绞股蓝法呢基焦磷酸合酶基因的克隆及其序列分析

目的:克隆并分析绞股蓝法呢基焦磷酸合酶(FPS)基因的全长序列。方法:参照罗汉果法呢基焦磷酸合酶基因,设计扩增绞股蓝FPS基因的3′RACE引物,采用3'RACE和5'RACE法克隆绞股蓝FPS基因全长cDNA。结果:获得绞股蓝FPS基因全长cDNA序列共1288个核苷酸,包含一个1026核苷酸的开放读框,编码342个氨基酸残基,推断该蛋白的相对分子质量为3.94×104。NCBI Blast结果显示绞股蓝FPS基因编码蛋白的氨基酸序列与已知的植物FPS氨基酸序列的同源性为91%~74%,核酸序列的同源性为88%~78%。结论:克隆了绞股蓝FPS基因全长cDNA序列,为进一步研究绞股蓝FPS基因的表达及三萜皂苷合成通路关键酶分子的进化奠定了基础。

Cloning and Sequence Analysis of Farnesyl Pyrophosphate Synthase from Gynostemma pentaphyllum

Objective： To clone the full length cDNA encoding farnesyl pyrophosphate synthase（FPS） of Gyn ostemma pentaphyllum. Methods： According to FPS gene from Siraitia grosvertori, the primers were designed to am plify FPS gene of G.pentaphyllum in 3RACE. 3RACE and 5RACE kit were used to clone the full length eDNA of G.pentaphyllum FPS gene. Results： The full length eDNA of G.pentaphyllum FPS composed of 1288 nueleotides was obtained. The ORF of G.pentaphyllum FPS gene was 1026 bp in length, corresponding to a predicted polypep tide of 342 amino acid residues with a relative molecular mass of 3.94x10^4. The results of homologous analysis in GenBank demonstrated that the sequences had 88%-78% similarity on the nueleotide sequence and 91%-74% sim ilarity on the deduced amino acid sequence. Conclusion： The eDNA encoding FPS from G.pentaphyllum has been cloned, laying a foundation for studying the gene expression pattern of G.pentaphyllum FPS and the molecular evo lution of triterpenoid saponins key enzyme in synthesis pathway.