Binding of Triple Helix Forming Oligonucleotides to Sites in Gene Promoters

A class of triplex-forming oligodeoxyribonucleotides (TFOs) is described that can bind to naturally occuring sites in duplex DNA at physiological pH in the presence of magnesium. The data are consistent with a structure in which the TFO binds in major groove of double-stranded DNA to form a three-stranded complex that is superfically similar to previously described triplexes