Physics Colloquium - Friday, Dec. 1st, 2006, 4:00 P.M.

E300 Math/Science Center; Refreshments at 3:30 P.M. in Room E200

Meredith Betterton
University of Colorado

Motor protein interaction with obstacles and helicase unwinding of DNA

Molecular motors are small machines that move and do work in cells. These motor proteins are required for many important biological processes and are of interest as prototypes of nanoscale machines. This talk will describe a theory of motor proteins that move obstacles, using the unwinding of double-stranded DNA molecules by helicase proteins as an example. The results predict how the coupling between translocation and unwinding affects the unwinding velocity and processivity of a helicase, as well as collective effects which occur when multiple helicases unwind DNA. We compare the predictions to experimental results, including dependence on the interaction potential, helicase step size, and average base-pair binding free energy.