Figure 3.

Pr55^Gag interaction with N1-600WT and N1-600 ΔSL1 RNAs, and with M1-615WT and M1-615 SL1 ΔRNAs. (A) and (C) Increasing RNA concentrations were added to 100 nM Pr55^Gag. The resulting binding curves corresponding to Pr55^Gag interaction with N1-600 ΔSL1 or M1-615 SL1 ΔRNAs (red circles) were fitted according to the Scatchard model,¹¹¹ while the experimental curves resulting from Pr55^Gag interaction with N1-600WT or M1-615WT ΔRNAs (black squares) were fitted with a Scatchard-like equation corresponding to a 2-binding sites model (Table 2). The residuals were plotted for each fit. (B) and (D). The Scatchard plots relative to N1-600WT and M1-615WT ΔRNAs did not display a linear pattern, confirming the presence of 2 classes of binding sites, while the plots relative to N1-600 ΔSL1 and M1-615 ΔSL1 RNAs yielded a linear pattern, confirming the presence of only one class of binding site.