Fig. 4.

RNA-binding capacities of TW N proteins. (A and B) IBV N protein interactions with synthetic TRS repeats (5′-(CUUAACAA)₄-3′) were measured by SPR assays. The sensorgrams illustrate the N proteins’ binding capacities for TRS repeats on immobilized chips when applied at 0.1 μM (A) or 0.5 μM (B). WT, wild type TW N proteins (black). The N mutants included the T64P (red), T64N (blue), and T123V (green) variants. (C) The relative binding activity ratios summarized from the maximal RNA-binding capacity are presented for each tested protein. *, p < 0.01, one-way ANOVA, Tukey's post hoc test. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of the article).