Biosynthesis of Taxadiene in Saccharomyces cerevisiae : selection of geranylgeranyl diphosphate synthase directed by a computer-aided docking strategy

PLoS One. 2014 Oct 8;9(10):e109348. doi: 10.1371/journal.pone.0109348. eCollection 2014.

Abstract

Identification of efficient key enzymes in biosynthesis pathway and optimization of the fitness between functional modules and chassis are important for improving the production of target compounds. In this study, the taxadiene biosynthesis pathway was firstly constructed in yeast by transforming ts gene and overexpressing erg20 and thmgr. Then, the catalytic capabilities of six different geranylgeranyl diphosphate synthases (GGPPS), the key enzyme in mevalonic acid (MVA) pathway catalyzing famesyl diphosphate (FPP) to geranylgeranyl diphosphate (GGPP), were predicted using enzyme-substrate docking strategy. GGPPSs from Taxus baccata x Taxus cuspidate (GGPPSbc), Erwinia herbicola (GGPPSeh), and S. cerevisiae (GGPPSsc) which ranked 1st, 4th and 6th in docking with FPP were selected for construction. The experimental results were consistent with the computer prediction that the engineered yeast with GGPPSbc exhibited the highest production. In addition, two chassis YSG50 and W303-1A were chosen, and the titer of taxadiene reached 72.8 mg/L in chassis YSG50 with GGPPSbc. Metabolomic study revealed that the contents of tricarboxylic acid cycle (TCA) intermediates and their precursor amino acids in chassis YSG50 was lower than those in W303-1A, indicating less carbon flux was divided into TCA cycle. Furthermore, the levels of TCA intermediates in the taxadiene producing yeasts were lower than those in chassis YSG50. Thus, it may result in more carbon flux in MVA pathway in chassis YSG50, which suggested that YSG50 was more suitable for engineering the taxadiene producing yeast. These results indicated that computer-aided protein modeling directed isoenzyme selection strategy and metabolomic study could guide the rational design of terpenes biosynthetic cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkenes / metabolism*
  • Diterpenes / metabolism*
  • Polyisoprenyl Phosphates / metabolism
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins / metabolism*

Substances

  • Alkenes
  • Diterpenes
  • Polyisoprenyl Phosphates
  • Saccharomyces cerevisiae Proteins
  • taxa-4(5),11(12)diene
  • geranylgeranyl pyrophosphate

Grants and funding

This work was funded by the Ministry of Science and Technology of China ("863" Program: 2012AA02A701 and "973" Program: 2012CB721105). The authors also thank Huimin Zhao of University of Illinois at Urbana-Champaign for kindly providing yeast YSG50. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.