Gafny R, Hyman H C, Razin S, Glaser G
Department of Cellular Biochemistry, Hebrew University-Hadassah Medical School, Jerusalem, Israel.
Nucleic Acids Res. 1988 Jan 11;16(1):61-76. doi: 10.1093/nar/16.1.61.
The 5' region of the rRNA operon, rrnA, of M. capricolum was cloned. Sequence analysis revealed two tRNA genes, tRNA(leu) and tRNA(lys), upstream to the promoter of the rRNA operon. The in vivo transcription start sites of the rRNA operon and of the tRNA genes were mapped. The same promoters used by M. capricolum RNA polymerase are also recognized by E. coli RNA polymerase both in vivo and in vitro. We find that high levels of ppGpp in E. coli, resulting from amino acid starvation or from spoT mutation, activate rather than repress the transcription of the mycoplasma rrnA operon.
山羊支原体rRNA操纵子rrnA的5'区域被克隆。序列分析显示在rRNA操纵子启动子上游有两个tRNA基因，即tRNA(leu)和tRNA(lys)。绘制了rRNA操纵子和tRNA基因的体内转录起始位点。山羊支原体RNA聚合酶使用的相同启动子在体内和体外也能被大肠杆菌RNA聚合酶识别。我们发现，大肠杆菌中因氨基酸饥饿或spoT突变导致的高水平ppGpp会激活而非抑制支原体rrnA操纵子的转录。
