California Institute of Quantitative Biosciences (QB3), University of California, Berkeley, CA 94720, USA.
Phytochemistry. 2012 Jun;78:20-8. doi: 10.1016/j.phytochem.2012.02.022. Epub 2012 Mar 27.
Genome sequence analysis of Ricinus communis has indicated the presence of at least 22 putative terpene synthase (TPS) genes, 13 of which appear to encode sesquiterpene synthases (SeTPSs); however, no SeTPS genes have been isolated from this plant to date. cDNAs were recovered for six SeTPS candidates, and these were subjected to characterization in vivo and in vitro. The RcSeTPS candidates were expressed in either Escherichia coli or Saccharomyces cerevisiae strains with engineered sesquiterpene biosynthetic pathways, but only two (RcSeTPS1 and RcSeTPS7) produced detectable levels of product. In order to check whether the engineered microbial hosts were adequately engineered for sesquiterpene production, a selection of SeTPS genes was chosen from other plant species and demonstrated consistently high sesquiterpene titers. Activity could be demonstrated in vitro for two of the RcSeTPS candidates (RcSeTPS5 and RcSeTPS10) that were not observed to be functional in our microbial hosts. RcSeTPS1 produced two products, (-)-α-copaene and (+)-δ-cadinene, while RcSeTPS7 produced a single product, (E, E)-α-farnesene. Both RcSeTPS5 and RcSeTPS10 produced multiple sesquiterpenes.
蓖麻的基因组序列分析表明，至少存在 22 种假定的萜烯合酶（TPS）基因，其中 13 种似乎编码倍半萜合酶（SeTPS）；然而，迄今为止，尚未从该植物中分离出 SeTPS 基因。从 6 个 SeTPS 候选物中回收 cDNA，并在体内和体外对这些候选物进行了表征。RcSeTPS 候选物在具有工程化倍半萜生物合成途径的大肠杆菌或酿酒酵母菌株中表达，但只有两种（RcSeTPS1 和 RcSeTPS7）产生可检测水平的产物。为了检查工程微生物宿主是否充分工程化以生产倍半萜，从其他植物物种中选择了一些 SeTPS 基因，并一致显示出较高的倍半萜产量。对于两种在我们的微生物宿主中未观察到功能的 RcSeTPS 候选物（RcSeTPS5 和 RcSeTPS10），可以在体外证明其活性。RcSeTPS1 产生两种产物，(-)-α-古巴烯和(+)-δ-杜松烯，而 RcSeTPS7 仅产生一种产物，(E, E)-α-法呢烯。RcSeTPS5 和 RcSeTPS10 都产生了多种倍半萜。
