Guanine cytosine triplexes

Besides the canonical triplexes formed, for example, between thymine and the adenine-thymine base pair and cytosine and the guanine-cytosine base pair other combinations have been suggested to form stable triplexes, e.g. G-TA, G-GC and T-GC [43], The stability of triplexes depends on pH, ionic strength, temperature, and, in cases where the Watson-Crick duplex is part of a plasmid DNA, it depends on supercoil density [44]. 

---