Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 1992 Apr 1;89(7):3140-4.
doi: 10.1073/pnas.89.7.3140.

A transcriptional silencer downstream of the promoter in the osmotically controlled proU operon of Salmonella typhimurium

D G Overdier  1 , L N Csonka
Affiliations

A transcriptional silencer downstream of the promoter in the osmotically controlled proU operon of Salmonella typhimurium

D G Overdier et al. Proc Natl Acad Sci U S A. .

Abstract

The proU operon of Salmonella typhimurium is induced by conditions of high osmolality. The cis-acting sequences that mediate osmotic control of transcription were characterized by deletion analysis. The nucleotide sequence between -60 and +274 (relative to the transcription start point) is sufficient for normal osmotic control. Deletions that removed sequences upstream of position +274 but left the promoter intact resulted in greatly increased expression from the proU promoter in the absence of osmotic stress. Thus, the transcription control region of the proU operon consists of two discrete components: (i) the promoter and (ii) a negatively acting site that overlaps the coding sequence of the first structural gene of the operon, proV. That this negative regulatory element is a transcriptional terminator or mRNA processing site was ruled out. Our results suggest that the negative regulatory element behaves as a transcriptional silencer that inhibits transcription initiation at the proU promoter in medium of low osmolality by some action at a distance. We propose several possible mechanisms for the function of this regulatory site.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Annu Rev Microbiol. 1991;45:569-606 - PubMed
    1. Cell. 1989 Apr 21;57(2):193-5 - PubMed
    1. Nature. 1990 Jul 5;346(6279):76-9 - PubMed
    1. Science. 1989 Jun 23;244(4911):1457-61 - PubMed
    1. Plasmid. 1989 Jan;21(1):31-42 - PubMed

Publication types

LinkOut - more resources