DNA DETERMINANTS OF RIBOSOMAL-RNA SYNTHESIS IN ESCHERICHIA-COLI - GROWTH-RATE DEPENDENT REGULATION, FEEDBACK INHIBITION, UPSTREAM ACTIVATION, ANTITERMINATION
DNA DETERMINANTS OF RIBOSOMAL-RNA SYNTHESIS IN ESCHERICHIA-COLI - GROWTH-RATE DEPENDENT REGULATION, FEEDBACK INHIBITION, UPSTREAM ACTIVATION, ANTITERMINATION
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DOI：
10.1016/0092-8674(86)90498-8
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发表时间：
1986-01-01
期刊：
影响因子：
64.5
通讯作者：
NOMURA, M
中科院分区：
文献类型：
--
作者：
GOURSE, RL;DEBOER, HA;NOMURA, M
我们研究了E.使用启动子-lacZ和λ PL-rrnB操纵子融合体在大肠杆菌中表达。相对于P1启动子转录起始位点的-51和-20之间的序列包含生长速率依赖性控制的关键信息。生长速率调节所必需的区域与反馈抑制所必需的区域相同。在-51和-88之间的一个单独的上游区域使rRNA转录增加至少15倍，并且似乎具有异常构象。启动子P2下游的盒A序列，而不是P2和盒A之间的DNA，是有效的rRNA链延伸所必需的。这些结果表明，无论是上游激活，也不antitermination决定生长速率的依赖性。相反，生长速率调节发生在负反馈系统的靶位点，即P1启动子本身。我们认为负反馈调节是导致大肠杆菌rRNA合成的生长速率依赖性的原因。杆菌
We have examined the DNA regions required for rRNA synthesis in E. coli using promoter-lacZ and .lambda.PL-rrnB operon fusions. Sequences between -51 and -20 with respect to the P1 promoter transcription initiation site contain the critical information for growth rate dependent control. The region essential for growth rate regulation is the same as that necessary for feedback inhibition. A separate upstream region, between -51 and -88, increases rRNA transcription at least 15-fold and appears to have an abnormal conformation. The box A sequence downstream of promoter P2, but not DNA between P2 and box A, is required for efficient rRNA chain elongation. These results indicate that neither upstream activation nor antitermination determines growth rate dependence. Rather, growth rate regulation takes place at the target site for the negative feedback system, the P1 promoter itself. We propose that negative feedback regulation is responsible for the growth rate dependence of rRNA synthesis in E. coli.