易变链霉菌TRM 45540四氢嘧啶合成相关基因的克隆
Cloning of Biosynthetic Gene Cluster of Ectoine from Streptomyces mutabilis TRM 45540

为了探索嗜盐放线菌对高盐环境的适应机理,以分离于罗布泊易变链霉菌TRM 45540为材料，利用分子克隆技术，构建四氢嘧啶异源生物合成工程菌(以E.coli为宿主)，对ectA、ectB、ectC与ectABC基因进行异源表达，分析异源宿主菌的耐盐能力。结果表明：TRM 45540四氢嘧啶合成相关基因ectA为 474 bp，预测编码蛋白为19 ku；ectB为1 272 bp，预测编码蛋白为44.6 ku；ectC为399 bp，预测编码蛋白为19 ku；全长基因ectABC为2 403 bp，并且携带有ectABC基因工程菌的耐盐能力显著提高。
The aim of this study is to conduct research into adaptive mechanism of halophile actinomycetes in hypersaline environments.The wide type strain Streptomyces mutabilis TRM 45540 was used as material,we inserted the ectA,ectB,ectC and ectABC into the expression vector pET28a to generate recombinant plasmids ectABC+pET-28a/BL21(DE3),then analyzed the salt tolerance of recombinants.The results showed that ectABC gene was 2 403 bp,including three subunits such as ectA,ectB and ectC.EctA gene was 474 bp,the encoding protein 19 ku,ectB gene 1 272 bp,the encoding protein 44.6 ku; ectC gene was 399 bp,the encoding protein was 19 ku.Moreover,the recombinant showed higher salt tolerance.