B. EMSA analysis of yTBP binding to DNA. We incubated 5 nM FAM-labeled oligonucleotide (TGTATGTATATAAAAC) with indicated concentrations of purified yTBP (0.125 to 8 μM) and then analyzed binding by 6% non-denaturing PAGE. Band intensities of free DNA from the gels (Top panel) were quantified and plotted (Bottom panel). 