title: Bypassing the Pentose Phosphate Pathway: Towards Modular Utilization of Xylose.
abstract: The efficient use of hemicellulose in the plant cell wall is critical for the economic conversion of plant biomass to renewable fuels and chemicals. Previously, the yeast Saccharomyces cerevisiae has been engineered to convert the hemicellulose-derived pentose sugars xylose and arabinose to d-xylulose-5-phosphate for conversion via the pentose phosphate pathway (PPP). However, efficient pentose utilization requires PPP optimization and may interfere with its roles in NADPH and pentose production. Here, we developed an alternative xylose utilization pathway that largely bypasses the PPP. In the new pathway, d-xylulose is converted to d-xylulose-1-phosphate, a novel metabolite to S. cerevisiae, which is then cleaved to glycolaldehyde and dihydroxyacetone phosphate. This synthetic pathway served as a platform for the biosynthesis of ethanol and ethylene glycol. The use of d-xylulose-1-phosphate as an entry point for xylose metabolism opens the way for optimizing chemical conversion of pentose sugars in S. cerevisiae in a modular fashion.
authors.affiliation: Department of Plant and Microbial Biology, University of California, Berkeley, CA, United States of America.
authors.forename: Kulika
authors.initials: K
authors.lastname: Chomvong
authors.affiliation: Energy Biosciences Institute, Berkeley, CA, United States of America.
authors.forename: Stefan
authors.initials: S
authors.lastname: Bauer
authors.affiliation: Program in Metabolic Biology, Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA, United States of America.
authors.forename: Daniel I
authors.initials: DI
authors.lastname: Benjamin
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, CA, United States of America.
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.affiliation: Program in Metabolic Biology, Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA, United States of America.
authors.forename: Daniel K
authors.initials: DK
authors.lastname: Nomura
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, CA, United States of America.|Department of Chemistry, University of California, Berkeley, CA, United States of America.|Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States of America.
authors.forename: Jamie H D
authors.initials: JH
authors.lastname: Cate
mesh_terms: D005285:Fermentation; D015971:Gene Expression Regulation, Enzymologic; D015966:Gene Expression Regulation, Fungal; D053858:Metabolic Networks and Pathways; D009154:Mutation; D010427:Pentose Phosphate Pathway; D010429:Pentoses / Q000378:metabolism*; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D014994:Xylose / Q000378:metabolism*
chemical_list: D010429:Pentoses; D014994:Xylose; D017853:Phosphotransferases (Alcohol Group Acceptor)