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Gene Review

trpR  -  transcriptional repressor, tryptophan-binding

Escherichia coli str. K-12 substr. MG1655

Synonyms: ECK4385, JW4356
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Disease relevance of trpR


High impact information on trpR


Chemical compound and disease context of trpR


Biological context of trpR

  • The transcription start site for trpR mRNA synthesis in vitro was shown to be 56 base pairs prior to the translation start site [1].
  • These findings and the additional observation that trp repressor inhibits transcription initiation in vitro establish that there is a functional overlap of operator and promoter sequences in the regulatory region of the trpR operon [1].
  • Additional features of the DNA sequences include a 22 base pair region upstream from the proposed structural gene which exhibits striking homology with the trp operator, thus implying that expression of the trpR gene may be under autogenous regulation [10].
  • The extent of repression varied from 300-fold for the trp operon, to sixfold for the aroH operon and threefold for the trpR operon [11].
  • A hairpin structure that could serve as a transcriptional terminator is located downstream of the slt coding region and precedes the trpR open reading frame at 99.7 min on the E. coli chromosomal map [12].

Anatomical context of trpR


Associations of trpR with chemical compounds

  • Purified trp aporepressor, when activated by L-tryptophan, protects restriction sites in this region, the presumed trpR operator, from cleavage by the respective restriction endonucleases [1].
  • In vivo the mutants have 2- to 4-fold increased levels of expression of the trp operon above the level of the trpR parental strain [14].
  • The differences in backbone chemical shifts between the two subunits within each dimer of delta 2-7 trpR reflect dimer-dimer contacts involving the helix-turn-helix domains and N-terminal residues consistent with a previously determined crystal structure [Lawson and Carey (1993) Nature, 366, 178-182] [8].
  • This tyrosine-mediated repression is trpR dependent and implies an interaction between TrpR and TyrR proteins in the presence of tyrosine [15].
  • The constitutive expression of the thr, leu, and ilv operons in mutants avr-16 and flr-9 was partly reversed in cells harboring a plasmid, which leads to elevated levels of the trpR gene product, the Trp aporepressor protein [16].

Other interactions of trpR

  • The Escherichia coli host strains, TH1, TH2, TH3 alpha, TH4 and TH5, all trpR-, rpsL- and supE-, were constructed to constitutively express a trp promoter/operator (POtrp)-driven synthetic rpsLam+ gene encoding the streptomycin sensitivity (Sms) determinant (ribosomal protein S12) [17].

Analytical, diagnostic and therapeutic context of trpR

  • The association of L-tryptophan and some of its analogs, including three conformationally restricted analogs, with trp aporepressor (apo trpR) was studied by isothermal titration microcalorimetry [18].


  1. Nucleotide sequence and expression of Escherichia coli trpR, the structural gene for the trp aporepressor. Gunsalus, R.P., Yanofsky, C. Proc. Natl. Acad. Sci. U.S.A. (1980) [Pubmed]
  2. Nucleotide sequence of the Salmonella typhimurium trpR gene. Skrypka, I., Somerville, R.L. DNA Seq. (1994) [Pubmed]
  3. Shared operator recognition specificity between Trp repressor and the repressors of bacteriophage 434. Somerville, R.L., Bogosian, G., Zeilstra-Ryalls, J.H. J. Mol. Biol. (1991) [Pubmed]
  4. Frameshifting in the expression of the E. coli trpR gene occurs by the bypassing of a segment of its coding sequence. Benhar, I., Engelberg-Kulka, H. Cell (1993) [Pubmed]
  5. Mutant Trp repressors with new DNA-binding specificities. Bass, S., Sorrells, V., Youderian, P. Science (1988) [Pubmed]
  6. Purification and characterization of trp aporepressor. Joachimiak, A., Kelley, R.L., Gunsalus, R.P., Yanofsky, C., Sigler, P.B. Proc. Natl. Acad. Sci. U.S.A. (1983) [Pubmed]
  7. Trp aporepressor production is controlled by autogenous regulation and inefficient translation. Kelley, R.L., Yanofsky, C. Proc. Natl. Acad. Sci. U.S.A. (1982) [Pubmed]
  8. Subunit-specific backbone NMR assignments of a 64 kDa trp repressor/DNA complex: a role for N-terminal residues in tandem binding. Shan, X., Gardner, K.H., Muhandiram, D.R., Kay, L.E., Arrowsmith, C.H. J. Biomol. NMR (1998) [Pubmed]
  9. Cloning and insertional inactivation of the dye (sfrA) gene, mutation of which affects sex factor F expression and dye sensitivity of Escherichia coli K-12. Buxton, R.S., Drury, L.S. J. Bacteriol. (1983) [Pubmed]
  10. DNA sequence of the E. coli trpR gene and prediction of the amino acid sequence of Trp repressor. Singleton, C.K., Roeder, W.D., Bogosian, G., Somerville, R.L., Weith, H.L. Nucleic Acids Res. (1980) [Pubmed]
  11. trp repressor interactions with the trp aroH and trpR operators. Comparison of repressor binding in vitro and repression in vivo. Klig, L.S., Carey, J., Yanofsky, C. J. Mol. Biol. (1988) [Pubmed]
  12. Murein-metabolizing enzymes from Escherichia coli: sequence analysis and controlled overexpression of the slt gene, which encodes the soluble lytic transglycosylase. Engel, H., Kazemier, B., Keck, W. J. Bacteriol. (1991) [Pubmed]
  13. High level production and rapid purification of the E. coli trp repressor. Paluh, J.L., Yanofsky, C. Nucleic Acids Res. (1986) [Pubmed]
  14. Single base-pair alterations in the Escherichia coli trp operon leader region that relieve transcription termination at the trp attenuator. Stauffer, G.V., Zurawski, G., Yanofsky, C. Proc. Natl. Acad. Sci. U.S.A. (1978) [Pubmed]
  15. Mutations in the tyrR gene of Escherichia coli which affect TyrR-mediated activation but not TyrR-mediated repression. Yang, J., Camakaris, H., Pittard, A.J. J. Bacteriol. (1993) [Pubmed]
  16. Evidence that repression mechanisms can exert control over the thr, leu, and ilv operons of Escherichia coli K-12. Johnson, D.I., Somerville, R.L. J. Bacteriol. (1983) [Pubmed]
  17. Construction and characterization of new host-vector systems for the enforcement-cloning method. Hashimoto-Gotoh, T., Tsujimura, A., Kuriyama, K., Matsuda, S. Gene (1993) [Pubmed]
  18. Thermodynamic studies of the interaction of trp aporepressor with tryptophan analogs. Hu, D.D., Eftink, M.R. Biophys. Chem. (1994) [Pubmed]
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