AUTO-REGULATION OF THE DNA-REPLICATION GENE DNAA IN ESCHERICHIA-COLI K-12
AUTO-REGULATION OF THE DNA-REPLICATION GENE DNAA IN ESCHERICHIA-COLI K-12
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DOI：
10.1016/0092-8674(85)90319-8
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发表时间：
1985-01-01
期刊：
影响因子：
64.5
通讯作者：
WRIGHT, A
中科院分区：
文献类型：
--
作者：
BRAUN, RE;ODAY, K;WRIGHT, A
在E. coli K-12是DNA复制起始所必需的。虽然dnaA蛋白的具体功能尚不清楚，但有人认为它是启动频率的调节剂。体内dnaA-lacZ翻译融合体和dnaA-trpA-lacZ转录融合体的表达对功能性dnaA蛋白水平的变化敏感。dnaA基因产物的过量产生导致两种融合体的表达减少，而dnaA-等位基因的引入导致表达增加。dnaA启动子/调控区的缺失分析结果表明，这两个dnaA启动子调控的dnaA基因产物和2个启动子之间的网站是负责的调节。DNA酶保护实验表明，dnaA蛋白在2个dnaA启动子区域与DNA结合。结果表明，dnaA基因产物通过抑制其两个启动子的转录来调节其自身的合成。
The dnaA gene in E. coli K-12 is required for the initiation of DNA replication. Although the specific function of the dnaA protein is unknown, it has been suggested that it is a regulator of the frequency of initiation. The expression of both a dnaA-lacZ translational fusion and a dnaA-trpA-lacZ transcriptional fusion in vivo are sensitive to changes in the level of functional dnaA protein. Overproduction of the dnaA gene product leads to a reduction in expression from both fusions while introduction of dnaA- alleles results in an increased expression. Results from a deletion analysis of the dnaA promotor/regulatory region suggest that both dnaA promotors are regulated by the dnaA gene product and that a site between the 2 promotors is responsible for the regulation. DNase protection experiments showed that the dnaA protein binds to DNA in the region of the 2 dnaA promotors. The results indicate that the dnaA gene product regulates its own synthesis by inhibiting transcription from both of its promotors.