X-ray crystal structure of IRF-3 and its functional implications.Takahasi, K., Suzuki, N.N., Horiuchi, M., Mori, M., Suhara, W., Okabe, Y., Fukuhara, Y., Terasawa, H., Akira, S., Fujita, T., Inagaki, F.
(2003) Nat Struct Biol 10: 922-927
- PubMed: 14555995
- DOI: https://doi.org/10.1038/nsb1001
- Primary Citation of Related Structures:
- PubMed Abstract:
Transcription factor IRF-3 is post-translationally activated by Toll-like receptor (TLR) signaling and has critical roles in the regulation of innate immunity. Here we present the X-ray crystal structure of the C-terminal regulatory domain of IRF-3(175-427) (IRF-3 175C) at a resolution of 2.3 A. IRF-3 175C is structurally similar to the Mad homology domain 2 of the Smad family. Structural and functional analyses reveal phosphorylation-induced IRF-3 dimerization, which generates an extensive acidic pocket responsible for binding with p300/CBP. Although TLR and Smad signaling are evolutionarily independent, our results suggest that IRF-3 originates from Smad and acquires its function downstream of TLR.
Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita 12 Nishi 6, Kita-ku, Sapporo 060-0812, Japan.