van den Elzen P J, Konings R N, Veltkamp E, Nijkamp H J
J Bacteriol. 1980 Nov;144(2):579-91. doi: 10.1128/jb.144.2.579-591.1980.
Escherichia coli minicells harboring plasmid CloDF13 synthesized at least 25 messenger ribonucleic acid (RNA) species; three of these RNAs, a 2,400-, a 2,200-, and a 100-nucleotide RNA, were synthesized in relatively large amounts. Using insertion and deletion mutants of CloDF13 as well as an RNA blotting technique, we could demonstrate that these three RNAs are transcripts from the CloDF13 DNA region from 0 to 40%. This region contains the cloacin and immunity genes and the genetic information involved in plasmid DNA replication. A transcription map of this region is presented and discussed. The data indicate that the cloacin and immunity genes were coordinately transcribed into messenger RNAs of about 2,400 and 2,200 nucleotides, which differ in length at their 3' terminus. RNA polymerase binding studies and in vitro transcription assays indicated that transcription of these genes initiates at a promoter located around 32% on the CloDF13 map. Furthermore, it is shown that a 100-nucleotide RNA is encoded by the CloDF13 DNA region between 7.7 and 8.8% on the plasmid genome; the synthesis of this RNA proceeds in a direction opposite to the transcription of the cloacin and immunity genes.
携带质粒CloDF13的大肠杆菌微小细胞合成了至少25种信使核糖核酸（RNA）；其中三种RNA，即2400个核苷酸、2200个核苷酸和100个核苷酸的RNA，合成量相对较大。利用CloDF13的插入和缺失突变体以及RNA印迹技术，我们能够证明这三种RNA是CloDF13 DNA区域从0到40%的转录本。该区域包含杀稻瘟菌素和免疫基因以及参与质粒DNA复制的遗传信息。本文给出并讨论了该区域的转录图谱。数据表明，杀稻瘟菌素和免疫基因被协同转录成约2400和2200个核苷酸的信使RNA，它们在3'末端的长度不同。RNA聚合酶结合研究和体外转录分析表明，这些基因的转录起始于CloDF13图谱上约32%处的一个启动子。此外，还表明一种100个核苷酸的RNA由质粒基因组上7.7%至8.8%之间的CloDF13 DNA区域编码；这种RNA的合成方向与杀稻瘟菌素和免疫基因的转录方向相反。
