Figure 3. Imp4p prefers long single-stranded TG1–3 DNA for binding.
(A) 32P-labelled TG15, TG20, TG25, TG30, TG35 or TG40 (5 nM of each) was mixed with 0, 0.15 or 1.5 μM purified Imp4p before subjection to gel-shift assay. (B) Quantitative data from PhosphorImager analysis of gel mobility shifts were used to determine the equilibrium binding constant. Concentrations of Imp4p from 0 to 120 μM were used in these analyses. The fraction of DNA bound/free DNA is plotted against the Imp4p concentration. Representative plots for TG15 (left-hand panel) and TG40 (right-hand panel) are shown.