Skip to main content
Journal of Bacteriology logoLink to Journal of Bacteriology
. 1993 Jan;175(1):303–306. doi: 10.1128/jb.175.1.303-306.1993

Mutational uncoupling of the transcriptional activation function of the TyrR protein of Escherichia coli K-12 from the repression function.

J Cui 1, R L Somerville 1
PMCID: PMC196128  PMID: 8416907

Abstract

The tyrosine repressor (TyrR) protein of Escherichia coli can function either as a transcriptional enhancer or as a repressor. The structural basis for these opposite effects was analyzed in specific tyrR deletion mutants constructed in vitro. The functional behavior of the mutant TyrR proteins was evaluated in vivo by using single-copy lacZ reporter systems based on the mtr promoter (10-fold activation by wild-type TyrR protein, mediated by phenylalanine or tyrosine) or the aroF promoter (over 20-fold repression by wild-type TyrR protein, mediated by tyrosine). A mutant TyrR protein lacking amino acids 2 to 9 was completely devoid of transcriptional activation function. Five additional mutant TyrR proteins lacking progressively greater numbers of N-terminal amino acids were likewise activation defective. The mutant TyrR proteins lacking amino acid residues 2 to 9 or 2 to 19 were essentially identical to the wild-type TyrR protein in their ability to repress the aroF promoter. Three other TyrR mutant proteins, lacking up to 143 amino acid residues from the N-terminal end of the protein, retained the ability to repress the aroF promoter, to different extents, in a tyrosine-dependent manner.

Full text

PDF
303

Images in this article

Selected References

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

  1. Andrews A. E., Dickson B., Lawley B., Cobbett C., Pittard A. J. Importance of the position of TYR R boxes for repression and activation of the tyrP and aroF genes in Escherichia coli. J Bacteriol. 1991 Aug;173(16):5079–5085. doi: 10.1128/jb.173.16.5079-5085.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Bell A., Gaston K., Williams R., Chapman K., Kolb A., Buc H., Minchin S., Williams J., Busby S. Mutations that alter the ability of the Escherichia coli cyclic AMP receptor protein to activate transcription. Nucleic Acids Res. 1990 Dec 25;18(24):7243–7250. doi: 10.1093/nar/18.24.7243. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Cobbett C. S., Morrison S., Pittard J. Isolation and analysis of aroFo mutants by using an aroF-lac operon fusion. J Bacteriol. 1984 Jan;157(1):303–310. doi: 10.1128/jb.157.1.303-310.1984. [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. Cui J., Somerville R. L. Physical map location and transcriptional orientation of the tyrR gene of Escherichia coli K-12. J Bacteriol. 1992 Jun;174(11):3832–3833. doi: 10.1128/jb.174.11.3832-3833.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Drummond M. H., Contreras A., Mitchenall L. A. The function of isolated domains and chimaeric proteins constructed from the transcriptional activators NifA and NtrC of Klebsiella pneumoniae. Mol Microbiol. 1990 Jan;4(1):29–37. doi: 10.1111/j.1365-2958.1990.tb02012.x. [DOI] [PubMed] [Google Scholar]
  7. Eschenlauer A. C., Reznikoff W. S. Escherichia coli catabolite gene activator protein mutants defective in positive control of lac operon transcription. J Bacteriol. 1991 Aug;173(16):5024–5029. doi: 10.1128/jb.173.16.5024-5029.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Heatwole V. M., Somerville R. L. The tryptophan-specific permease gene, mtr, is differentially regulated by the tryptophan and tyrosine repressors in Escherichia coli K-12. J Bacteriol. 1991 Jun;173(11):3601–3604. doi: 10.1128/jb.173.11.3601-3604.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Irwin N., Ptashne M. Mutants of the catabolite activator protein of Escherichia coli that are specifically deficient in the gene-activation function. Proc Natl Acad Sci U S A. 1987 Dec;84(23):8315–8319. doi: 10.1073/pnas.84.23.8315. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Kasian P. A., Davidson B. E., Pittard J. Molecular analysis of the promoter operator region of the Escherichia coli K-12 tyrP gene. J Bacteriol. 1986 Aug;167(2):556–561. doi: 10.1128/jb.167.2.556-561.1986. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Muday G. K., Johnson D. I., Somerville R. L., Herrmann K. M. The tyrosine repressor negatively regulates aroH expression in Escherichia coli. J Bacteriol. 1991 Jun;173(12):3930–3932. doi: 10.1128/jb.173.12.3930-3932.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Ninfa A. J., Magasanik B. Covalent modification of the glnG product, NRI, by the glnL product, NRII, regulates the transcription of the glnALG operon in Escherichia coli. Proc Natl Acad Sci U S A. 1986 Aug;83(16):5909–5913. doi: 10.1073/pnas.83.16.5909. [DOI] [PMC free article] [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. Popham D. L., Szeto D., Keener J., Kustu S. Function of a bacterial activator protein that binds to transcriptional enhancers. Science. 1989 Feb 3;243(4891):629–635. doi: 10.1126/science.2563595. [DOI] [PubMed] [Google Scholar]
  15. Rosenberg A. H., Lade B. N., Chui D. S., Lin S. W., Dunn J. J., Studier F. W. Vectors for selective expression of cloned DNAs by T7 RNA polymerase. Gene. 1987;56(1):125–135. doi: 10.1016/0378-1119(87)90165-x. [DOI] [PubMed] [Google Scholar]
  16. Sarsero J. P., Wookey P. J., Pittard A. J. Regulation of expression of the Escherichia coli K-12 mtr gene by TyrR protein and Trp repressor. J Bacteriol. 1991 Jul;173(13):4133–4143. doi: 10.1128/jb.173.13.4133-4143.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Somerville R. L., Shieh T. L., Hagewood B., Cui J. S. Gene expression from multicopy T7 promoter vectors proceeds at single copy rates in the absence of T7 RNA polymerase. Biochem Biophys Res Commun. 1991 Dec 31;181(3):1056–1062. doi: 10.1016/0006-291x(91)92044-k. [DOI] [PubMed] [Google Scholar]
  18. Stock J. B., Ninfa A. J., Stock A. M. Protein phosphorylation and regulation of adaptive responses in bacteria. Microbiol Rev. 1989 Dec;53(4):450–490. doi: 10.1128/mr.53.4.450-490.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. VOGEL H. J., BONNER D. M. Acetylornithinase of Escherichia coli: partial purification and some properties. J Biol Chem. 1956 Jan;218(1):97–106. [PubMed] [Google Scholar]
  20. Weiss D. S., Batut J., Klose K. E., Keener J., Kustu S. The phosphorylated form of the enhancer-binding protein NTRC has an ATPase activity that is essential for activation of transcription. Cell. 1991 Oct 4;67(1):155–167. doi: 10.1016/0092-8674(91)90579-n. [DOI] [PubMed] [Google Scholar]
  21. Whipp M. J., Pittard A. J. Regulation of aromatic amino acid transport systems in Escherichia coli K-12. J Bacteriol. 1977 Nov;132(2):453–461. doi: 10.1128/jb.132.2.453-461.1977. [DOI] [PMC free article] [PubMed] [Google Scholar]

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

RESOURCES