Tanaka K, Ueguchi C, Mizuno T
Laboratory of Molecular Microbiology, School of Agriculture, Nagoya University, Japan.
Biosci Biotechnol Biochem. 1994 Jun;58(6):1097-1101. doi: 10.1271/bbb.58.1097.
The mechanism by which the Escherichia coli proV promoter is activated more than 100-fold in response to the medium osmolarity, without the help of any known trans-acting activators, is not yet fully understood. In this context, it has recently begun to be realized that structural features, not the primary sequences, of cis-acting DNA elements may be important for transcriptional regulation in prokaryotes. From this point of view, in this study the proV promoter was characterized by constructing a series of spacer-insertion mutants in a proV-lacZ fusion on the chromosome. Here it was found that the upstream cis-acting sequence must be positioned stereospecifically with respect to the principal -35 and -10 regions for the proV promoter to be fully activated. In this regard, it was suggested that an overall DNA structure, particularly DNA curvature, is an important cis-acting parameter for activation of the proV promoter.
在没有任何已知反式作用激活因子的情况下，大肠杆菌proV启动子如何响应培养基渗透压而被激活100多倍，其机制尚未完全明确。在这种背景下，人们最近开始意识到，顺式作用DNA元件的结构特征而非一级序列，对于原核生物的转录调控可能很重要。从这一观点出发，本研究通过在染色体上构建一系列proV-lacZ融合体的间隔插入突变体，对proV启动子进行了表征。结果发现，上游顺式作用序列必须相对于主要的-35和-10区域进行立体特异性定位，proV启动子才能被完全激活。在这方面，有人提出整体DNA结构，特别是DNA曲率，是激活proV启动子的一个重要顺式作用参数。
