DndB蛋白负调控变铅青链霉菌dndA基因转录  

DndB Protein Negatively Regulates dndA Gene Transcription in Streptomyces lividans

作　　者：戴道凤 徐冬梅 汪志军[3] 唐爱发 Dai Daofeng;Xu Dongmei;Wang Zhijun;Tang Aifa(Zhongshan School of Medicine,Sun Yat-Sen University,Guanghou,510080;Guangdong Key Laboratory of Systems Biology and Synthetic Biolo-gy for Urogenital Tumors,Shenzhen Second People's Hospital,First Afiliated Hospital of Shenzhen University,Shenzhen,518035;State Key Labo-ratory of Microbial Mctabolism and School ofLife Science and Biotechnology,College of Life Science and Technology,Shanghai JiaoTong University,Shanghai,200240;Department of Food and Drug Engineering,Shijiazhuang University of Applied Technology,Shijiazhuang,050081)

机构地区：[1]中山大学中山医学院,广州510080 [2]深圳大学第一附属医院,深圳市第二人民医院,广东省泌尿生殖肿瘤系统和合成生物学研究重点实验室,深圳518035 [3]上海交通大学,生命科学技术学院,微生物代谢国家重点实验室,上海200240 [4]石家庄职业技术学院,食品与药品工程系,石家庄050081

出　　处：《基因组学与应用生物学》2020年第6期2599-2606,共8页Genomics and Applied Biology

基　　金：深圳市高水平大学医科建设(No.2016031638);深圳科学与技术计划(No.JSGG20160301162913683);深圳医学三名工程(No.SZSM201612031);中国博士后科学基金(No.2018M633215);国家自然科学基金(No.31470830,No.21661140002,No.91753123)共同资助。

摘　　要：为了探究变铅青链霉菌dndA基因转录调控机制,本研究利用LC-MS分析了野生型变铅青链霉菌1326和dndB基因同框缺失菌株HXY2的DNA硫修饰丰度差异。通过半定量RT-PCR比较dndA基因在1326与HXY2中的表达差异。用儿茶酚2,3-双加氧酶活力检测实验和对dndA启动子区域进行删除或突变来确定负责dndA基因表达调控的顺式作用元件。研究发现,HXY2的DNA硫修饰丰度高于1326,dndA基因在HXY2中的表达高于1326。儿茶酚2,3-双加氧酶活力检测实验显示,删除或突变r重复序列能使1326的dndA启动子活力明显升高。突变r重复序列后,HXY2的dndA启动子活力没有明显变化。结果显示,DndB蛋白抑制dndA基因转录进而下调DNA硫修饰丰度,以及DndB蛋白通过结合到r重复序列而抑制dndA基因转录。这是首次对dndA基因的转录调控机制进行研究,并且本研究进一步丰富了DndB蛋白的调控机理。The objective of this study is to explore the mechanism of regulation of dndA gene transcription in Streptomyces lividans.We used LC-MS to analyze the differences in DNA sulfur modification intensity between wild type Streptomyces lividans 1326 and dndB gene in-frame deletion strain HXY2.We compared the differences in dndA gene expression between 1326 and HXY2 with semi-quantitative RT-PCR.Utilizing catechol 2,3-dioxygenase assays and deletion or mutation of dndA promoter region,we determined the cis-acting element responsible for the regulation of dndA gene expression.We found that DNA sulfur modification intensity in HXY2 was higher than that in 1326,and dndA gene expression in HXY2 was elevated,compared to that in 1326.The catechol 2,3-dioxygenase assays showed that deletion or mutation of r repeat sequence resulted in a significant increase in dndA promoter activity in 1326.Mutation of r repeat sequence had no effect on dndA promoter activity in HXY2.These results suggested that DndB protein inhibits dndA gene transcription to downregulate DNA sulfur modification intensity,and that DndB protein binds r repeat sequence to inhibit dndA gene transcription.This is the first time to study the mechanism of regulation of dndA gene transcription,and this research further enriches the regulation mechanism of DndB protein.

关 键 词：变铅青链霉菌 DndB蛋白 dndA基因 调控 

分 类 号：Q933[生物学—微生物学]