The primary aim of this project is to create a device capable of linking the biological and silicon worlds through a molecular switch. The switch is based on a three-component device – a biological molecular motor driven by ATP, a moving magnetic particle attached to DNA (moved by the motor) and a sensor for easy detection of the moving magnetic particle. The molecular motors to be used are able to ‘pull’ DNA through a bound complex (unlike DNA polymerase and other motors that are linear-tracking motors that move along DNA), which simplifies the movement of the magnetic bead as this can then be readily attached to the free end of the DNA to be ‘pulled’, while the other end of the DNA is surface attached (Figure 1 ).
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(a) The DNA-binding molecular motor binds to DNA, that is attached to a surface, at a specific DNA sequence unique to each motor. (b) The motor ‘pulls’ the DNA through the bound complex toward both the surface and the bound motor. (c) Pulling the DNA also pulls the bound magnetic bead toward the motor. (d) The motor stops at the bead and the motor subunit is released resetting the nanoactuator. (e) After resetting fresh motor protein will allow the nanoactuator to be reused (Firman, 1999; Seidel et al., 2004) |
At the start of the project, two of the Mol Switch Consortium were able to set-up a Magnetic Tweezer system, which has been shown to be capable of single-molecule measurement of such movement of a magnetic particle (Fulconis et al., 2004; Gross, 2004; Zlatanova and Leuba, 2002, 2003) . In addition, it was decided at the outset of the project, that more than one molecular motor would be investigated (in case one motor produced no useful results). The TUDelft Group (in collaboration with Ports) would focus on use of the EcoR124I Type I Restriction-Modification enzyme (for a recent review of such systems see Murray, 2000) , while the French partner (ENS/CNRS) would investigate a range of other motors including chromatin remodelling factors and hybrid enzymes. This arrangement, although limiting the initial amount of integration of ENS/CNRS, within the project, during Year 1, provided security for the research by ensuring the project was not dependent upon a successful outcome with EcoR124I.
A key aspect of the early stages of the project was also to ensure technology transfer between the partners and that key skills available with one group were transferred, as appropriate, to other groups. This was accomplished both by transfer of materials, allowing experience in handling biological materials to be gained, and through laboratory visits between partners, including exchange of data. These events (listed later) have been invaluable in integrating partners and ensuring a complete transfer of skills between the Consortium occurred. This skills-based transfer of experience and knowledge will continue through the rest of the project.
We had a very successful start to the project and Year 1 was particularly successful.