY DIFFRACTION
      • Resolution: 1.90 Å
      • R-Value Free: 0.268 
      • R-Value Work: 0.233 
      • R-Value Observed: 0.233 
      • Space Group: C 2 2 21
      Unit Cell:
      Length ( Å )Angle ( ˚ )
      a = 60.769α = 90
      b = 114.853β = 90
      c = 108.17γ = 90
      Software Package:
      Software NamePurpose
      DENZOdata reduction
      SCALEPACKdata scaling
      AMoREphasing
      CNSrefinement

      Structure Validation

      View Full Validation Report



      Entry History 

      Deposition Data

      Revision History 

      • Version 1.0: 2003-09-02
        Type: Initial release
      • Version 1.1: 2008-04-29
        Changes: Version format compliance
      • Version 1.2: 2011-07-13
        Changes: Version format compliance