Abstract: Our study aimed at verifying the interaction between IRF6 and IFN-β and providing foundation for the structural determination of IRF6. In this study, high throughput cloning, expression and purification were used to get a highly purified and soluble expression of the N-terminal domain of IRF6 (amino acid from 1 to 128). Electrophoretic mobility shift assay (EMSA) was used to qualitatively validated the definite interaction between the N-terminal domain of IRF6 with a dsDNA fragment from the promotor of IFN-β. The complex of the protein and the ds-DNA fragment was used, and hanging drop vapor diffusion method was applied for crystallization. Finally, a crystal of a high resolution of 2.68 was obtained by the method of crystallography, which could provide sufficient information for the structural analysis. Our study verified the N-terminal domain of IRF6 was a DNA-binding region which regulates the transcription and function of IFN-β. Crystals of high quality of IRF6 could be obtained by means of assembling the protein-dsDNA complex, which laid the foundation for the 3D structure determination of IRF6. The research was of great significance of studying the function and regulatory mechanism of IRF6 and IFN.

Key words: interferon regulatory factor 6, INF-β, purification, crystallization