Friday, October 29, 2004
DNA Topology: Experiments and Analysis
De Witt Sumners
Robert O. Lawton Professor and Chair
Department of Mathematics
Florida State University
Cellular DNA is a long, thread-like molecule with remarkably complex topology. Enzymes which manipulate the geometry and topology of cellular DNA perform many important cellular processes (including segregation of daughter chromosomes, gene regulation, DNA repair, and generation of antibody diversity). Some enzymes pass DNA through itself via enzyme-bridged transient breaks in the DNA; other enzymes break the DNA apart and reconnect it to different ends. In the topological approach to enzymology, circular DNA is incubated with an enzyme, producing an enzyme signature in the form of DNA knots and links. By observing the changes in DNA geometry (supercoiling) and topology (knotting and linking) due to enzyme action, the enzyme binding and mechanism can often be characterized. This talk will discuss topological models for DNA strand passage and exchange in site-specific DNA recombination, and use of the spectrum of DNA knots to infer bacteriophage DNA packing in viral capsids.
Friday, September 3, 2004
Information for this presentation is not available.