Single Molecule Studies of DNA Replication
and Polymer Physics

Charles Schroeder
Harvard University

Date: Thursday Feb. 2, 2006
Time: 4:00 p.m.
Place: Engineering II, Room 3361

ABSTRACT

Single molecule techniques offer a powerful approach to investigate complex physical and biological processes. In this work, we study DNA replication by direct observation of the enzymatic behavior of single DNA polymerase molecules on nucleic acid template strands in vitro. A flow-stretched DNA assay allows for characterization of enzymatic rate, processivity, and pausing during DNA synthesis as a function of base pair content. We study strand displacement and primer extension DNA synthesis by bacteriophage Phi29 polymerase and leading strand DNA synthesis via the multi-protein replisome of bacteriophage T4. In addition to biological systems, we also present two topics in polymer physics: polymer conformation hysteresis and characteristic periodic motion in shear flow. Characterization of physical phenomena such as polymer chain hysteresis and periodic dynamical motion is greatly facilitated by observation of single molecules.