黄单胞菌(Xanthomonas campestris)XA5-5β-葡萄糖苷酶基因的克隆与表达  

CLONING AND EXPRESSION OF β-GLUCOSIDASE GENE IN XANTHOMONAS CAMPESTRIS XA5-5

作　　者：邹文[1] 刘纯强[1] 高东 王祖农[1] 

机构地区：[1]山东大学微生物研究所,济南250100

出　　处：《微生物学报》1994年第4期271-278,共8页Acta Microbiologica Sinica

基　　金："七五"攻关项目;国家青年科学基金项目

摘　　要：以黄单胞菌(Xanthomonas campestris)XA5-5为供体菌,广泛寄主质粒pRK404为载体,在大肠杆菌中克隆了一个β-葡萄糖苷酶基因,重组质粒pLZS1外源片段为1.1kb,将pLZS1接合导入黄单胞菌XA5-5,得到了克隆子XA5-5(pLZS1).以水杨苷为底物,XA5-5(pLZS1)的酶活性大大高于E.Coli JM83(pLZS1).并且质粒在XA5-5中能相对稳定地存在.初步结果表明,所克隆的基因编码的产物对于水杨苷底物有较强的亲和力,并可以在一定程度上降低XA5-5中酶与pNPG底物的亲和力,使其酶活减小.A*-glucosidase gene from Xanthomonas campestris XA5-5 was cloned in Escherichia coli with the broad-host-range plasmid pRK404. The *-glucosidase encoding plasmid designated pLZS1 contained a 1.1kb PstI DNA fragment deriving from XA5-5. The plasmid pLZS1 was transconjugated by filter mating into XA5-5 producing homologous clones XA5-5(pLZS1). Plasmid stability analysis revealed that pLZSl was more stable in XA5-5 than in E. colt JM83. The level of β-glucosidase expressed in XA5-5(pLZSl) was much higher than in E. coli JM83(pLZS1) using salicin as the substrate. From the results obtained, it seems that the gene product of this cloned DNA fragment has higher affinity to salicin substrate, and in some sense reduces the affinity between the enzyme and pNPG substrate in XA5-5.

关 键 词：黄单胞菌 β 葡萄糖甙酶 基因 

分 类 号：Q939.110.3[生物学—微生物学]