Auto-inhibitory interferon regulation factor-3 (IRF3) transactivation domain

Experimental Data Snapshot

  • Resolution: 2.10 Å
  • R-Value Free: 0.214 
  • R-Value Work: 0.195 
  • R-Value Observed: 0.195 

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Crystal structure of IRF-3 reveals mechanism of autoinhibition and virus induced phospho-activation

Qin, B.Y.Liu, C.Lam, S.S.Srinath, H.Delston, R.Correia, J.J.Derynck, R.Lin, K.

(2003) Nat Struct Biol 10: 913-921

  • DOI: https://doi.org/10.1038/nsb1002
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    IRF-3, a member of the interferon regulatory factor (IRF) family of transcription factors, functions as a molecular switch for antiviral activity. IRF-3 uses an autoinhibitory mechanism to suppress its transactivation potential in uninfected cells, and virus infection induces phosphorylation and activation of IRF-3 to initiate the antiviral responses. The crystal structure of the IRF-3 transactivation domain reveals a unique autoinhibitory mechanism, whereby the IRF association domain and the flanking autoinhibitory elements condense to form a hydrophobic core. The structure suggests that phosphorylation reorganizes the autoinhibitory elements, leading to unmasking of a hydrophobic active site and realignment of the DNA binding domain for transcriptional activation. IRF-3 exhibits marked structural and surface electrostatic potential similarity to the MH2 domain of the Smad protein family and the FHA domain, suggesting a common molecular mechanism of action among this superfamily of signaling mediators.

  • Organizational Affiliation

    Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester 01605, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Interferon regulatory factor 3
A, B
255Homo sapiensMutation(s): 0 
Gene Names: IRF3
UniProt & NIH Common Fund Data Resources
Find proteins for Q14653 (Homo sapiens)
Explore Q14653 
Go to UniProtKB:  Q14653
GTEx:  ENSG00000126456 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ14653
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.10 Å
  • R-Value Free: 0.214 
  • R-Value Work: 0.195 
  • R-Value Observed: 0.195 
  • Space Group: P 4 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 135.545α = 90
b = 135.545β = 90
c = 68.521γ = 90
Software Package:
Software NamePurpose

Structure Validation

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Entry History 

Deposition Data

  • Released Date: 2003-10-14 
  • Deposition Author(s): Qin, B.Y.

Revision History  (Full details and data files)

  • Version 1.0: 2003-10-14
    Type: Initial release
  • Version 1.1: 2008-04-29
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance