Cloning and Characterization of a cDNA Encoding Beta-Amyrin Synthase From Petroleum Plant Euphorbia Tirucalli L

Phytochemistry. 2005 Aug;66(15):1759-66. doi: 10.1016/j.phytochem.2005.05.021.


Euphorbia tirucalli L., known as the petroleum plant, produces a large amount of triterpenes, such as beta-amyrin. Degenerate RT-PCR based on the sequences conserved among known beta-amyrin synthases led to cloning of a putative triterpene synthase cDNA, EtAS, from leaves of E. tirucalli. The deduced amino acid sequence of the EtAS cDNA showed the highest identity of 82% to the Panax ginseng beta-amyrin synthase. Heterologous expression of the EtAS ORF in the methylotrophic yeast, Pichia pastoris, resulted in production of beta-amyrin, revealing that the EtAS cDNA codes for a beta-amyrin synthase. This is the first report of a gene involved in the triterpene synthetic pathway from Euphorbiaceae plants.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Cloning, Molecular
  • Conserved Sequence
  • DNA, Complementary
  • Euphorbia / enzymology*
  • Euphorbia / genetics
  • Gas Chromatography-Mass Spectrometry
  • Intramolecular Transferases / chemistry
  • Intramolecular Transferases / genetics*
  • Intramolecular Transferases / metabolism
  • Molecular Sequence Data
  • Recombinant Proteins / metabolism
  • Sequence Alignment
  • Sequence Homology, Amino Acid


  • DNA, Complementary
  • Recombinant Proteins
  • Intramolecular Transferases
  • 2,3-oxidosqualene-beta-amyrin-cyclase