Biosensor for branched-chain amino acid metabolism in yeast and applications in isobutanol and isopentanol production

• Published in: Nature communications Vol. 13; no. 1; p. 270
• Main Authors: Zhang, Yanfei, Cortez, Jeremy D., Hammer, Sarah K., Carrasco-López, César, García Echauri, Sergio Á., Wiggins, Jessica B., Wang, Wei, Avalos, José L.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 12.01.2022; Nature Publishing Group; Nature Portfolio
• Subjects: 13; 140/58; 2-Isopropylmalate Synthase - genetics; 2-Isopropylmalate Synthase - metabolism; 49; 49/31; 631/553/552; 631/61/318; 9/10; Alcohol; Amino acids; Amino Acids, Branched-Chain - metabolism; Biodegradation; Biosensing Techniques; Biosensors; Biosynthesis; Biosynthetic Pathways; Butanols - metabolism; Chain branching; Chains; Configurations; Cytosol; Ethanol - metabolism; Genetic code; High-Throughput Screening Assays; Humanities and Social Sciences; Isobutanol; Isopentyl alcohol; Leucine; Leucine - metabolism; Metabolic Engineering; Metabolism; Mitochondria; multidisciplinary; Pentanols - metabolism; Saccharomyces cerevisiae - metabolism; Saccharomyces cerevisiae Proteins - genetics; Saccharomyces cerevisiae Proteins - metabolism; Science; Science (multidisciplinary); Screens; Synthetic Biology; Transcription; Valine; Yeast; Yeasts
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-021-27852-x

Branched-chain amino acid (BCAA) metabolism fulfills numerous physiological roles and can be harnessed to produce valuable chemicals. However, the lack of eukaryotic biosensors specific for BCAA-derived products has limited the ability to develop high-throughput screens for strain engineering and metabolic studies. Here, we harness the transcriptional regulator Leu3p from Saccharomyces cerevisiae to develop a genetically encoded biosensor for BCAA metabolism. In one configuration, we use the biosensor to monitor yeast production of isobutanol, an alcohol derived from valine degradation. Small modifications allow us to redeploy Leu3p in another biosensor configuration that monitors production of the leucine-derived alcohol, isopentanol. These biosensor configurations are effective at isolating high-producing strains and identifying enzymes with enhanced activity from screens for branched-chain higher alcohol (BCHA) biosynthesis in mitochondria as well as cytosol. Furthermore, this biosensor has the potential to assist in metabolic studies involving BCAA pathways, and offers a blueprint to develop biosensors for other products derived from BCAA metabolism. There are a lack of eukaryotic biosensors specific for branched-chain amino acid (BCAA)-derived products. Here the authors report a genetically encoded biosensor for BCAA metabolism based on the Leu3p transcriptional regulator; they use this to monitor yeast production of isobutanol and isopentanol.