INTELLECTUAL MERIT: Chromosomes of all living cells are folded into a highly ordered structure with multilevel organization to fit within a confined space. To support cellular functions, chromosome structure undergoes a variety of changes both on the global and local levels. Understanding global chromatin organization is particularly challenging because it requires explaining how chromosomal proteins control the structure of the much bigger chromosome. This project focuses on the mechanism of proteins called condensins and cohesins, which play a central role in global packing of the chromosomes in organisms ranging from bacteria to humans. In this project, the mechanism of DNA organization by several such protein complexes, including the bacterial condensin named MukBEF and the eukaryotic condensins and cohesins, will be explored. The project involves the use of several complementary techniques that assess DNA reconfiguration in vitro, in live cells, and on a single DNA molecule and includes the development of methods suitable for biochemical dissection of the higher order chromatin structure. The completion of this study will uncover the mechanism of chromatin rearrangements by condensins and cohesins and will increase our ability to manipulate chromatin structure. BROADER IMPACT: The broader impact of this project includes the establishment of a nanomanipulations research center specializing in problems at the interface of physics, chemistry and biology as well as integrated interdisciplinary education on graduate and undergraduate levels. The magnetic tweezers, a technology that allows for analysis of DNA configuration at the level of a single molecule, and its focus on biological problems will be synergistic to the existing and emerging nanotechnology research within the Oklahoma NanoNet. The educational component includes the exposure of graduate and undergraduate students to single molecule research on self-organizing systems and the development of new courses in biophysical chemistry both on graduate and undergraduate levels.
