February 2, Mon 2015
3:30 pm, Adams Alumni Center, Bruckmiller Room
Dr. Charles Brooks
Warner-Lambert/Parke-Davis Professor of Chemistry and Biophysics, Department of Chemistry and Biophysics, University of Michigan
Understanding Robustness in Biology’s Molecular Machines
Biological machines are required to perform many aspects of their mechanical function in the background of species variation, mutations and alterations of their underlying chemical make-up that lead to alternative protein and nucleic acid sequences. How does this happen? Where and how does biology achieve the robustness that is essential for achieving similar function across these variations? In this lecture we will explore the nature of structure-function relationships used in a range of biological machines, from ribosomes, as the key machinery of protein synthesis in the cell, to helicases that function in transcription of DNA to RNA, to viral capsid assembly. In each of these systems, we will suggest that these biological machines utilize simple physical principles as constraints that operate on a scale that is largely ignorant of the detailed nature of the chemical make-up of their constituent components. We will illustrate how the key motions necessary for critical steps in protein synthesis by the ribosome and in functional motions that unwind double-stranded DNA as part of the process of transcription rely largely on the architecture and shape of the these macromolecular machines. We will also demonstrate how elements of viral assembly and the composition of virus types can be rationalized from simple considerations of geometry and topology.