FIGURE 4.

Effect of increasing salt concentrations on binding of RNA sequences to HXB2 RT. Binding of unmodified and 2′-FY modified (A) 70N 1.1 and (B) Arb1 RNAs to HXB2 RT at increasing salt concentrations. Binding was measured using a nitrocellulose filter binding assay with alkaline-treated filters (n = 3). (C) Plot of the percent RNA bound when RT concentration is equal to 100 nM from each of the fitted curves for the four data sets in A,B. A line-of-best-fit is plotted for the first four data points of each set to illustrate the general trend of decreasing binding as salt concentration increases for each sequence.