Mechanics of Ribosomal TranslocationWhen: Thursday, April 11, 2013 at 4:00 pm
Where: DA 114
Speaker: Dmitri Ermolenko
Organization: University of Rochester Medical Center
Sponsor: Physics Colloquium
“The ribosome plays a central role in cell physiology by translating genetic information into proteins in all living organisms. It remains one of the most intriguing of all biological structures because of its size and structural complexity. During protein synthesis, mRNA and tRNAs are moved through the ribosome by the dynamic process of translocation, which is induced by a protein named elongation factor G (EF-G) in bacteria or by its eukaryotic homologue EF-2. The mechanism of ribosomal translocation is still poorly understood. We use single-molecule fluorescent microscopy and biochemical approaches to elucidate the mechanics of ribosomal translocation.
The Brownian ratchet and the power stoke mechanisms are the two main theoretical models describing movements of molecular machines. In Brownian ratchet models, unidirectional movement of macromolecules is enabled by ligand binding and chemical reactions which lock them in a preferred state, thereby rectifying their spontaneous fluctuations. In power stroke models, the movement occurs through the transition from a high-energy, “cocked” state into a more stable, “relaxed” conformation of macromolecule machine, i.e. through the power stroke. In this talk, I will apply the conceptual framework of the Brownian ratchet and the power stroke mechanisms in order to explain our experimental data and the mechanism of ribosomal translocation.”
Host: Assistant Paul Whitford