Crystal structure of IRF-3 bound to the interferon-b enhancerCrystal structure of IRF-3 bound to the interferon-b enhancer

Structural highlights

2o6g is a 6 chain structure with sequence from Homo sapiens. The February 2010 RCSB PDB Molecule of the Month feature on Enhanceosome by David Goodsell is 10.2210/rcsb_pdb/mom_2010_2. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 3.1Å
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

IRF3_HUMAN Key transcriptional regulator of type I interferon (IFN)-dependent immune responses and plays a critical role in the innate immune response against DNA and RNA viruses. Regulates the transcription of type I IFN genes (IFN-alpha and IFN-beta) and IFN-stimulated genes (ISG) by binding to an interferon-stimulated response element (ISRE) in their promoters. Acts as a more potent activator of the IFN-beta (IFNB) gene than the IFN-alpha (IFNA) gene and plays a critical role in both the early and late phases of the IFNA/B gene induction. Found in an inactive form in the cytoplasm of uninfected cells and following viral infection, double-stranded RNA (dsRNA), or toll-like receptor (TLR) signaling, becomes phosphorylated by IKBKE and TBK1 kinases. This induces a conformational change, leading to its dimerization and nuclear localization and association with CREB binding protein (CREBBP) to form dsRNA-activated factor 1 (DRAF1), a complex which activates the transcription of the type I IFN and ISG genes. Can activate distinct gene expression programs in macrophages and can induce significant apoptosis in primary macrophages.

Evolutionary Conservation

 

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

Transcriptional activation of the interferon-beta (IFN-beta) gene requires assembly of an enhanceosome containing ATF-2/c-Jun, IRF-3/IRF-7, and NFkappaB. These factors bind cooperatively to the IFN-beta enhancer and recruit coactivators and chromatin-remodeling proteins to the IFN-beta promoter. We describe here a crystal structure of the DNA-binding domains of IRF-3, IRF-7, and NFkappaB, bound to one half of the enhancer, and use a previously described structure of the remaining half to assemble a complete picture of enhanceosome architecture in the vicinity of the DNA. Association of eight proteins with the enhancer creates a continuous surface for recognizing a composite DNA-binding element. Paucity of local protein-protein contacts suggests that cooperative occupancy of the enhancer comes from both binding-induced changes in DNA conformation and interactions with additional components such as CBP. Contacts with virtually every nucleotide pair account for the evolutionary invariance of the enhancer sequence.

An atomic model of the interferon-beta enhanceosome.,Panne D, Maniatis T, Harrison SC Cell. 2007 Jun 15;129(6):1111-23. PMID:17574024[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

See Also

References

  1. Panne D, Maniatis T, Harrison SC. An atomic model of the interferon-beta enhanceosome. Cell. 2007 Jun 15;129(6):1111-23. PMID:17574024 doi:10.1016/j.cell.2007.05.019

2o6g, resolution 3.10Å

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