Small Circular Oligodeoxynucleotides Achieved from Self‐Assembling Entities

Self-recognition rather than complementarity defines the self-assembly (a) of two cytosine-rich oligodeoxynucleotides in the compact i-motif shown (CC+ base pairs, dark circles). When the 5′-terminal phosphate is activated, phosphodiester bonds form between the termini of the linear sequences, resulting in two circular oligodeoxynucleotides (b), which disassociate on denaturation (c).