Using gene regulation to program DNA-based molecular devices.

Molecular machines based on DNA have the ability to perform tasks on the nanometer scale. In addition to movements such as stretching and rotation, these devices can execute useful functions such as grabbing and releasing a single protein and walking a defined distance along a circular or linear track. As increasingly more machines are developed with functionality, it is desirable to be able to incorporate the devices into living organisms and artificially control within them processes on the molecular scale. Because most DNA nanomachines operate through hybridization of the machine with manually added single-stranded DNA (ssDNA) signals, it is difficult to control the devices in vivo. The integration of the instructions for nanomachine operation into a DNA gene and the genetic regulation of the expression of these instructions can enable these nanodevices to function independently and respond to environmental stimuli. This effort can be viewed in the larger context of using biological design principles for nanotechnology, a field sometimes referred to as synthetic biology. In this communication, we demonstrate that the operation of DNA nanomachines can be controlled in vitro using gene regulation switches, in particular those of E. coli bacteria.