Oligonucleotides-transformers for molecular biology and nanoengineering

•A new class of oligonucleotide sequences is described.•The likely roles of oligonucleotides-transformers in living organisms are described.•Applications of oligonucleotides-transformers in nanoengineering are proposed.•Biotechnological usage of oligonucleotides-transformers is summarized. In the present review, numerous experimental and theoretical data describing the properties of non-canonical DNA structures (NSs) are analyzed. NSs (G-quadruplex, i-motif, hairpin, and triplex) play an important role in epigenetic processes (including the genetic variability of viruses), are prone to energetically low-cost conformational transformations and can very effectively be used in the design of nanoscale devices. Numerous experimental data have been analyzed in connection with the so-called oligonucleotides-transformers (nucleotide sequences that able to fold not only into one, but also into several NSs). These sequences were recently predicted by our calculations using automata and graph theories (“Dafna” algorithm). Possible applications of the oligonucleotides-transformers in nanoengineering and genetic editing of organisms are considered.