Addressable molecular tweezers for DNA-templated coupling reactions

Here we report the construction of fully addressable DNA-based molecular tweezers to actuate coupling reactions in a programmable fashion. Three tweezers, each bearing two coupling reactants, are self-assembled on a linear DNA track. A fourth tweezer floating freely in solution can be brought to any one of the tweezers and close them by the addition of a unique pair of "fuel" DNA strands. The coupling reactions happen when the tweezers are closed, and this can be controlled sequentially from one tweezer to another. A molecular device of this kind would not only enable programmable chemical reactions but also allow distance-dependent control of biomolecular interactions.