Redirection of pyruvate flux toward desired metabolic pathways through substrate channeling between pyruvate kinase and pyruvate-converting enzymes in Saccharomyces cerevisiae

Sci Rep. 2016 Apr 7:6:24145. doi: 10.1038/srep24145.

Abstract

Spatial organization of metabolic enzymes allows substrate channeling, which accelerates processing of intermediates. Here, we investigated the effect of substrate channeling on the flux partitioning at a metabolic branch point, focusing on pyruvate metabolism in Saccharomyces cerevisiae. As a platform strain for the channeling of pyruvate flux, PYK1-Coh-Myc strain was constructed in which PYK1 gene encoding pyruvate kinase is tagged with cohesin domain. By using high-affinity cohesin-dockerin interaction, the pyruvate-forming enzyme Pyk1 was tethered to heterologous pyruvate-converting enzymes, lactate dehydrogenase and α-acetolactate synthase, to produce lactic acid and 2,3-butanediol, respectively. Pyruvate flux was successfully redirected toward desired pathways, with a concomitant decrease in ethanol production even without genetic attenuation of the ethanol-producing pathway. This pyruvate channeling strategy led to an improvement of 2,3-butanediol production by 38%, while showing a limitation in improving lactic acid production due to a reduced activity of lactate dehydrogenase by dockerin tagging.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetolactate Synthase / genetics
  • Acetolactate Synthase / metabolism*
  • Butylene Glycols / metabolism
  • Cell Cycle Proteins / metabolism
  • Chromosomal Proteins, Non-Histone / metabolism
  • Cohesins
  • Ethanol / metabolism
  • L-Lactate Dehydrogenase / genetics
  • L-Lactate Dehydrogenase / metabolism*
  • Lactic Acid / metabolism
  • Metabolic Engineering / methods
  • Metabolic Networks and Pathways* / genetics
  • Pyruvate Kinase / genetics
  • Pyruvate Kinase / metabolism*
  • Pyruvates / metabolism*
  • Reproducibility of Results
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Substrate Specificity

Substances

  • Butylene Glycols
  • Cell Cycle Proteins
  • Chromosomal Proteins, Non-Histone
  • Pyruvates
  • Saccharomyces cerevisiae Proteins
  • Lactic Acid
  • Ethanol
  • 2,3-butylene glycol
  • L-Lactate Dehydrogenase
  • Acetolactate Synthase
  • Pyruvate Kinase