Ⅰ型聚酮类天然产物中利用点突变产生类似物的研究

点突变是指通过聚合酶链式反应（PCR）等方法向目的DNA片段中引入所需变化（通常是表征有利方向的变化）,包括碱基的添加、删除、改变等。通过构建发生突变的质粒利用遗传转移的方法同源重组到野生型基因组中,使得氨基酸改变从而引起蛋白功能发生变化,获得鉴定正确的突变株后发酵筛选结构类似物。聚酮类天然产物在生物合成过程中,其聚酮链会发生若干步氧化还原反应,通过点突变的方法失活该蛋白,从而跳过该步氧化还原反应的作用,产生PKS骨架上的改变,从而得到结构类似物。

Study of Analogues in Polyketides Compounds Type I Produced by Site Mutation

Site mutation is a method to change the DNA strand about the purpose strains by PCR(the change always towards the positive side),including add,delete or change the bases.Changing the amino acid by homologous recombination via conjugation transfer between the wild type strain and the mutation plasmid,the function of protein is altered,even abolished.Then screening the right mutant and fermenting to find the new expected structural analogues.During the biosynthesis of polyketide natural products,there are many oxidation-reduction reactions,so skip some step which the inactivation protein can not catalytic,get the change in the PKS skeleton and then the new analogues.