Fig. 3: Structure-guided mutations of IFIT2 and IFIT3 abrogate antiviral activity.
a, Zoomed-in view of the central helices in SD II that form a reciprocal salt bridge between IFIT2 (blue) and IFIT3 (yellow). Residue numbers are indicated. b, Importance of salt bridge residues for antiviral activity. HEK293T cells were transiently transfected with empty vector, wild-type (WT) IFIT2 and IFIT3, single E−>K mutant IFIT2 (E155K) and IFIT3 (E153K), or double mutant E−>K/K−>E IFIT2 (E155K K158E) and IFIT3 (E153K K156E). At 24 h post transfection, cells were infected with VSV-GFP (0.05 MOI), and fluorescence images were taken and quantified at 16 hpi (n = 7 biological replicates). c, Previously described RNA-binding residues37,42 (red) mapped on the IFIT2–IFIT3 heterodimer define a heterodimeric RNA-binding surface. d, RNA-binding mutants (mouse IFIT2: R250E, C253E, K254E, R287E; mouse IFIT3: Q249E, K252E, K253E, R286E) were tested for antiviral activity as described in b (n = 4 biological replicates, 32 technical replicates). In b and d, data are represented as mean ± s.e.m. and were analysed with an ordinary one-way ANOVA with Tukey’s multiple comparisons test. ****P < 0.0001.
