摘要
枯草芽孢杆菌中有2个编码谷氨酸脱氢酶(GDH)的基因:rocG基因和gudB基因。其中Bacillus subtilis 168菌株的rocG基因编码有活性的GDH,而gudB基因编码没有活性的GDH。敲除168菌株的rocG基因后,gudB基因会自发突变为gudB1基因,后者编码有活性的GDH(gudB1-GDH)。为了研究gudB1-GDH在代谢中的作用及调控机制,构建了pMUTin4-rocG插入突变重组质粒,将其转化至B.subtilis 168,成功获得了1株rocG失活突变株BS-△rocG。对BS-△rocG和野生株的生长情况及GDH酶活进行了比较,发现BS-△rocG生长情况和野生株相当,但其GDH酶活为4.641U/mg蛋白,高于野生株的3.042U/mg蛋白。由此推测BS-△rocG中,gudB可能自发突变为gudB1,从而能够编码有活性的GDH,这一结果为研究枯草芽孢杆菌gudB1-GDH在代谢中的作用及调控机制奠定了基础。
There are two genes encoding glutamate dehydrogenases(GDH)in Bacillus subtilis,gudBand rocG.The rocGencodes an active enzyme in B.subtilis 168,however,the gudBencodes an inactive enzyme in this strain.The inactivation of the rocGgene may result in the appearance of mutations with gudBchanging into gudB1,which can encode active GDH(gudB1-GDH).In order to study the function and regulatory mechanism of gudB1-GDH,an insertionally inactivated plasmid named as pMUTin4-rocG was constructed,and it was transformed into B.subtilis 168 to generate an insertionally inactivated mutation of rocG(BS-△rocG).The BS-△rocG mutant had a similar growth rate with the wild type strain.However,the activity of its GDH(4.641U/mg protein)was higher than that of the wild type strain(3.042 U/mg protein).It suggested that the gudB1 mutation occurs during growth of BS-△rocG,which can be the basis for further study on the function and regulatory mechanism of gudB1-GDH in metabolism of B.Subtilis.
出处
《上海交通大学学报（农业科学版）》
2014年第6期32-37,共6页
Journal of Shanghai Jiaotong University(Agricultural Science)
基金
国家自然基金项目(31171737)
