Wek R C, Hatfield G W
Nucleic Acids Res. 1986 Mar 25;14(6):2763-77. doi: 10.1093/nar/14.6.2763.
The ilvGMEDA operon of Escherichia coli K-12 contains an internal promoter, PE, in the distal portion of the ilvM gene immediately upstream from the ilvE gene. The location of this promoter was determined using S1 nuclease protection analyses of in vivo and in vitro transcripts. The transcriptional activity of the internal promoter was compared to the transcriptional activity of the operon-proximal promoter P1P2 using transcriptional fusion vectors and plasmid copy number determinations. These measurements showed that the P1P2 promoter is 52-fold stronger than the internal PE promoter. Estimates of the transcriptional role of the internal promoter on ilvE gene expression during growth conditions in excess and limiting branch chain amino acids is presented.
大肠杆菌K-12的ilvGMEDA操纵子在ilvM基因紧邻ilvE基因上游的远端部分含有一个内部启动子PE。该启动子的位置通过对体内和体外转录本进行S1核酸酶保护分析来确定。使用转录融合载体和质粒拷贝数测定法，将内部启动子的转录活性与操纵子近端启动子P1P2的转录活性进行了比较。这些测量结果表明，P1P2启动子比内部PE启动子强52倍。本文给出了在过量和限制支链氨基酸生长条件下内部启动子对ilvE基因表达的转录作用估计。
