1PUF

Crystal Structure of HoxA9 and Pbx1 homeodomains bound to DNA


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.268 
  • R-Value Work: 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

  • 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

Find similar proteins by: Sequence  |  Structure


Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
Homeobox protein Hox-A9
A
77Mus musculusMutation(s): 0 
Gene Names: Hoxa9 (Hox-1.7, Hoxa-9)
Find proteins for P09631 (Mus musculus)
Go to UniProtKB:  P09631
Entity ID: 4
MoleculeChainsSequence LengthOrganismDetails
Pre-B-cell leukemia transcription factor-1
B
73Homo sapiensMutation(s): 0 
Gene Names: PBX1 (PRL)
Find proteins for P40424 (Homo sapiens)
Go to Gene View: PBX1
Go to UniProtKB:  P40424
Entity ID: 1
MoleculeChainsLengthOrganism
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
Entity ID: 2
MoleculeChainsLengthOrganism
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
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.268 
  • R-Value Work: 0.233 
  • Space Group: C 2 2 21
Unit Cell:
Length (Å)Angle (°)
a = 60.769α = 90.00
b = 114.853β = 90.00
c = 108.170γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
CNSrefinement
DENZOdata reduction
AMoREphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

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