mM) conditions, so that the effect of increasing salt concentrations on the conformation of the protein would not be a factor in the assay. The results are shown in Figure 9A. The Dri peptide shows a clear preference for its identified consensus site in this assay, as reported previously (4). A 500-fold excess of cold competitor with the correct consensus sequence competes effectively with the labeled probe, while the altered sequence, even at 1000-fold excess, shows little ability to displace the peptide (Figure 9A, panel 2). In contrast, the AT-rich consensus site does not compete for p270 binding any better than the mutant oligonucleotide (Figure 9A, panel 1).
