Sarmientos P, Sylvester J E, Contente S, Cashel M
Cell. 1983 Apr;32(4):1337-46. doi: 10.1016/0092-8674(83)90314-8.
The tandem P1, P2 promoter region of the rrnA ribosomal operon has been fused to the t1, t2 terminator region of the rrnB operon in pBR322 plasmid derivatives. This deletes most internal RNA structural elements ordinarily processed out of ribosomal operon transcripts. In vivo as well as in vitro transcripts arising from both promoters terminate predominantly in the t1 terminator region about 40 base pairs beyond the mature rrnB 5S RNA gene. Stringent control of the P1 and P2 promoted transcripts has been assessed in vivo. In these plasmid fusions, the upstream (P1) promoter activity was subject to stringent control, while the downstream (P2) promoter activity was inhibited by amino acid starvation in both stringent and relaxed hosts. A plasmid with an additional deletion of the P2 region also showed stringent regulation of the P1 promoter.
rrnA核糖体操纵子的串联P1、P2启动子区域已与pBR322质粒衍生物中rrnB操纵子的t1、t2终止子区域融合。这删除了通常在核糖体操纵子转录本中加工去除的大多数内部RNA结构元件。来自两个启动子的体内和体外转录本主要在成熟rrnB 5S RNA基因下游约40个碱基对处的t1终止子区域终止。已在体内评估了对P1和P2启动转录本的严格控制。在这些质粒融合物中，上游（P1）启动子活性受到严格控制，而下游（P2）启动子活性在严格和松弛宿主中均受到氨基酸饥饿的抑制。一个额外缺失P2区域的质粒也显示了对P1启动子的严格调控。
