(423b) Coordinated Induction of Multi-Gene Pathways in Saccharomyces Cerevisiae

Bacterial operon has been an important tool in regulating and coordinating multi-gene expression in prokaryotes. It is also a gene architecture commonly employed in the biosynthesis of many pharmaceutically important compounds and industrially usefully chemicals. Despite being an important eukaryotic production host, S. cerevisiae never had such gene architecture. Here, we report the development of a system to assemble a multi-gene pathway into an operon-like structure using pre-made parts from a plasmid toolbox. Subsequently, through the use of a yeast strain containing a stably integrated gene switch, we can regulate the assembled pathway using a readily available compound – estradiol – with extremely high sensitivity. To demonstrate the utility of the system, we assembled the 5-gene zeaxanthin biosynthetic pathway in a single step and showed the ligand dependent, coordinated expression of all 5 genes as well as the tightly-regulated production of zeaxanthin. Using a previously reported constitutive zeaxanthin pathway as a benchmark, our inducible pathway is shown to have 50-fold higher production level.