BIOTEC - Biotechnology Center TU Dresden

Translocation of enzymes along DNA, driven by molecular motors, plays a crucial role during many vital DNA-processing steps in the cellular cycle, including DNA repair, recombination, replication, transcription and restriction. These enzymes use the energy stored in ATP or other NTPs and convert it into directional motion along their template. Very often motion does not just occur just by itself but is accompanied by reshaping or processing the DNA template. Understanding the mechanisms how DNA motors couple the ATP hydrolysis to achieve their function (motion, DNA processing) will help to gain much deeper insight in the cellular processes, which are driven by these motors.

 
Artistic view on an enzyme motor pulling on DNA in a magnetic tweezers setup

 

In our biophysically oriented group we study DNA translocating motors on the level of a single-molecule. Recent advances in single-molecule techniques allow to follow the action of a single molecular motor in real time. We apply magnetic tweezers, which are an excellent tool to study the translocation of single enzyme complexes on DNA. They allow to stretch and twist a single DNA molecule and to measure its end-to-end distance in real-time, while it is getting processed by an enzyme. If a DNA translocating motor pulls in DNA, its end-to-end distance changes and can thus be monitored. Current research projects involve dsDNA motors, which belong to the Super family 2 of helicases (e.g. Type I and Type III restriction enzymes) as well as viral helicases, which function in DNA replication. More information can be found on the personal webpage.

Brownian motion of a magnetic bead in the tweezers bound to a stretched DNA molecule

1. A. Crut, D.A. Koster, R. Seidel, C. H. Wiggins, N.H. Dekker.
   Fast dynamics of supercoiled DNA revealed by single-molecule experiments
   Proceedings of the National Academy of Sciences 104(29) 11957-11962 (2007) PDF  Suppl. data
   
   
2. R. Seidel & C. Dekker.
   Single-molecule studies of nucleic acid motors (Review)
   Current Opinion in Structural Biology 17(1) 80-86 (2007)  PDF
   
   
3. L.K. Stanley*, R. Seidel*, C. van der Scheer, N.H. Dekker, M.D. Szczelkun & C. Dekker.
   When a helicase is not a helicase: dsDNA tracking by the motor protein EcoR124I
   EMBO Journal 25(10) 2230-2239 (2006)  PDF   Suppl. data   The EMBO Journal
   *shared first authorship
   
   
4. R. Seidel, J.G.P. Bloom, J. van Noort, C.F. Dutta, N.H. Dekker, K. Firman_, M.D. Szczelkun & C. Dekker. Dynamics of initiation, termination and reinitiation of DNA translocation by the motor protein EcoR124I. EMBO Journal 24(23), 4188-4197 (2005)  PDF   Suppl. data   The EMBO Journal
   
   
5. R. Seidel, J. van Noort, C. van der Scheer, J.G.P. Bloom, N.H. Dekker, C.F. Dutta, A. Blundell, T. Robinson, K. Firman & C. Dekker,
   Real-time observation of DNA translocation by the type I restriction modification enzyme EcoR124I
   Nature Structural & Molecular Biology 11(9), 838-843 (2004)  PDF    Niews & Views

Full Publication List

Our group is funded by the Emmy-Noether program of the Deutsche Forschungsgemeinschaft (DFG)

All current group members are listed on the Staff Page.