Skip to main content
. 2018 Jul 24;2(2):161–173.

Figure 2.

Figure 2

Identification of PPBF, a factor that binds specifically to a palindromic sequence in the proximal regulatory region of the U4X gene. EMSAs were performed by incubating increasing amounts of affinity-purified factor, PPBF, with various synthetic oligonucleotides and restriction fragments that contained DNA sequences from the U4X gene proximal region. The sequences of the synthetic DNA oligonucleotides are shown below the autoradiograms. The U4X Pal/PSE oligonucleotide contained the complete PSE and overlapping palindromic sequence, whereas the U4X Pal and U4X PSE oligonucleotides contained complete sequences only for the palindrome or the PSE respectively. Wild-type nucleotides are shown in upper case, and the double-ended arrow indicates the position of the palindrome. The restriction fragment designated U4X proximal contained U4X sequences from position −132 in the 5′ flanking DNA to position 2 in the coding region of the gene. The U4X ΔBssH II fragment was similar, except that nucleotides from positions −105 to −64 had been deleted by BssH II digestion and re-ligation. Only DNA oligonucleotides or fragments that contained the intact palindromic sequence were able to form the upper complex, c2.