Kajikawa Masataka, Yamato Katsuyuki T, Fukuzawa Hideya, Sakai Yasuyoshi, Uchida Hidenobu, Ohyama Kanji
Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan.
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.
麻风树，即所谓的石油植物，能产生大量的三萜类化合物，如β-香树脂醇。基于已知β-香树脂醇合酶之间保守序列的简并RT-PCR技术，从麻风树叶片中克隆出一个假定的三萜合酶cDNA，即EtAS。EtAS cDNA推导的氨基酸序列与人参β-香树脂醇合酶的同源性最高，为82%。将EtAS开放阅读框在甲基营养型酵母毕赤酵母中进行异源表达，结果产生了β-香树脂醇，这表明EtAS cDNA编码一种β-香树脂醇合酶。这是关于大戟科植物三萜合成途径相关基因的首次报道。
