Triplex formation by oligodeoxyribonucleotides involving the formation of X-U-A triads

Ultraviolet melting experiments were carried out to study the stabilities of oligodeoxyribonucleotide triplexes containing single pyrimidine (Py)-purine (Pu) base pair. The Py-Pu base pair interrupts an otherwise Pu-Py base pair motif. In particular, the formation of X-U-A triads, where U is dexoyuridine, was focused on. Triplex formation in this system was also compared with that involving X-C-G and X-T-A base triads.