Differential stringent control of the tandem E. coli ribosomal RNA promoters from the rrnA operon expressed in vivo in multicopy plasmids

• Published in: Cell Vol. 32; no. 4; pp. 1337 - 1346
• Main Authors: Sarmientos, Paolo, Sylvester, James E., Contente, Sara, Cashel, Michael
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.04.1983
• Subjects: Amino Acids - metabolism; Chloramphenicol - pharmacology; DNA, Recombinant; Escherichia coli; Escherichia coli - genetics; Escherichia coli - metabolism; Gene Expression Regulation; Guanosine Tetraphosphate - metabolism; Operon; Plasmids; RNA, Bacterial - genetics; RNA, Ribosomal - genetics; Transcription, Genetic
• ISSN: 0092-8674; 1097-4172
• DOI: 10.1016/0092-8674(83)90314-8

The tandem P 1, P 2 promoter region of the rrnA ribosomal operon has been fused to the t 1, t 2 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 predominately in the t 1 terminator region about 40 base pairs beyond the mature rrnB 5S RNA gene. Stringent control of the P 1 and P 2 promoted transcripts has been assessed in vivo. In these plasmid fusions, the upstream ( P 1) promoter activity was subject to stringent control, while the downstream ( P 2) promoter activity was inhibited by amino acid starvation in both stringent and relaxed hosts. A plasmid with an additional deletion of the P 2 region also showed stringent regulation of the P 1 promoter.