大戟甲羟戊酸途径关键酶基因hmgr的克隆与分析

Cloning and Analysis of a cDNA Encoding Key Enzyme Gene (hmgr) of the MVA Pathway in Medicinal Plant Euphorbia pekinensis

通过比较6种植物8条甲羟戊酸途径关键酶3-羟基-3-甲基戊二酰辅酶A还原酶(HMGR)基因同源区域,设计简并引物,利用RT-PCR技术成功地从大戟(Euphorbia pekinensis)叶中扩增出458bp的基因片段。通过BlastP比较,所推断的大戟HMGR蛋白序列与杜仲Eucommia ulmoides(AAV54051)、穿心莲Andrographis paniculata(AAP14352)、胡黄连Picrorhiza kurrooa(ABC74565)、橡胶树Hevea brasiliensis(AAU08214)、海岛棉Gossypium barba-dense(ABC71314)、龙胆草Gentiana lutea(BAE92730)的一致性分别达到90%、86%、86%、92%、87%和88%。蛋白质保守区、特征区以及进化树分析,初步证实该基因为hmgr基因,这是首次报道从药用植物大戟中克隆到甲羟戊酸途径关键酶HMGR的基因片段。

Based on the design of degenerated oligonucleotides according to the conservative regions of eight 3-hydroxy-3-methylglutaryl-CoA reductases from six plants and total RNA extracted from Euphorbia pekinensis,a 458 bp fragment of hmgr was obtained using reverse transcription PCR strategy. Through sequence analysis by BlastP online, the resulting protein showed high homology to 3-hydroxy-3-methylglutaryl-CoA reductase, with 90% identification compared with Eucommia ulmoides （ AAV54051 ）, 86% with Andrographis paniculata （AAP14352） ,86% with Picrorhiza kurrooa （ABC74565） ,92% with Hevea brasiliensis （AAU08214）, 87% with Gossypium barbadense （ABC71314） and 88% with Gentiana lutea （BAE92730）. Deduced amino acid sequence were also analyzed by PROSITE, ClustalX and Phylogenic tree, and data present evidence for the existence of 3-hydroxy-3-methylglutaryl-CoA reductase in E. pekinensis,which is the first report of the hmgr gene isolated from E. pekinensis.