FIGURE 2.

Competition for U2AF⁶⁵ binding to the consensus sequence by oligonucleotides with single nucleotide substitutions. Graphic representation of competition experiments with oligonucleotides containing single nucleotide substitutions at the indicated position. Transgenic extract was ultraviolet cross-linked with ³²P-labeled U₄CAGG-containing oligonucleotides in the presence of variant competitors. Increasing amounts of competitor oligonucleotides were in 2.5-fold, fivefold, 10-fold, and 25-fold molar excess over labeled RNA, which was always present at 8 ng. Bands were quantified and normalized using the PhosphorImager system from Molecular Dynamics. U indicated by red circles; A, green squares; C, blue diamonds; and G, black triangles.