Dave Savage - Fixed: Systems and synthetic biological approaches for understanding photosynthetic CO2 fixation

Cells usestructure to catalyze and facilitate the chemical reactions of metabolism. Thisprinciple is exemplified by the process of carbon dioxide assimilation inphotosynthetic cyanobacteria, which coordinate myriad biochemical components inspace and time, in order to achieve a single physiological goal – convert solarpower into fixed chemical energy. An essential player in this process is thecarboxysome, a protein-based organelle composed of an icosahedral proteinshell, which encapsulates the enzymes RuBisCO and carbon anhydrase within a~100 nm structure. Despite knowledge of the overall structure of thecarboxysome, much less is known about the molecular interactions driving itsself-assembly and how this process is capable of occurring in the complex invivo environment. Here, I describe our biochemical efforts to elucidate amechanistic picture of how the carboxysome assembles and functions in the cell.At the same time, our lab is also interested in developing a holistic pictureof how a coordinated physiology emerges from the many different proteinactivities, including the carboxysome and numerous transporters, found incyanobacteria. To this end, I present our recent efforts at reconciling theseactivities using a mathematical reaction-diffusion model of carbon dioxideassimilation. Finally, a general challenge to studying physiology is the lowthroughput of assays for quantifying metabolism. I therefore conclude with ourefforts at using protein engineering for constructing fluorescent metabolitebiosensors and enabling high-throughput studies of metabolism.