CAREER: Investigation of DNA-binding Protein Dynamics With High-resolution Optical Traps

University Of Illinois At Urbana-Champaign, Urbana IL

Investigators

Abstract

A broad class of DNA-binding protein interacts with the genome in a non-sequence-specific manner. These proteins act mechanically on their substrates, altering DNA conformation by bending, twisting, or stretching the molecule, and oligomerizing to form long filaments. These nucleoprotein complexes often serve as substrates upon which genome maintenance processes occur. Thus, they are involved in all aspects of DNA metabolism, in replication, recombination, and repair, and are important regulators of cellular processes. Single-stranded DNA binding proteins (SSB) serve as a model system for features common to this class of proteins. This project will use a synthesis of techniques from traditional biochemistry and molecular biology, in combination with single-molecule biophysics and computational biology to investigate: (1) how SSBs induce conformational rearrangement of nucleic acids, (2) how they oligomerize into nucleoprotein filaments, and (3) how these protein clusters recruit and modulate the activity of other proteins involved in nucleic acid processing. Specifically, high-resolution optical trapping in combination with single-molecule fluorescence techniques will be used to reveal dynamic protein-DNA interactions, going beyond the limitations of current methods. This work will shed light on fundamental aspects of genome maintenance. Broader impact: The PI has a deep commitment to interdisciplinary education of young scientists and outreach towards underrepresented groups. In particular, he sees in biophysics a unique opportunity to recruit women, who have traditionally been drawn to biology over physics, into the quantitative sciences. The outreach and education components of the project synthesize these themes into a broad plan targeting middle and high school, undergraduate, and graduate education. Specifically, the PI will: (1) develop a lab camp for a girls' summer program to teach middle and high school girls about physics and its impact on biological problems and to provide hands-on experience with biophysics, (2) improve the teaching of an introductory undergraduate physics course for life science students (the majority of whom are women) to better connect physics concepts with biology and medicine, (3) develop a lab course devoted to the training of the next generation of biophysicists in advanced technologies as part of the NSF Center for the Physics of the Living Cells (CPLC), and (4) participate in yearly minority conferences. This project is jointly supported by the Genes and Genome Systems Cluster and the Biomolecular Systems Cluster in the Division of Molecular and Cellular Biosciences.