大肠杆菌葡萄糖异构酶基因在变铅青链霉菌中的克隆与表达

Cloning and Expression of E. colt Glucose Isomerase Gene in Streptomyces lividans

本文用穿梭质粒载体pSE-3,进行了大肠杆菌葡萄糖异构酶基因在变铅青链霉菌中的克隆与表达。把含有1.6kb葡萄糖异构酶基因的pX1200(4.3kb)质粒与pGEM-3(2.9kb)质粒分别用EcoRI酶解,T4DNA连接酶连接,转化E.Coli HB101(Xy1^-,Neo(?)),得到的重组质粒被命名为pX1203(7.2kb);将pX1203与穿梭质粒载体pSE-3分别用HindⅢ酶解,T_4DNA连接酶连接,转化E.Coli HB101,在含有新霉素的木糖培养基上筛选到转化重组体,其重组质粒被命名为pSE×100(10.6kb);把pSE×100转化变铅青链霉菌TK54的原生质体,在硫链丝菌肽(50μg/ml)和新霉素(50μg/ml)的平皿上得到了重组体。经质粒提取,酶切分析,再转化和葡萄糖异构酶活性测定,结果表明,大肠杆菌的葡萄糖异构酶基因确实已在链霉菌中克隆和表达。

E. colt glucose isomerase gene was cloned into Streptomyces lividans using shuttle plasmid vector pSE-3. First plasmid pXI203 was constructed in E. coli using plasmids pXI200 (containing 1.6 kb glucose isomerase gene) and pGEM-3 digested with EcoR1. Then, recombinant plasmid pSEX100 was also constructed in E. coli using plasmids pXI203 and pSE-3 digested with Hindμ. When the pSEX100 was transformed into Streptomyces lividans protoplasts, recom-binants were obtained on R5YE medium containing 50 μg/ml neomycinn and 50 μg/ml chiostrc-pton.The results showed that the E. coli glucose isomerase gene cloned and expressed in Streptomyces lividans via the analysis of restriction enzyme digestion as well as the detection of the glucose isomerase activity