RegulonDB RegulonDB 11.1:Regulon Page

TrpR DNA-binding transcriptional repressor

Synonyms: TrpR, TrpR-L-tryptophan
TrpR, "tryptophan (trp) transcriptional repressor," negatively regulates expression of the trp regulon in response to intracellular levels of tryptophan [12, 14]. The TrpR regulon is involved in tryptophan biosynthesis, transport, and regulation. This regulon partially overlaps with the TyrR regulon, since expression of several genes is regulated by TrpR and TyrR, the transcriptional regulator of the TyrR regulon [7, 9, 10] TrpR represses transcription by interfering with the ability of RNA polymerase to interact with the promoter [14] The aporepressor is activated as a DNA-binding protein by noncooperative binding of two L-tryptophan molecules to the homodimer [14, 15, 16] The consensus sequence for TrpR is described as two symmetrically arranged half-sites with the sequence GNACT separated by a spacer of 8 bp [5] Nonspecific sequences appear to assist TrpR binding to the specific site, because it was observed, by footprinting assay, that the affinity of the specific site increased when the length of sequence used in the experiment was longer [13]. X-ray crystallography of the aporepressor [17] the holorepressor [18] and repressor bound to the operator oligonucleotide [19]as well as NMR studies of the repressor and aporepressor in solution [20]and bound to an operator oligonucleotide [21]reveal that the small 25-kDa protein belongs to the helix-turn-helix (HTH) family.
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Transcription factor      
TF conformation(s):
Name Conformation Type TF-Effector Interaction Type Apo/Holo Conformation Evidence Confidence level (C: Confirmed, S: Strong, W: Weak) References
TrpR Non-Functional   Apo nd nd nd
TrpR-L-tryptophan Functional Allosteric Holo nd nd nd
Evolutionary Family: TrpR
TFBs length: 18
Sensing class: Sensing external and internal signals
Connectivity class: Local Regulator
Gene name: trpR
  Genome position: 4632760-4633086
  Length: 327 bp / 108 aa
Operon name: trpR
TU(s) encoding the TF:
Transcription unit        Promoter

Regulated gene(s) aroH, aroL, aroM, mtr, trpA, trpB, trpC, trpD, trpE, trpL, trpR, yaiA
Multifun term(s) of regulated gene(s) MultiFun Term (List of genes associated to the multifun term)
tryptophan (9)
chorismate (1)
Porters (Uni-, Sym- and Antiporters) (1)
membrane (1)
Transcription related (1)
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Regulated operon(s) aroH, aroL-yaiA-aroM, mtr, trpLEDCBA, trpR
First gene in the operon(s) aroH, aroL, mtr, trpL, trpR
Simple and complex regulons HU,IHF,TrpR,TyrR
Simple and complex regulatory phrases Regulatory phrase (List of promoters regulated by the phrase)

Transcription factor regulation    

Transcription factor binding sites (TFBSs) arrangements

  Functional conformation Function Promoter Sigma factor Central Rel-Pos Distance to first Gene Genes Sequence LeftPos RightPos Evidence Confidence level (C: Confirmed, S: Strong, W: Weak) References
  TrpR-L-tryptophan repressor aroHp1 Sigma70 -37.5 -154.5 aroH
  TrpR-L-tryptophan repressor aroHp1 Sigma70 -29.5 -146.5 aroH
  TrpR-L-tryptophan repressor aroLp1 Sigma70 48.5 -77.5 aroL, yaiA, aroM
  TrpR-L-tryptophan repressor aroLp1 Sigma70 56.5 -69.5 aroL, yaiA, aroM
  TrpR-L-tryptophan repressor mtrp2 Sigma70 -19.5 -62.5 mtr
  TrpR-L-tryptophan repressor mtrp2 Sigma70 -11.5 -54.5 mtr
  TrpR-L-tryptophan repressor trpLp Sigma70 -19.5 -45.5 trpL, trpE, trpD, trpC, trpB, trpA
  TrpR-L-tryptophan repressor trpLp Sigma70 -11.5 -37.5 trpL, trpE, trpD, trpC, trpB, trpA
  TrpR-L-tryptophan repressor trpLp Sigma70 -3.5 -29.5 trpL, trpE, trpD, trpC, trpB, trpA
  TrpR-L-tryptophan repressor trpRp Sigma70 -0.5 -56.5 trpR

Alignment and PSSM for TrpR TFBSs    

Aligned TFBS of TrpR   

Position weight matrix (PWM). TrpR matrix-quality result   
A	4	1	1	4	0	1	0	3	6	1	0	6	0	0	2	2	4	2	0	5	0
C	0	3	2	1	1	3	0	0	0	5	1	0	0	0	0	3	0	3	0	0	0
G	1	1	0	0	3	0	5	0	0	0	1	0	6	0	1	0	2	0	1	1	6
T	1	1	3	1	2	2	1	3	0	0	4	0	0	6	3	1	0	1	5	0	0

;	consensus.strict             	actagcGaACtAGTtcactaG
;	consensus.strict.rc          	CTAGTGAACTAGTTCGCTAGT
;	consensus.IUPAC              	acyakyGwACtAGTwmrmtaG
;	consensus.IUPAC.rc           	CTAKYKWACTAGTWCRMTRGT
;	consensus.regexp             	ac[ct]a[gt][ct]G[at]ACtAGT[at][ac][ag][ac]taG
;	consensus.regexp.rc          	CTA[GT][CT][GT][AT]ACTAGT[AT]C[AG][AC]T[AG]GT

PWM logo   


Evolutionary conservation of regulatory elements    
     Note: Evolutionary conservation of regulatory interactions and promoters is limited to gammaproteobacteria.
TF-target gene evolutionary conservation
Promoter-target gene evolutionary conservation


 [1] Grove CL., Gunsalus RP., 1987, Regulation of the aroH operon of Escherichia coli by the tryptophan repressor., J Bacteriol 169(5):2158-64

 [2] Jeeves M., Evans PD., Parslow RA., Jaseja M., Hyde EI., 1999, Studies of the Escherichia coli Trp repressor binding to its five operators and to variant operator sequences., Eur J Biochem 265(3):919-28

 [3] Klig LS., Carey J., Yanofsky C., 1988, trp repressor interactions with the trp aroH and trpR operators. Comparison of repressor binding in vitro and repression in vivo., J Mol Biol 202(4):769-77

 [4] Kumamoto AA., Miller WG., Gunsalus RP., 1987, Escherichia coli tryptophan repressor binds multiple sites within the aroH and trp operators., Genes Dev 1(6):556-64

 [5] Yang J., Gunasekera A., Lavoie TA., Jin L., Lewis DE., Carey J., 1996, In vivo and in vitro studies of TrpR-DNA interactions., J Mol Biol 258(1):37-52

 [6] Heatwole VM., Somerville RL., 1992, Synergism between the Trp repressor and Tyr repressor in repression of the aroL promoter of Escherichia coli K-12., J Bacteriol 174(1):331-5

 [7] Lawley B., Pittard AJ., 1994, Regulation of aroL expression by TyrR protein and Trp repressor in Escherichia coli K-12., J Bacteriol 176(22):6921-30

 [8] Cho BK., Federowicz S., Park YS., Zengler K., Palsson BO., 2011, Deciphering the transcriptional regulatory logic of amino acid metabolism., Nat Chem Biol 8(1):65-71

 [9] Heatwole VM., Somerville RL., 1991, The tryptophan-specific permease gene, mtr, is differentially regulated by the tryptophan and tyrosine repressors in Escherichia coli K-12., J Bacteriol 173(11):3601-4

 [10] Sarsero JP., Wookey PJ., Pittard AJ., 1991, Regulation of expression of the Escherichia coli K-12 mtr gene by TyrR protein and Trp repressor., J Bacteriol 173(13):4133-43

 [11] Kinebuchi T., Shimamoto N., 2021, One-dimensional diffusion of TrpR along DNA enhances its affinity for the operator by chemical ratchet mechanism., Sci Rep 11(1):4255

 [12] Gunsalus RP., Yanofsky C., 1980, Nucleotide sequence and expression of Escherichia coli trpR, the structural gene for the trp aporepressor., Proc Natl Acad Sci U S A 77(12):7117-21

 [13] Shimamoto N., Toda M., Nara S., Komatsuzaki T., Kamagata K., Kinebuchi T., Tomizawa JI., 2020, Dependence of DNA length on binding affinity between TrpR and trpO of DNA., Sci Rep 10(1):15624

 [14] Squires CL, Lee FD, Yanofsky C, 1975, Interaction of the trp repressor and RNA polymerase with the trp operon., J Mol Biol, 92(1):93 10.1016/0022-2836(75)90093-5

 [15] Lane AN, 1986, The interaction of the trp repressor from Escherichia coli with L-tryptophan and indole propanoic acid., Eur J Biochem, 157(2):405 10.1111/j.1432-1033.1986.tb09682.x

 [16] Marmorstein RQ, Joachimiak A, Sprinzl M, Sigler PB, 1987, The structural basis for the interaction between L-tryptophan and the Escherichia coli trp aporepressor., J Biol Chem, 262(10):4922 None

 [17] Zhang RG., Joachimiak A., Lawson CL., Schevitz RW., Otwinowski Z., Sigler PB., 1987, The crystal structure of trp aporepressor at 1.8 A shows how binding tryptophan enhances DNA affinity., Nature 327(6123):591-7

 [18] Schevitz RW, Otwinowski Z, Joachimiak A, Lawson CL, Sigler PB, 1985, The three-dimensional structure of trp repressor., Nature, 317(6040):782 10.1038/317782a0

 [19] Otwinowski Z, Schevitz RW, Zhang RG, Lawson CL, Joachimiak A, Marmorstein RQ, Luisi BF, Sigler PB, 1988, Crystal structure of trp repressor/operator complex at atomic resolution., Nature, 335(6188):321 10.1038/335321a0

 [20] Zhao D, Arrowsmith CH, Jia X, Jardetzky O, 1993, Refined solution structures of the Escherichia coli trp holo- and aporepressor., J Mol Biol, 229(3):735 10.1006/jmbi.1993.1076

 [21] Ramesh V, Frederick RO, Syed SE, Gibson CF, Yang JC, Roberts GC, 1994, The interactions of Escherichia coli trp repressor with tryptophan and with an operator oligonucleotide. NMR studies using selectively 15N-labelled protein., Eur J Biochem, 225(2):601 10.1111/j.1432-1033.1994.00601.x

 [22] Tripet BP, Goel A, Copie V, 2011, Internal dynamics of the tryptophan repressor (TrpR) and two functionally distinct TrpR variants, L75F-TrpR and A77V-TrpR, in their l-Trp-bound forms., Biochemistry, 50(23):5140 10.1021/bi200389k