Department of Chemistry and Biochemistry
Physical Chemistry Seminar Series

Professor Andrew H. Marcus, University of Oregon 

Studies of local DNA structure and dynamics by nonlinear spectroscopy and single-molecule optical approaches

DNA contains the ‘genetic information’ that is encoded as specific DNA base sequences, and which is ‘read’ and ‘processed’ by proteins that interact with DNA at specific sites. The local conformations of DNA bases and sugar-phosphate backbones near single-stranded (ss) – double-stranded (ds) DNA junctions undergo thermally activated fluctuations (termed DNA ‘breathing’) within an unknown distribution of macrostates to permit the proper binding of proteins involved in core biochemical processes. In this talk, I will discuss novel spectroscopic methods and analyses – both at the ensemble and single-molecule levels – to study structural and dynamic properties of exciton-coupled molecular dimer-labeled DNA constructs in which the dimer probes are inserted at key positions involved in protein-DNA complex assembly and function. The exciton-coupled dimer probes act as ‘sensors’ of the local conformations adopted by the DNA bases and backbones immediately adjacent to the probes. These methods can be used to study the biochemical mechanisms of protein-DNA recognition, complex assembly, and function in biological processes.