DNA Microtubules: a physical approach to synthetic biology – Deborah Fygenson

Date: Thu. April 27th, 2006, 4:15 pm-5:15 pm
Location: Rockefeller 301

Microtubules are self-assembling/self-destructing tubular crystals of the protein tubulin that underpin the structure of most cells. Their dramatic dynamic instability has generated interest among biologists and physicists alike since its discovery in 1984, but still awaits a physical explanation. One reason is that tubulin is not amenable to the powerful expression and mutagenesis techniques of molecular biology. Another is that dynamic instability has no analog among non-biological materials. In this talk I will describe our approach to overcoming these challenges via “synthetic biology”. Briefly, we have developed a set of short sequences of DNA that use Watson-Crick base-pairing to self-assemble into tubular crystals which bear analogy to microtubules. We can adjust the DNA sequences to generate well-defined physical perturbations and measure the consequences both in bulk and under the microscope. In this manner, we aim to eventually reconstruct key features of microtubules and gain insight into the physical origins of dynamic instability. I will describe our recent progress in understanding and manipulating various aspects of the structure, assembly and overall stability of these abiological “DNA microtubules”.