The 1998 Marden Lecture

Mathematical Sciences
University of Wisconsin-Milwaukee

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This year's Marden Lecture will be held on Thursday, April 9, 1998, at 3:00 pm in room N140 of the Business Building on the campus of the University of Wisconsin-Milwaukee.
Look here for some campus maps.

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THE TOPOLOGY OF DNA

Professor De Witt Sumners
Department of Mathematics
Florida State University

Prof. Sumners received his B.Sc. in physics from Louisiana State University (1963) and his Ph.D. in mathematics from the University of Cambridge, England (1967). In 1967 he joined the Department of Mathematics at Florida State University. In 1993 he was named Distinguished Research Professor, and in 1997, the Robert O. Lawton Distinguished Professor. Since 1990 he has been a member of the Institute of Molecular Biophysics at FSU. Since 1995 he has been a co-director of the Program in Mathematics and Molecular Biology, a multidisciplinary, multi-university program including faculty from FSU, the University of California at Berkeley, and several other universities. Prof. Sumners has received numerous awards both in the US and abroad, and his work has been recognized worldwide.

Abstract of talk

Cellular DNA is a long, thread-like molecule with remarkably complex topology. Many important cellular processes (including segregation of daughter chromosomes, gene regulation, DNA repair, and generation of antibody diversity) are performed by enzymes which manipulate the geometry and topology of cellular DNA. 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 expository lecture will discuss topological models for the structure of DNA and the active enzyme-DNA complex.

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This program is free and open to the public. A reception will follow in room E495A of the EMS Building.
The lecture is supported by the Morris and Miriam Marden Fund and is co-sponsored by the Department of Mathematical Sciences. For more information, contact Malgorzata Klosek at 229-4863 or mklosek@uwm.edu.

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