基因xylE编码的邻苯二酚2，3－双加氧酶在大肠杆菌中的亚克隆与高表达

Subcloning and high level expression of xylE gene coding for the catechol 2,3 dioxygenase in E.coli

目的：构建ｘｙｌＥ基因高表达菌株，为快速检测芳香类化合物污染提供可能。方法和结果：通过ＰＣＲ扩增，将位于质粒ｐＴＧ４０２上的ｘｙｌＥ基因进行扩增，克隆于ｐＵＣ１１８Ｎ和ｐＵＣ１１９Ｎ上，经双向测序，证明ＰＣＲ过程中并未发生突变，然后进一步克隆于高表达载体ｐＪＬＡ５０３，转化Ｅ．ｃｏｌｉＴＧ１，经４２℃诱导，获得了高表达的基因产物，表达量占全菌总蛋白的３４．２％。结论：ｘｙｌＥ基因在大肠杆菌中获得了高表达。

Objective:High level expression of xylE gene in E.coli is available to detect aromatic compound environment pollution.Methods and Results:The xylE gene which codes for the catechol 2,3 dioxygenase(CatO2ase) was amplified from the recombinant plasmid pTG402 by using PCR technique and was subcloned onto pUC118N and pUC119N.The single stranded recombinant phage DNA from the transformed E.coli MV1184 cells was used for sequencing.The sequence of xylE gene was proved to be the same as reported.The gene was then subcloned onto the high expression plasmid pJLA503,and its expression amount was about 34.2% in total bacterial proteins.Conclusion:xylE gene is highly expressed in host E.coli TG1.