Design and engineering of intracellular‐metabolite‐sensing/regulation gene circuits in Saccharomyces cerevisiae

ABSTRACT The development of high‐throughput phenotyping tools is lagging far behind the rapid advances of genotype generation methods. To bridge this gap, we report a new strategy for design, construction, and fine‐tuning of intracellular‐metabolite‐sensing/regulation gene circuits by repurposing bacterial transcription factors and eukaryotic promoters. As proof of concept, we systematically investigated the design and engineering of bacterial repressor‐based xylose‐sensing/regulation gene circuits in Saccharomyces cerevisiae . We demonstrated that numerous properties, such as induction ratio and dose–response curve, can be fine‐tuned at three different nodes, including repressor expression level, operator position, and operator sequence. By applying these gene circuits, we developed a cell sorting based, rapid and robust high‐throughput screening method for xylose transporter engineering and obtained a sugar transporter HXT14 mutant with 6.5‐fold improvement in xylose transportation capacity. This strategy should be generally applicable and highly useful for evolutionary engineering of proteins, pathways, and genomes in S. cerevisiae . Biotechnol. Bioeng. 2016;113: 206–215. © 2015 Wiley Periodicals, Inc.