Thayer G C, Brosius J
Mol Gen Genet. 1985;199(1):55-8. doi: 10.1007/BF00327509.
In order to characterize the tandem rrnB promoters transcribing one of the ribosomal RNA operons in E. coli we subcloned the basic promoter unit. This 185 bp fragment extends from -64 to +121 counted from the transcription start site of upstream promoter P1. The start site of downstream promoter P2 is also included in the promoter cartridge. S1 mapping experiments show that both promoters on this fragment are active in vivo. BAL-31 deletion mutations generated at the start site for promoter P2 were also tested by S1 mapping. Transcription from P2 remained active in all cases with the exception of one construction which lacks the -10 region. This demonstrates that the sequences downstream from the -10 region of P2 are not essential for basic promoter function.
为了表征转录大肠杆菌中一个核糖体RNA操纵子的串联rrnB启动子，我们亚克隆了基本启动子单元。这个185 bp的片段从上游启动子P1的转录起始位点开始计数，延伸至-64到+121。启动子盒中还包含下游启动子P2的起始位点。S1图谱实验表明，该片段上的两个启动子在体内均具有活性。还通过S1图谱对在启动子P2起始位点产生的BAL-31缺失突变进行了测试。除了一个缺少-10区域的构建体之外，在所有情况下，来自P2的转录均保持活性。这表明P2的-10区域下游的序列对于基本启动子功能不是必需的。
