Molecular cloning and analysis of requlatory-strucutral genes for arginine biosynthtic pathway in Bacillus amyloliquefaciens

作为与大肠杆菌比较的模式系统，我们将对淀粉液化芽孢杆菌的arg基因结构及其分子遗传特性进行研究。在大肠杆菌的例子中，除了从谷氨酸生物合成精氨酸的argECBH簇之外，其他基因在染色体上没有紧密连锁。它们的表达也受到非连锁基因argR产物的调节。许多研究人员已经对大肠杆菌中arg基因和操纵子的结构进行了研究。虽然在其他微生物中对Arg营养缺陷体和精氨酸的生物合成的研究很少，但芽孢杆菌Arg基因的分子遗传学仍有待阐明。在Min教授的实验室中，已经克隆并研究了谷氨酸棒杆菌的argEC基因和Arg操纵子。因此，我们将通过对E.coliArg营养缺陷型突变株的互补分析，克隆淀粉液化芽孢杆菌中的arg基因。在核苷酸序列分析后，将与大肠杆菌和棒状杆菌系统的基因组织和调控进行比较。

As a model system to compare with those of Escherichia coli, the structure of the arg genes and their molecular genetic property in Bacillus amyloliquefaciens will be investigated. In the case of E.coli, other genes except for the argECBH cluster for the biosynthesis of arginine from glutamate are not tightly linked on the chromosome. Their expressions are also requlated by the product of unlinked gene, argR.The structure of the arg genes and the operon in E.coli has been studied by many researchers. Although the study on the arg auxotroph and the biosynthesis of arginine have been done a little in other microorganisms, molecular genetics of arg genes in Bacillus sp.remains to be elucidated. In professor Min's laboratory the argEC genes and the arg operon in Corynebacterium glutamicum has been cloned and studied. Therefore, the arg genes in Bacillus amyloliquefaciens will be cloned by a complementation analysis of E.coli arg auxotropic mutant. After the nucleotide sequence analysis, the gene organization and requlation of the arg operon in the B.amyloliquefaciens chromosome will be compared with those of E.coli and Corynebacterium system.