【摘要】 目的:通过构建重组质粒,异源表达4″-异戊酰基转移酶基因(4″-isovaleyltrasferase gene,ist)生产螺旋霉素。方法:在螺旋霉素的4″位加上异戊酰基侧链从而获得基因药物必特螺旋霉素基因。结果:研究表明acyB2基因是ist的正调控基因,ist基因与acyB2基因构建的ist-acyB2共表达质粒不能在变铅青链霉菌TK24中表达。启动区点突变的回复表明770bp到780bp之间有一碱基由原来的A回复成G。结论:经测序研究后发现在ist的启动区产生了一个点突变,拟回复此突变之后重新构建新的ist-acyB2载体,可用于检测ist基因在异源宿主中的表达情况。更多还原

【Abstract】 Objective:Using the recombinant plasmid,bitespiramycin was produced by expressed a heterologous 4″-isovaleryltransferase gene(ist).Method:Bitespiramycin was produced by expressing a heterologous 4″-isovaleryltransferase gene(ist)in the spiramycin producing strain to add a isovaleryl group at 4″ site of the spiramycin.Result:The acyB2 gene is positive regulator of ist gene expression.The construct of ist-acyB2 co-expression didn’t work in the S.lividans TK24.One single mutation was identified in the promoter region of ist gene.Conclusion:We plan to recover this mutation and construct a new plasmid containing the ist-acyB2 genes,then transform this plasmid to cell and check the situation of ist expression.更多还原