A DNA Nanotransport Device Powered by Polymerase φ29

Polymerases are a family of enzymes responsible for copying or replication of nucleic acids (DNA or RNA) templates and hence sustenance of life processes. In this paper, we present a method to exploit a strand-displacing polymerase phi 29 as a driving force for nanoscale transportation devices. The principal idea behind the device is strong strand displacement ability of phi 29, which can displace any DNA strand from its template while extending a primer hybridized to the template. This capability of phi 29 is used to power the movement of a target nanostructure on a DNA track. The major advantage of using a polymerase driven nanotransportation device as compared to other existing nanorobotical devices is its speed. phi 29 polymerase can travel at the rate of 2000 nucleotides per minute(1) at room temperature, which translates to approximately 680 nm min(-1) on a nanostructure. We also demonstrate transportation of a DNA cargo on a DNA track with the help of fluorescence resonance electron transfer data.