Characterizing Conformational Fluctuations of DNA
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Date
2021
Authors
Chang, Anabel
Journal Title
Journal ISSN
Volume Title
Publisher
University of Oregon
Abstract
The Marcus Group uses fluorescence spectroscopy to study the dynamics of macromolecules and molecular systems in biological environments. In this project we perform single molecule measurements on double-stranded (ds) DNA to determine the number of conformational macrostates and the timescale of their interconversion; can we characterize the free energy landscape governing single-stranded (ss)-ds DNA junctions? We are interested in the local conformational fluctuations of dsDNA molecules, or DNA breathing. Base pairs are broken and exposed to the environment during breathing events, which allows proteins to access and bind the ssDNA. DNA breathing fluctuations affect the assembly and functional activity of macromolecular machines, which are enzyme complexes with active sites performing life-essential tasks like ATP synthesis. The Marcus Group uses a variety of spectroscopic methods to study the conformations and fluctuations of DNA breathing. This project labels single DNA molecules with fluorescent optical probes, and uses rotating polarization techniques to study the dynamics of the molecule using time correlated single photon counting. Studies are ongoing, but have resulted in a better understanding of DNA breathing conformational states and their transition rates. Further characterization and analysis of these thermal fluctuations using time correlation functions and kinetic modeling will help create a mechanistic picture of DNA breathing.
Description
1 page.
Keywords
DNA, fluctuations, spectroscopy, dynamics, conformation