DNA constraints allow rational control of macromolecular conformation

As the canonical image of molecular biology, the DNA double helix exemplifies stability and structural integrity. The persistence length of duplex DNA is several hundred base pairs (1 base pair) 3.4 Å) 0.34 nm),1 suggesting that the DNA double helix may be a useful nanoscale construction element.2 Previous efforts used DNA as a static framework for assembling other preformed objects3 or for self-assembly of DNA,4 and dynamic DNA machines have been constructed.5 However, any practical nanotechnology must have moving parts not made solely out of DNA. In this report, we describe for the first time the application of DNA to control the conformation of another macromolecule, RNA. Our efforts suggest a more complete DNA nanotechnology in which the structures of a wide variety of molecules are brought under rational control using DNA. Figure 1A schematically illustrates the application of a covalentl