Physical/Theoretical Chemistry Seminar: Professor Aaron Frank, University of Michigan (Host: Laura Dassama)
About the Seminar
"Using Statistical Mechanics to Model Dynamical Ensembles of Ribonucleic Acids"
RNAs are notoriously flexible biomolecules, requiring an ensemble representation of their structure. Constructing such dynamical ensembles, which comprise the set of conformations an RNA can adopt, along with their associated populations, is challenging because biophysical measurements only indirectly report on the properties of the underlying conformational (Boltzmann) distribution. In this talk, I will describe how we use statistical mechanics to model the dynamical ensembles of RNA using local solvent accessibility data. My talk will culminate with a description of how we used experimentally-derived solvent accessibility information to construct a pair of atomistic ensembles of the aptamer domain of the S-adenosylmethionine (SAM) class-I riboswitch. The differences we observed in the resulting -SAM and +SAM ensembles are consistent with a SAM-dependent reshaping of the aptamer's dynamical landscape. Interestingly, within our -SAM ensemble, we observed a transient conformational state that may be a folding intermediate and which harbors a hidden binding pocket that we predict can selectively recognize small-molecule ligands.
About the Speaker
Aaron Frank is originally from Grenada, a small island in the Caribbean. After moving to the US in 2001, Aaron received his BA in chemistry from Brooklyn College in 2006. There he carried out research in the groups of Professors Charlene Forest, Shaneen Singh, and Alexander Greer. He then moved to Michigan to attend graduate school at the University of Michigan and then, with his Ph.D. advisor Professor Ioan Andricioaei, moved to UC Irvine in 2008. Aaron received his Ph.D. in chemistry in 2011. Following a two-year stint at Nymirum Inc. — a small biotech company in Ann Arbor founded by a close collaborator, Professor Hashimi Al-Hashimi — he returned to the University of Michigan as a Presidential Postdoctoral Fellow where he was mentored by Professor Charles L. Brooks, III. Aaron is now an Assistant Professor at the University of Michigan in the Biophysics Department. His research group uses integrative modeling to elucidate structure-function relationships in RNA and guide the discovery and design of RNA-targeting small molecules.
Photo by Scott Soderberg, Michigan Photography, University of Michigan.