Figure 4.

Competition assays to determine the affinity binding and specificity of RBP7910 to the labeled poly AU sequence. (A) Titration of RBP7910 protein over 1 nM concentration of labeled poly AU RNA. The first lane is the labeled poly AU in the absence of the protein. The protein-RNA bound complexes are shown by a black triangle. Middle panel, RBP7910 RNA binding specificity was checked using unlabeled homologous poly AU competitor in a competition assay. RBP7910 at 40 nM was incubated with labeled poly AU in the absence and presence of increasing concentrations of unlabeled competitor. Asterisk indicates the input labeled RNA in the absence of the protein and the white star shows the labeled RNA with protein in the absence of the competitor RNA. Numbers above the panels indicate the fold excess of the unlabeled RNA competitor and numbers below of each panel is the % shift in the presence of competitor RNA which normalized to the shift in the absence of a competitor (B), same as A; except than using different competitors. Competitor RNAs mentioned above each panel.