Rational design of a reversible Mg2+/EDTA-controlled molecular switch based on a DNA minidumbbell.

Here we report that incorporation of an abasic site to DNA minidumbbells formed by natural sequences can lead to significant enhancements in their thermodynamic stability. Based on these stable minidumbbells, the first metal ion-controlled molecular switch which can regulate instant and reversible DNA duplex formation and dissociation has been constructed.