Taschke C, Klinkert M Q, Pirkl E, Herrmann R
Department of Microbiology, University of Heidelberg, FRG.
Isr J Med Sci. 1987 May;23(5):347-51.
In Mycoplasma hyopneumoniae, the single genes for 16S and 23S rRNAs are clustered in one operon from which the 5S rRNA gene is separated by more than 4 kbp. This operon, gene 2413 and gene X from M. hyopneumoniae and the 5' ends of both rRNA operons from M. capricolum were cloned and used for analysis of the following gene expression signals: promoters and terminators of the DNA-directed RNA polymerase, ribosomal binding sites of mRNA, and sites for processing of precursor rRNA. The analyses were performed by nuclease S1 protection experiments, the primer extension technique, and DNA sequencing. From these studies we conclude that putative promoter sequences in M. hyopneumoniae deviate significantly from those in Escherichia coli and Bacillus subtilis in having its -35 consensus sequence replaced by A-T rich sequences, whereas the characterized M. capricolum promoter resembles more closely a typical E. coli promoter. The other expression signals show sequences or structures similar to those found in other eubacteria, indicating related underlying principles.
在猪肺炎支原体中，16S和23S rRNA的单个基因聚集在一个操纵子中，5S rRNA基因与之相隔超过4千碱基对。克隆了该操纵子、猪肺炎支原体的基因2413和基因X以及山羊支原体两个rRNA操纵子的5'端，并用于分析以下基因表达信号：DNA指导的RNA聚合酶的启动子和终止子、mRNA的核糖体结合位点以及前体rRNA的加工位点。通过核酸酶S1保护实验、引物延伸技术和DNA测序进行分析。从这些研究中我们得出结论，猪肺炎支原体中假定的启动子序列与大肠杆菌和枯草芽孢杆菌中的启动子序列有显著差异，其-35共有序列被富含A-T的序列取代，而已鉴定的山羊支原体启动子更类似于典型的大肠杆菌启动子。其他表达信号显示出与其他真细菌中发现的序列或结构相似，表明存在相关的潜在原理。
