1NWQ

CRYSTAL STRUCTURE OF C/EBPALPHA-DNA COMPLEX


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.275 
  • R-Value Work: 0.221 
  • R-Value Observed: 0.221 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Structural Basis for DNA Recognition by the Basic Region Leucine Zipper Transcription Factor CCAAT/enhancer Binding Protein Alpha

Miller, M.Shuman, J.D.Sebastian, T.Dauter, Z.Johnson, P.F.

(2003) J Biol Chem 278: 15178-15184

  • DOI: 10.1074/jbc.M300417200
  • Primary Citation of Related Structures:  
    1NWQ

  • PubMed Abstract: 
  • CCAAT/enhancer-binding proteins (C/EBPs) are basic region leucine zipper (bZIP) transcription factors that regulate cell differentiation, growth, survival, and inflammation. To understand the molecular basis of DNA recognition by the C/EBP family we ...

    CCAAT/enhancer-binding proteins (C/EBPs) are basic region leucine zipper (bZIP) transcription factors that regulate cell differentiation, growth, survival, and inflammation. To understand the molecular basis of DNA recognition by the C/EBP family we determined the x-ray structure of a C/EBPalpha bZIP polypeptide bound to its cognate DNA site (A(-5)T(-4)T(-3)G(-2)C(-1)G(1)C(2)A(3)A(4)T(5)) and characterized several basic region mutants. Binding specificity is provided by interactions of basic region residues Arg(289), Asn(292), Ala(295), Val(296), Ser(299), and Arg(300) with DNA bases. A striking feature of the C/EBPalpha protein-DNA interface that distinguishes it from known bZIP-DNA complexes is the central role of Arg(289), which is hydrogen-bonded to base A(3), phosphate, Asn(292) (invariant in bZIPs), and Asn(293). The conformation of Arg(289) is also restricted by Tyr(285). In accordance with the structural model, mutation of Arg(289) or a pair of its interacting partners (Tyr(285) and Asn(293)) abolished C/EBPalpha binding activity. Val(296) (Ala in most other bZIPs) contributes to C/EBPalpha specificity by discriminating against purines at position -3 and imposing steric restraints on the invariant Arg(300). Mutating Val(296) to Ala strongly enhanced C/EBPalpha binding to cAMP response element (CRE) sites while retaining affinity for C/EBP sites. Thus, Arg(289) is essential for formation of the complementary protein-DNA interface, whereas Val(296) functions primarily to restrict interactions with related sequences such as CRE sites rather than specifying binding to C/EBP sites. Our studies also help to explain the phenotypes of mice carrying targeted mutations in the C/EBPalpha bZIP region.


    Organizational Affiliation

    Protein Structure Section, Macromolecular Crystallography Laboratory, and the Regulation of Cell Growth Laboratory, National Cancer Institute-Frederick, Frederick, Maryland 21702-1201, USA. millerm@ncifcrf.gov



Macromolecules

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Entity ID: 3
MoleculeChainsSequence LengthOrganismDetailsImage
CCAAT/enhancer binding protein alphaAC62Rattus norvegicusMutation(s): 0 
Gene Names: Cebpa
Find proteins for P05554 (Rattus norvegicus)
Explore P05554 
Go to UniProtKB:  P05554
Protein Feature View
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  • Reference Sequence
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(by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsLengthOrganismImage
5'-D(*AP*AP*AP*CP*TP*GP*GP*AP*TP*TP*GP*CP*GP*CP*AP*AP*TP*AP*GP*GP*A)-3'D21N/A
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(by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsLengthOrganismImage
5'-D(*TP*TP*CP*CP*TP*AP*TP*TP*GP*CP*GP*CP*AP*AP*TP*CP*CP*AP*GP*TP*T)-3'B21N/A
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.275 
  • R-Value Work: 0.221 
  • R-Value Observed: 0.221 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 140.892α = 90
b = 53.089β = 90
c = 67.406γ = 90
Software Package:
Software NamePurpose
CNSrefinement
HKL-2000data reduction
SCALEPACKdata scaling
AMoREphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2003-05-13
    Type: Initial release
  • Version 1.1: 2008-04-29
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance