Overexpressing 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) in the lactococcal mevalonate pathway for heterologous plant sesquiterpene production

PLoS One. 2012;7(12):e52444. doi: 10.1371/journal.pone.0052444. Epub 2012 Dec 26.

Abstract

Isoprenoids are a large and diverse group of metabolites with interesting properties such as flavour, fragrance and therapeutic properties. They are produced via two pathways, the mevalonate pathway or the 2-C-methyl-D-erythritol-4-phosphate (MEP) pathway. While plants are the richest source of isoprenoids, they are not the most efficient producers. Escherichia coli and yeasts have been extensively studied as heterologous hosts for plant isoprenoids production. In the current study, we describe the usage of the food grade Lactococcus lactis as a potential heterologous host for the production of sesquiterpenes from a local herbaceous Malaysian plant, Persicaria minor (synonym Polygonum minus). A sesquiterpene synthase gene from P. minor was successfully cloned and expressed in L. lactis. The expressed protein was identified to be a β-sesquiphellandrene synthase as it was demonstrated to be functional in producing β-sesquiphellandrene at 85.4% of the total sesquiterpenes produced based on in vitro enzymatic assays. The recombinant L. lactis strain developed in this study was also capable of producing β-sesquiphellandrene in vivo without exogenous substrates supplementation. In addition, overexpression of the strain's endogenous 3-hydroxy-3-methylglutaryl coenzyme-A reductase (HMGR), an established rate-limiting enzyme in the eukaryotic mevalonate pathway, increased the production level of β-sesquiphellandrene by 1.25-1.60 fold. The highest amount achieved was 33 nM at 2 h post-induction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkyl and Aryl Transferases / biosynthesis
  • Alkyl and Aryl Transferases / genetics
  • Cloning, Molecular
  • Gene Expression
  • Hydroxymethylglutaryl CoA Reductases / biosynthesis
  • Hydroxymethylglutaryl CoA Reductases / genetics*
  • Lactococcus lactis / genetics*
  • Lactococcus lactis / metabolism*
  • Metabolic Engineering / methods*
  • Mevalonic Acid / metabolism*
  • Plasmids / genetics
  • Polygonaceae / enzymology
  • Polygonaceae / genetics*
  • Recombinant Proteins / biosynthesis
  • Recombinant Proteins / genetics
  • Sesquiterpenes / metabolism*

Substances

  • Recombinant Proteins
  • Sesquiterpenes
  • Hydroxymethylglutaryl CoA Reductases
  • Alkyl and Aryl Transferases
  • terpene synthase
  • Mevalonic Acid

Grants and funding

This work was supported by “The Genomics and Molecular Biology Initiative of the Malaysia Genome Institute, Ministry of Science, Technology and Innovation, Malaysia (MOSTI) (07-05-MGI-GMB 004)” and National Science Fellowship, MOSTI. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.