三七与其它植物FPS序列的比较分析

Comparison Analysis of FPS from Panax notoginseng with Other Plant FPS Registered in GenBank

三萜皂甙是中药三七(Panax notoginseng)的主要有效成分,为阐明三七三萜皂甙合成途径中法呢基焦磷酸合酶(FPS)的结构特征,采用RT-PCR及3-'RACE和5′-末端分析法,对三七FPS进行克隆,获得三七FPS cDNA全长,已提交GenBank,登录号为DQ059550;结合生物信息数据库及相关分析软件,对三七根FPS进行性质预测,并与GenBank中记载的植物FPS进行比对分析,构建了植物FPS系统进化树,进行聚类关系分析,根据FPS聚类关系将这些植物异戊二烯类物质合成途径的产物分组.结果表明,植物FPS有2个保守核心区,分别为DDIMD和QVQDDYLD;比对分析及构建的系统进化树表明,三七与人参、积雪草的FPS序列一致性分别为99%、95%,其三萜物质结构也相似.

Triterpenoids are the principal effective components of the traditional medicine ＇ Sanqi＇ （Panax notoginseng）. They are synthesized via the isoprene pathway. The elucidation and alteration of isoprene pathway would be beneficial for the regulation of triterpenoid biosynthesis in plants. Farnesyl pyrophosphate synthase （FPS） is one of the key enzymes for the pathway. A cDNA encoding FPS was cloned from P. notoginseng root by RT-PCR, 3r-RACE and 5r-terminal sequence analysis. Some physicochemical properties of P. notoginseng FPS were revealed by biological information resources and correlation analysis with use of EBI Clustal W and the Protein Information Resource search/analysis tool. Multiple alignment of plant FPS resulted in the construction of a phylogenetic tree of plant FPS registered in GenBank through the neighbor-joining method. The complete cDNA sequence of isolated P. notoginseng FPS was submitted to GenBank （accession no. DQ059550）. The FPS contains two conservative core fragments,DDIMD and QVQDDYLD,and shows 99% and 95% sequence identity to Panax ginseng and Centella asiatica ,respectively,with the triterpenoid structures among the above plants being very similar.