Fig. 1
RNA chemical structures and IFN-β activity. a Domain arrangement of RIG-I (1–925). Autoinhibition is shown between CARD2 latch region and HEL2i gate motif. b The chemical structures of an m7G cap and 2′-O-methylation modification at N1 or N2 position are presented. Important features for Cap0, Cap1, Cap0mA, and Cap2 are highlighted. c Schematic representations of studied 8- and 10-mer hairpin RNAs that bear different modifications at the 5′RNA terminus. 3p10l and Cap1-10l represent the molecular signature of viral and self-RNA, respectively. d The IFN-β luciferase signal is plotted as recorded in WT/SMS RIG-I dual reporter assays stimulated with indicated RNAs. Basal IFN-β activity of WT RIG-I in the absence of RNA transfection was subtracted. The significance of differences between groups was evaluated by unpaired Student’s t test (*p < 0.05; **p < 0.01). e ATPase activities of Cap1-10l- and 3p10l-bound WT/SMS RIG-I. The significance of differences between groups was evaluated by unpaired Student’s t test (*p < 0.05)
