Metal ion-directed dynamic splicing of DNA through global conformational change by intramolecular complexation

摘要

Chemically engineered DNAs-in which global conformation can be modulated in response to specific stimuli-could be allosteric functional DNAs themselves or work as a modulator of the functional nucleic acids such as DNAzymes and aptamers. Here, we show that two terpyridines built in the DNA backbone form a stable intramolecular 1:2 complex, [M(terpy)(2)](2+), with divalent transition metal ions. Upon complexation, the DNA conjugates adopt a Omega-shape structure, in which two distal sequences located outside the terpyridines connect with each other to form a continuous segment with a specific structure or sequence. Such a DNA structure is globally controlled by local metal complexation events that can be rationally designed based on general coordination chemistry. This method is regarded as metal ion-directed dynamic sequence edition or DNA splicing. DNAzymes with peroxidase-like activity can thus be regulated by several transition metal ions through sequence edition techniques based on the Omega-motif.