(422d) Design and Synthesis of RNA Thermoregulators to Optimize Production of Essential Metabolites and Therapeutic Molecules in Bioprocesses

Bioprocesses nowadays are used to manufacture a wide variety of chemical compounds including polymers, biofuels, and therapeutic molecules. In order to increase the yield of these valuable metabolites, strategies like overexpression and deletion of the involved genes have been implemented. Nevertheless, some of these genes have been found to be responsible for bacterial growth and other essential cell functions, therefore the deletion of these genes would result in more desired product yield per cell but a decreased cell density, and in many cases the result will be cell death. Using genetic switches can be an alternative approach to keep the expression of the involved genes controlled. In this way, the production of the interest metabolite or bacterial growth could be regulated by the metabolic flux. One interesting approach that has been explored in this work is the use of RNA thermoregulators, which are translational controllers of gene expression that respond to temperature shifts by changing their conformational structure. At low temperature, they acquire a secondary structure that precludes the binding of ribosomes to the Shine-Dalgarno (SD) sequence; preventing mRNA translation. Moreover, when temperature increases, RNA thermoregulators reconfigure their conformation, allowing the binding of ribosomes to the SD sequence––which in turn initiates mRNA translation.

Although naturally-occurring RNA thermoregulators are associated with diverse biological processes (e.g. bacterial pathogenesis and life cycle of some bacteriophages), many synthetic analogs have been designed and characterized, for optimal control of gene expression in vivo. In this work, we designed and synthesized different families of synthetic RNA thermoregulators that serve as genetic switches to control different pathways, in Escherichia coli, involved in the production of essential metabolites and molecules with therapeutic properties. This work describes a novel platform technology capable of controlling metabolic flux via RNA thermoregulation in vivo for the production of great value metabolites.