[关键词]
[摘要]
目的 克隆获得黄花蒿MEP途径中必需关键酶——羟甲基丁烯基-4-磷酸合成酶基因(HDS),并进行生物信息学分析和功能互补分析研究。方法 对已知的其他种子植物HDS基因的核苷酸序列进行多重序列比对,选取保守区域设计简并引物,利用同源扩增和cDNA末端快速扩增技术从黄花蒿中获得目的基因;利用BLAST进行序列比对,ORF Finder寻找开放阅读框,并用MEGA3.0中的临位相联法构建进化树。结果 得到1条长2 324 bp的HDS cDNA序列,其ORF框长1 854 bp,编码617个氨基酸残基的蛋白;生物信息学分析显示,黄花蒿HDS基因AaHDS与其他种子植物来源的HDS高度同源;功能互补分析表明,AaHDS能互补突变菌株Escherichia coli MG1655 ara<>HDS中缺失的HDS功能,使突变菌株恢复生长,证明AaHDS具有典型的HDS基因功能。结论 首次克隆获得黄花蒿HDS基因,为青蒿素的代谢工程研究提供相应的基础。
[Key word]
[Abstract]
Objective To obtain the indispensable key enzyme—hydroxide methyl enylamino 4-cyclodiphosphate synthase (HDS) gene involved in the MEP pathway cloned from Artemisia annua and conduct bioinformatic and functional complementation analysis. Methods To perform multiple sequence alignment for the nucleotide acid sequence of the other reported seed plants’ HDS gene, to select conservative areas for designing degenerate primers, and to gain the aim gene from A. annua through homologous expanding and cDNA bottom speedily expanding technique. To perform sequence alignment using BLAST, to identify open reading frame (ORF) using ORF Finder, and to construct phylogenetic tree using neighbor joining (NJ) ways in MEGA3.0. Results The obtained HDS cDNA sequence was 2 324 bp containing a 1 854 bp ORF and encoding a 617-aminoacid protein. Bioinformatic analysis showed that AaHDS was homologous with HDS derived from other seed plant species. Functional complementation analysis indicated that AaHDS could make up the short HDS function of mutant Escherichia coli MG1655 ara<>HDS. It could make the mutant get back to upgrowth, which showed AaHDS had typical HDS gene function. Conclusion The cloning HDS gene from A. annua for the first time provides a good basis for further study on the metabolization project of artemisinin.
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[基金项目]
重庆市教委自然科学研究资助项目(kj071204)