Mara Prentiss, Physics Department, Harvard

Topic: "Solving the Mysteries of Life with Single Molecule Biophysics"  (Video)

ABSTRACT: DNA reproduction and repair play essential roles in all living organisms, but many mysteries about the underlying mechanisms remain mysterious. Recent work has shown that basic physical properties of DNA play important roles in these processes, opening up new theoretical and experimental opportunities for physicists. For example, in order to reproduce, chromosomes must pair. Thus, like chromosomes must find each other and align in sufficiently close proximity that they can exchange basepairing. This must occur despite the strong negative charge on the DNA. Previously, it had been assumed that proteins solved this problem, but recent work has shown that in the absence of proteins long double stranded DNA sequences can efficiently find and join with a sequence matched partner even in the midst of far more prevalent non-sequence matched competitors. Finally, very new results suggest that even processes that involve proteins may be governed by the physical properties of the DNA rather than by the activity of the protein itself. These results also suggest new generalized principles for optimizing the self-assembly of natural and artificial nanostructures.