Skip to main content
PMC home page
Journal of Bacteriology logoLink to Journal of Bacteriology
. 1997 Jul;179(13):4206–4212. doi: 10.1128/jb.179.13.4206-4212.1997

Promoters and transcripts associated with the aroP gene of Escherichia coli.

P Wang 1, J Yang 1, A J Pittard 1
PMCID: PMC179240  PMID: 9209034

Abstract

Analysis of in vitro transcriptional events initiating within the region immediately upstream of the aroP coding region has revealed the presence of three promoters, P1, P2, and P3. Both P1 and P2 give rise to mRNA encoding the AroP protein, whereas P3 initiates transcription in the opposite direction. Both P1 and P3 contain UP elements which contribute to promoter strength. Regulation of expression from these three promoters has been examined in vitro by using supercoiled DNA templates and in vivo by using lacZ transcriptional fusions and specific promoter mutants. Expression from P2 is partially repressed by TyrR alone both in vitro and in vivo. Addition of the aromatic amino acid tyrosine, phenylalanine, or tryptophan further increases this repression. P1 is not repressed by TyrR alone but is repressed in vivo in the presence of phenylalanine, tyrosine, or tryptophan. This also occurs in vitro but requires Ca2+ ions in the reaction mixture for its demonstration. Under these conditions, transcription from P3 is enhanced by TyrR protein with phenylalanine, tyrosine, or tryptophan. However, we were unable to demonstrate P3 expression in vivo. Under repressing conditions, there is no production of truncated RNA molecules (from P1), which would be expected if repression involved a roadblock mechanism.

Full Text

The Full Text of this article is available as a PDF (687.8 KB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Brown K. D. Formation of aromatic amino acid pools in Escherichia coli K-12. J Bacteriol. 1970 Oct;104(1):177–188. doi: 10.1128/jb.104.1.177-188.1970. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Chye M. L., Guest J. R., Pittard J. Cloning of the aroP gene and identification of its product in Escherichia coli K-12. J Bacteriol. 1986 Aug;167(2):749–753. doi: 10.1128/jb.167.2.749-753.1986. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Chye M. L., Pittard J. Transcription control of the aroP gene in Escherichia coli K-12: analysis of operator mutants. J Bacteriol. 1987 Jan;169(1):386–393. doi: 10.1128/jb.169.1.386-393.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Cornish E. C., Argyropoulos V. P., Pittard J., Davidson B. E. Structure of the Escherichia coli K12 regulatory gene tyrR. Nucleotide sequence and sites of initiation of transcription and translation. J Biol Chem. 1986 Jan 5;261(1):403–410. [PubMed] [Google Scholar]
  5. Hawley D. K., McClure W. R. Compilation and analysis of Escherichia coli promoter DNA sequences. Nucleic Acids Res. 1983 Apr 25;11(8):2237–2255. doi: 10.1093/nar/11.8.2237. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. He B., Smith J. M., Zalkin H. Escherichia coli purB gene: cloning, nucleotide sequence, and regulation by purR. J Bacteriol. 1992 Jan;174(1):130–136. doi: 10.1128/jb.174.1.130-136.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. He B., Zalkin H. Repression of Escherichia coli purB is by a transcriptional roadblock mechanism. J Bacteriol. 1992 Nov;174(22):7121–7127. doi: 10.1128/jb.174.22.7121-7127.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Honoré N., Cole S. T. Nucleotide sequence of the aroP gene encoding the general aromatic amino acid transport protein of Escherichia coli K-12: homology with yeast transport proteins. Nucleic Acids Res. 1990 Feb 11;18(3):653–653. doi: 10.1093/nar/18.3.653. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Igarashi K., Hanamura A., Makino K., Aiba H., Aiba H., Mizuno T., Nakata A., Ishihama A. Functional map of the alpha subunit of Escherichia coli RNA polymerase: two modes of transcription activation by positive factors. Proc Natl Acad Sci U S A. 1991 Oct 15;88(20):8958–8962. doi: 10.1073/pnas.88.20.8958. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Igarashi K., Ishihama A. Bipartite functional map of the E. coli RNA polymerase alpha subunit: involvement of the C-terminal region in transcription activation by cAMP-CRP. Cell. 1991 Jun 14;65(6):1015–1022. doi: 10.1016/0092-8674(91)90553-b. [DOI] [PubMed] [Google Scholar]
  11. Kieny M. P., Lathe R., Lecocq J. P. New versatile cloning and sequencing vectors based on bacteriophage M13. Gene. 1983 Dec;26(1):91–99. doi: 10.1016/0378-1119(83)90039-2. [DOI] [PubMed] [Google Scholar]
  12. MONOD J., COHEN-BAZIRE G., COHN M. Sur la biosynthèse de la beta-galactosidase (lactase) chez Escherichia coli; la spécificité de l'induction. Biochim Biophys Acta. 1951 Nov;7(4):585–599. doi: 10.1016/0006-3002(51)90072-8. [DOI] [PubMed] [Google Scholar]
  13. Pittard A. J., Davidson B. E. TyrR protein of Escherichia coli and its role as repressor and activator. Mol Microbiol. 1991 Jul;5(7):1585–1592. doi: 10.1111/j.1365-2958.1991.tb01904.x. [DOI] [PubMed] [Google Scholar]
  14. Praszkier J., Wilson I. W., Pittard A. J. Mutations affecting translational coupling between the rep genes of an IncB miniplasmid. J Bacteriol. 1992 Apr;174(7):2376–2383. doi: 10.1128/jb.174.7.2376-2383.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Ross W., Gosink K. K., Salomon J., Igarashi K., Zou C., Ishihama A., Severinov K., Gourse R. L. A third recognition element in bacterial promoters: DNA binding by the alpha subunit of RNA polymerase. Science. 1993 Nov 26;262(5138):1407–1413. doi: 10.1126/science.8248780. [DOI] [PubMed] [Google Scholar]
  16. Sanger F., Nicklen S., Coulson A. R. DNA sequencing with chain-terminating inhibitors. Proc Natl Acad Sci U S A. 1977 Dec;74(12):5463–5467. doi: 10.1073/pnas.74.12.5463. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Wang P., Yang J., Lawley B., Pittard A. J. Repression of the aroP gene of Escherichia coli involves activation of a divergent promoter. J Bacteriol. 1997 Jul;179(13):4213–4218. doi: 10.1128/jb.179.13.4213-4218.1997. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Wek R. C., Hatfield G. W. Examination of the internal promoter, PE, in the ilvGMEDA operon of E. coli K-12. Nucleic Acids Res. 1986 Mar 25;14(6):2763–2777. doi: 10.1093/nar/14.6.2763. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Yang J., Ganesan S., Sarsero J., Pittard A. J. A genetic analysis of various functions of the TyrR protein of Escherichia coli. J Bacteriol. 1993 Mar;175(6):1767–1776. doi: 10.1128/jb.175.6.1767-1776.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Journal of Bacteriology are provided here courtesy of American Society for Microbiology (ASM)

RESOURCES