The ability to optimize pathway flux is one of the most important factors toward maximizing product titers. The traditional approaches largely focused on the overexpression of rate-limiting enzymes, competing pathway deletion, and resource management. However, most of these approaches are static in nature and do not provide dynamic regulation of pathway fluxes based on substrate, precursor, and product availability. Although many genetic circuit designs have been implemented to provide dynamic control of gene expression and pathway fluxes, these dynamic strategies usually provide only excellent “up-regulation” control but down regulation is much slower as it requires the degradation of the associated regulatory components. In this proposal, we seek to investigate a new transformative strategies that provide faster on-and-off control based on enzyme proximity control inspired by natural dynamic metabolons. The goal to develop synthetic dynamic metabolons that will allow carbon flux to be redirected at will. The end result is the ability to provide dynamic optimization of microbial metabolism for optimal product formation. This will be achieved by the dynamic shifts between the assembly and disassembly of synthetic metabolons in order modulate the overall output function. Nature has already based on the use of RNA scaffold. The central framework is to design RNA- or protein-based dynamic metabolons that assemble in response to specific metabolic demands and to exploit the dynamic shift between the assembly and disassembly of enzyme complexes to coordinate metabolic pathways for optimal product titer. The tools developed here could be transferred to other organisms, and used to address fundamental questions about control and regulation of metabolism.
Project 1. Synthetic Control of Metabolism by Dynamic Metabolons (NSF)
