The key to the initial success of this project was the early availability of two Magnetic Tweezer set-ups (TUDelft and ENS/CNRS). Once molecular motor proteins were available to these two groups, rapid progress in the analysis of DNA translocation was possible. This work is detailed in two key papers:
Seidel, R., van Noort, J., van der Scheer, C.,
Bloom, J.G.P., Dekker, N.H., Dutta, C.F., Blundell, A., Robinson, T., Firman,
K., and Dekker, C. (2004) Real-Time Observation of DNA Translocation by the Type
I Restriction-Modification Enzyme EcoR124I. Nature Structural Molecular
Biology 11: 838 - 843.
Saleh, O.A., Perals, C., Barre, F.X., and
Allemand, J.F. (2004) Fast, DNA-sequence independent translocation by FtsK in a
single-molecule experiment. European Molecular Biology Organisation Journal
23: 2430-2439.
In these papers, two motors are described that meet all of the criteria for the proposed Mol Switch device. EcoR124I was shown to be capable of translocating DNA at 550 bp s-1 per motor subunit and can exist in either a single-motor, or, a two-motor complex, with a useful re-setting process that allows increased flexibility for any device. FtsK was shown to be the "Ferrari" of these type of motors and has ten-times the speed of EcoR124I. These motors are both capable of providing the desired switch for the Mol Switch project. They can both move a 1 micron paramagnetic bead over distances of several microns, which should enable us to develop a simple means for detecting the resultant change in the magnetic field.