Activity of a plasmid-borne leu-500 promoter depends on the transcription and translation of an adjacent gene

Chen, Dongrong, Bowater, Richard, Dorman, Charles J. and Lilley, David M.J. (1992) Activity of a plasmid-borne leu-500 promoter depends on the transcription and translation of an adjacent gene. Proceedings of the National Academy of Sciences of the United States of America, 89 (18). pp. 8784-8788. ISSN 0027-8424

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Abstract

leu-500 is a chromosomal promoter mutation in Salmonella typhimurium that normally causes the promoter to be inactive in the initiation of RNA synthesis. But in a strain that has mutations in topA, the gene encoding DNA topoisomerase I, the mutant promoter becomes active. We show that the leu-500 promoter can function on a plasmid when it is adjacent to the tetracycline-resistance gene tetA. Activation of the leu-500 promoter requires that the tetA gene is transcribed and translated and that the host cell is top A. We propose that the A → G mutation in the -10 region of the leu-500 promoter is compensated by local negative supercoiling arising from transcription of the tetA gene, which may reach elevated levels in a topA background, provided that diffusional dissipation is reduced due to anchoring of the TetA peptide in the membrane. This is a clear example of the modulation of the activity of a promoter by the activity of another promoter in cis, when they can be coupled through the topology of the template. (.

Item Type:	Article
Uncontrolled Keywords:	dna supercoiling,leu-500 mutation,topoisomerase,topological coupling,twin supercoiled domains,general ,/dk/atira/pure/subjectarea/asjc/1000
Faculty \ School:	Faculty of Science > School of Biological Sciences
UEA Research Groups:	Faculty of Science > Research Groups > Biosciences Teaching and Education Research Faculty of Science > Research Groups > Molecular Microbiology Faculty of Science > Research Centres > Centre for Molecular and Structural Biochemistry
Related URLs:	https://www.scopus.com/pages/publication...
Depositing User:	LivePure Connector
Date Deposited:	26 May 2026 14:28
Last Modified:	26 May 2026 14:28
URI:	https://ueaeprints.uea.ac.uk/id/eprint/103156
DOI:	10.1073/pnas.89.18.8784

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