DNA Structural Changes Induced by Intermolecular Triple Helix Formation.

ABSTRACT: DNase I footprints of intermolecular DNA triplexes are often accompanied by enhanced cleavage at the 3'-end of the target site at the triplex-duplex junction. We have systematically studied the sequence dependence of this effect by examining oligonucleotide binding to sites flanked by each base in turn. For complexes with a terminal T.AT triplet, the greatest enhancement is seen with ApC, followed by ApG and ApT, with the weakest enhancement at ApA. Similar DNase I enhancements were observed for a triplex with a terminal C+.GC triplet, though with little difference between the different GpN sites. Enhanced reactivity to diethylpyrocarbonate was observed at As that flank the triplex-duplex junction at AAA or AAC but not AAG or AAT. Fluorescence melting experiments demonstrated that the flan

SUBMITTER: Sayoh I 

PROVIDER: S-EPMC6990630 | biostudies-literature | 2020 Jan

REPOSITORIES: biostudies-literature