3QU6

Crystal structure of IRF-3 DBD free form


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.263 
  • R-Value Work: 0.213 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structures of apo IRF-3 and IRF-7 DNA binding domains: effect of loop L1 on DNA binding.

De Ioannes, P.Escalante, C.R.Aggarwal, A.K.

(2011) Nucleic Acids Res. 39: 7300-7307

  • DOI: 10.1093/nar/gkr325
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Interferon regulatory factors IRF-3 and IRF-7 are transcription factors essential in the activation of interferon-β (IFN-β) gene in response to viral infections. Although, both proteins recognize the same consensus IRF binding site AANNGAAA, they hav ...

    Interferon regulatory factors IRF-3 and IRF-7 are transcription factors essential in the activation of interferon-β (IFN-β) gene in response to viral infections. Although, both proteins recognize the same consensus IRF binding site AANNGAAA, they have distinct DNA binding preferences for sites in vivo. The X-ray structures of IRF-3 and IRF-7 DNA binding domains (DBDs) bound to IFN-β promoter elements revealed flexibility in the loops (L1-L3) and the residues that make contacts with the target sequence. To characterize the conformational changes that occur on DNA binding and how they differ between IRF family members, we have solved the X-ray structures of IRF-3 and IRF-7 DBDs in the absence of DNA. We found that loop L1, carrying the conserved histidine that interacts with the DNA minor groove, is disordered in apo IRF-3 but is ordered in apo IRF-7. This is reflected in differences in DNA binding affinities when the conserved histidine in loop L1 is mutated to alanine in the two proteins. The stability of loop L1 in IRF-7 derives from a unique combination of hydrophobic residues that pack against the protein core. Together, our data show that differences in flexibility of loop L1 are an important determinant of differential IRF-DNA binding.


    Organizational Affiliation

    Department of Structural and Chemical Biology, Mount Sinai School of Medicine, Box 1677, 1425 Madison Avenue, NY 10029, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
IRF3 protein
A, B, C
116Homo sapiensMutation(s): 1 
Gene Names: IRF3
Find proteins for Q14653 (Homo sapiens)
Go to Gene View: IRF3
Go to UniProtKB:  Q14653
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download SDF File 
Download CCD File 
A, B, C
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
NA
Query on NA

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Download CCD File 
A, B
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
CL
Query on CL

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Download CCD File 
A, B, C
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.263 
  • R-Value Work: 0.213 
  • Space Group: P 32 2 1
Unit Cell:
Length (Å)Angle (°)
a = 64.908α = 90.00
b = 64.908β = 90.00
c = 157.621γ = 120.00
Software Package:
Software NamePurpose
JDirectordata collection
PHENIXrefinement
HKL-2000data scaling
PHASERphasing
HKL-2000data reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2011-06-01
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance
  • Version 1.2: 2011-09-14
    Type: Database references