甘草鲨烯合酶基因及cDNA的克隆与序列分析

目的:对甘草鲨烯合酶(SQS)基因的cDNA及DNA进行克隆及序列分析.方法:根据已报道的光果甘草SQS1基因的cDNA序列设计引物,采用RT-PCR的方法,提取甘草根的RNA然后反转录成cDNA,以cDNA为模板,扩增出SQS基因的cDNA序列,以甘草总DNA为模板,扩增SQS的DNA序列.结果:序列分析表明,克隆获得的甘草SQS1的cDNA编码区为1242 bp,编码413个氨基酸残基,命名为GuSQS1,登录号为GQ266154,与卢虹玉等报道的甘草的2个SQS(SQS1和SQS2)的氨基酸序列一致性为98.55%,88.62%,对应DNA序列全长为4484 bp,含有13个外显子,12个内含子,登录号为GQ180932.结论:甘草SQS的cDNA及DNA序列的获得为进一步研究甘草酸生物合成机制提供了基础.

Cloning and sequence analysis of squalene synthase gene and cDNA in Glycyrrhiza uralensis

Objective : To clone and sequence the open reading frame and genomic sequence of squalene synthase (SQS) from Glycyrrhiza uralensis. Method : The primers were designed according to cDNA sequence of SQS from G. glabra reported by Hiroaki HAYASHI, SQS cDNA was cloned with total RNA extracted from roots of G. uralensis. Specific fragments were amplified by RT-PCR and then were cloned and sequenced. SQS DNA was cloned with total DNA extracted from roots of G. uralensis. Specific fragments were amplified by PCR and then were cloned and sequenced. Result : GuSQS1 (GenBank accession number: GQ266154) was 1 242 bp in length encoding proteins with 412 amino acid. NCBI Blast x search results showed GuSQS1 had the highest amino acid similarity to the corresponding proteins from G. uralensis The identities of GuSQS1 with the two proteins were 98. 55% and 88. 62%. SQS (GenBank accession number: GQ180932) gene with 4 484 bp containing 13 exons and 12 introns was then amplified by PCR with genomic DNA extracted from roots of G. uralensis. Conclusion : These findings of cloning and sequencing the open reading frame and genomic sequence of squalene synthase (SQS) from G. uralensis brought some new clues for the further exploration of SmSQS function in sterol and terpenes biosynthesis.