Shen P, Zengel J M, Lindahl L
Department of Biology, University of Rochester, NY 14627.
Nucleic Acids Res. 1988 Sep 26;16(18):8905-24. doi: 10.1093/nar/16.18.8905.
Genetic analysis of the autogenous control of the S10 ribosomal protein operon of Escherichia coli has suggested that the secondary or tertiary structure of the leader transcript is important for this regulation. We have therefore determined the secondary structure of the leader by enzyme digestion and chemical modification. Our results suggest that the 172 base leader exists in two forms, differing only immediately upstream of the Shine-Dalgarno sequence of the first gene. We discuss the possibility that the equilibrium between these alternate structures is important for the L4-mediated regulation of translation of the S10 operon. We have also determined the structure of several mutant transcripts. Correlation of these structures with the regulatory phenotypes suggest that a hairpin about 50 bases upstream of the first gene is essential for the control of translation of the operon. Finally, our results show that a two base substitution in an eight base loop destabilizes the attached stem.
对大肠杆菌S10核糖体蛋白操纵子自身调控的遗传分析表明，前导转录本的二级或三级结构对这种调控很重要。因此，我们通过酶切和化学修饰确定了前导序列的二级结构。我们的结果表明，172个碱基的前导序列以两种形式存在，仅在第一个基因的Shine-Dalgarno序列上游紧邻区域有所不同。我们讨论了这些交替结构之间的平衡对L4介导的S10操纵子翻译调控很重要的可能性。我们还确定了几种突变转录本的结构。这些结构与调控表型的相关性表明，第一个基因上游约50个碱基处的一个发夹结构对于操纵子翻译的控制至关重要。最后，我们的结果表明，一个八碱基环中的两个碱基替换会使相连的茎不稳定。
