>Effectors: molecules and conditions (temperature, pH...)
>2|P34000|HTH-type transcriptional regulator acrR (Potential acrAB operon repressor)|Escherichia coli O6|TetR
General stress consitions increased transcription of acrR even more strongly than that of acrAB.
>9|Q9ZN78|A-factor receptor protein (A-factor binding protein)|Streptomyces griseus|TetR
A-factor (2-isocapryoyl-3R-hydroxymethyl-gamma-butyrolactone).
>14|P11765|Arabinose operon regulatory protein|Citrobacter freundii|AraC
Arabinose.
>15|P03021|Arabinose operon regulatory protein|Escherichia coli O157:H7|AraC
L-arabinose.
>16|P07642|Arabinose operon regulatory protein|Erwinia chrysanthemi|AraC
Arabinose.
>17|P03022|Arabinose operon regulatory protein|Salmonella typhimurium|AraC
Arabinose.
>25|P17446|HTH-type transcriptional regulator betI|Escherichia coli|TetR
The bet genes are regulated by three external stimuli: choline, oxygen and osmotic stress.
>35|P43506|HTH-type transcriptional repressor Bm3R1|Bacillus megaterium|TetR
Barbiturates, peroxisome proliferators, hypolipidemic drugs, non-steroidal anti-inflammatory compounds, polyunsaturated fatty acids, the branched-chain fatty acid, phytanic acid, all abolish the binding of Bm3R1 to its DNA regulatory sequences and this allows transcription to proceed through the Bm3R1 and P450BM-3 coding sequences.
It seems that barbiturates and barbiturate analogs are capable to be inducers because of their ability to mimic fatty acid signalling compounds but they are not recognaised as substrates by P450 enzymes. The endogenous inducer(s) is yet unidentified.
The most potent inhibitor of Bm3R1 DNA binding in vitro are polyunsaturated fatty acids (PUFA) and they binds directly to Bm3R1 and are substrates for P450BM-3, being metabolised to a less potent inhibitor.
>37|P26950|F1 operon positive regulatory protein|Yersinia pestis|AraC
Temperature. Bacteria are encapsulated at 37º C but not when they are cultured at 28ºC.
>39|P17410|HTH-type transcriptional regulator chbR (Chb operon repressor)|Escherichia coli|AraC
N,N'-diacetylchitobiose (GlcNAc)2 induces the cel (chb) operon.
>42|P10805|Porin thermoregulatory protein envY|Escherichia coli|AraC
Temperature-dependent.
>43|P36547|HTH-type transcriptional regulator eutR (Ethanolamine operon regulatory protein)|Escherichia coli|AraC
EutR probably binds ethanolamine and vitamin B12 as effectors.
>44|Q9ZFU7|HTH-type transcriptional regulator eutR (Ethanolamine operon regulatory protein)|Salmonella typhimurium|AraC
Probably ethanolamine and vitamin B12.
>45|P26993|Exoenzyme S synthesis regulatory protein exsA|Pseudomonas aeruginosa|AraC
Maximal exoenzyme S production was achieved through the growth of P. aeruginosa in medium containing low concentrations of cations.
>61|P31778|Regulatory protein hrpB|Ralstonia solanacearum|AraC
hrpB is induced in minimal medium by an unidentified environmental signal or a trans-activator product.
>69|O33813|Lactose operon transcription activator|Staphylococcus xylosus|AraC
Lactose. Lactose transport as well as beta-galactosidase activity are inducible when lactose is added  to the growth medium. Inducibility depends on a functional gene, lacR.
>70|P28808|Thermoregulatory protein lcrF|Yersinia pestis|AraC
Temperature. mRNA secondary structure predictions suggest that the lcrF Shine-Dalgarno sequence is sequestered in a stem loop. At high temperatures the stem-loop melts down and this leads to an improved efficiency in translation.
>72|P21308|HTH-type transcriptional regulator luxR|Vibrio harveyi|TetR
Stimulation of luminescence mediated by LuxR did not exhibit cell density-dependent modulation of luminescence, nor did it responds to exogenously added autoinducer.
Density-dependent expression of luminescence in Vibrio harveyi is regulated by the concentration of two extracellular signals molecules, autoinducers (AI-1 and AI-2).
AI-1 is the N-(3-hydroxybutanoyl)-homoserine lactone.
The chemical structure of AI-2 is not known, however is not an homoserine lactone.
The luxL and luxM gene products are involved in the synthesis of AI-1.
Synthesis of AI-2 is dependent on the gene luxS product.
>78|P10411|Melibiose operon regulatory protein|Escherichia coli O6|AraC
Melibiose.
>80|P28809|MmsAB operon regulatory protein|Pseudomonas aeruginosa|AraC
The MmsAB operon is induced when Pseudomonas aeruginosa is grown on medium containing valine as the sole carbon source.
>82|P39897|HTH-type transcriptional regulator mtrR|Neisseria gonorrhoeae|TetR
The mtrCDE encoded efflux pump system is inducible at transcriptional level by exposure to hydrophobic antimicrobial agents, but this induction is MtrR-independent.
>83|Q04642|Transcriptional regulator mxiE|Shigella flexneri|AraC
MxiE is probably regulated by temperature.
>90|P72171|Ornithine utilization regulator|Pseudomonas aeruginosa|AraC
Probably ornithine.
>93|P40883|Regulatory protein pchR|Pseudomonas aeruginosa|AraC
PchR gene expression is inducible by iron limitation and by pyochelin.
>97|Q05587|Regulatory protein pocR|Salmonella typhimurium|AraC
Propanediol.
>100|P23217|HTH-type transcriptional regulator qacR|Staphylococcus aureus subsp. aureus Mu50|TetR
QacR interacts directly with structurally dissimilar inducing compounds that are substrates of the QacA multidrug efflux pump: dyes, biguanidines, diamines and quaternary-ammonium compounds (QACs).
The crystal structure reveal that QacR binds one rhodamine 6G molecule per dimer.
>108|P09378|L-rhamnose operon transcriptional activator rhaR|Escherichia coli|AraC
L-rhamnose.
>110|P09377|L-rhamnose operon regulatory protein rhaS|Escherichia coli|AraC
L-rhamnose. RhaS binding and activation of RhaBAD occurs only in the presence of L-rhamnose.
>114|P16114|Regulatory protein rns|Escherichia coli|AraC
None of the virulence regulators of this family have been found to respond to an effector molecule.
>115|P27292|Right origin-binding protein|Escherichia coli O157:H7|AraC
The structural similarity of Rob's C-terminal domain and the GalT ligand binding pocket suggest a model in which the C-terminal domain of Rob might bind to an effector molecule that regulates Rob transcriptional activity.
>122|P39885|HTH-type transcriptional regulator tcmR (Tetracenomycin C transcriptional repressor)|Streptomyces glaucescens|TetR
Transcription of tcmA and tcmR genes are inducible by tetracenomycin C in vivo.
>124|P03038|Tetracycline repressor protein class A from transposon 1721|Escherichia coli|TetR
Expression of the tet genes is induced by a tetracycline-metal complex, [Tc-Mg]+.
>126|P04483|Tetracycline repressor protein class B from transposon Tn10|Escherichia coli|TetR
Expression of the tet genes is induced by a tetracycline-metal complex, [Tc-Mg]+.
>127|P03039|Tetracycline repressor protein class C|Escherichia coli|TetR
Expression of the tet genes is induced by a tetracycline-metal complex, [Tc-Mg]+.
>128|P09164|Tetracycline repressor protein class D|Escherichia coli|TetR
Expression of the tet genes is induced by a tetracycline-metal complex, [Tc-Mg]+.
>138|P43462|Probable thc operon regulatory protein|Rhodococcus erythropolis|AraC
Expression of thcB was 10-fold higher in the presence of the herbicide EPTC (s-ethyl dipropylthiocarbamate). ThcB is induced by thiocarbamate herbicides and to a lower extent by atrazine.
>145|P32326|Urease operon transcriptional activator|Escherichia coli|AraC
Urea.
>146|Q02458|Urease operon transcriptional activator|Proteus mirabilis|AraC
Urea.
>151|Q04248|Virulence regulon transcriptional activator virF|Shigella dysenteriae|AraC
Temperature controls expression of VirF. The VirF promoter fragment contains two H-NS sites, and undergoes a specific and temperature-dependent conformational transition around 32ºC.
>166|P07859|XylDLEGF operon transcriptional activator|Pseudomonas putida|AraC
The XylS protein is activated by benzoates, alkylbenzoates and chlorobenzoates.
>167|Q04710|XylDLEGF operon transcriptional activator 1|Pseudomonas putida|AraC
Benzoate and benzoates substituted at position 3 with chloro or a methyl group, and 2,3-dimethyl-benzoate.
>170|Q05335|XYLDLEGF operon transcriptional activator 3|Pseudomonas putida|AraC
3-methylbenzoate.
>253|O33453|CymR|Pseudomonas putida|TetR
p-cumate induces both the cym and cmt operons, whereas p-cymene is not an inducer.
>258|O52834|AlcR (Alcaligin siderophore system regulator)|Bordetella bronchiseptica|AraC
AlcR responds to the presence of the cognate siderophore or iron compound.
>259|O52846|XylS/AraC transcriptional regulator|Bacillus megaterium|AraC
Lactose.
>263|O68442|Regulatory protein|Agrobacterium tumefaciens|TetR
The isoflavonoid coumestrol induces ifeA expression.
>269|O70020|IcaR|Staphylococcus epidermidis|TetR
Well known biofilm-promoting growth conditions are salt and ethanol.
Activation of ica operon by ethanol is icaR dependent.
The induction of ica operon expression by NaCl-glucose is small but significant. This induction icaR independent and is rsbU/sigB dependent.
>279|P72312|Nitrilase regulator|Rhodococcus rhodochrous|AraC
Probably isovaleronitrilo.
>335|Q8VVJ2|TetR protein|Corynebacterium glutamicum|TetR
Tetracylcine.
>387|Q46985|Regulator of the 4HPA-hydroxylase operon|Escherichia coli|AraC
4-hydroxyphenylacetic acid, 3-hydroxyphenylacetic acid, or phenylacetate.
>388|Q47074|BfpT protein|Escherichia coli|AraC
Expression of the bundle-forming pilus (BFP) of enteropathogenic Escherichia coli is regulated by the growth phase, temperature, calcium and ammonium.
>393|Q51597|Cam repressor|Pseudomonas putida|TetR
D-camphor and D-3-bromocamphor, adamantane, 2-adamantane, 5-exo-hydroxycamphor and 2,5-diketokanphane are inducers of the cam system.
>407|Q56790|HrpXv|Xanthomonas campestris pv. vesicatoria|AraC
In vitro in XVM medium (replacing the tomato conditioned medium TCM) induces HrpXv.
>416|Q60011|Virginiae butanolide receptor|Streptomyces virginiae|TetR
The butyrolactones autoregulators named virginiae butanolides (VBs) are the autoinducers that bind to BarA.
>840|Q9AIQ9|IcaR|Staphylococcus caprae|TetR
Well known biofilm-promoting growth conditions are salt and ethanol.
>841|Q9AIU0|Regulatory protein TtgR|Pseudomonas putida|TetR
It has been shown that the hydrophobic antibiotics chloramphenicol and tetracycline act as inducers.
>844|Q9AJL5|VarR|Streptomyces virginiae|TetR
The binding of VarR to the 5’ upstream region of varS is specifically inhibited by the antibiotic virginiamycin S.
>852|Q9ANS7|LuxT|Vibrio harveyi|TetR
Density-dependent expression of luminescence in Vibrio harveyi is regulated by the concentration of two extracellular signals molecules, autoinducers (AI-1 and AI-2).
AI-1 is the N-(3-hydroxybutanoyl)-homoserine lactone.
The chemical structure of AI-2 is not known, however is not an homoserine lactone.
The luxL and luxM gene products are involved in the synthesis of AI-1.
Synthesis of AI-2 is dependent on the gene luxS product.
>862|Q9EVJ6|Repressor protein MphR(A)|Escherichia coli|TetR
The 14-member ring macrolides, such as erythromycin and oleandomycin, are inducers for the inhibition of the binding of MphR(A) to its operator.
>866|Q9F0Y2|Pip|Streptomyces coelicolor|TetR
Pristinamycin I (PI) is the ligang of Pip.
It seems there are an equimolar binding stoichiometry between the native protein monomer and pristinamycin I (PI).
>879|Q9F6W0|CasR|Rhizobium etli|TetR
The casA gene is expressed on the roots of Phaseolus vulgaris plants, in the infection threads, and inside the bacteroids but not under the free-living conditions, suggesting that the inducing compound is plant derived.
>897|Q9K4R5|EbdR protein|Pseudomonas putida|AraC
The ebd genes appear to be preferentially induced by ethylbenzene.
>921|Q9L7Y6|BenR|Pseudomonas putida|AraC
Benzoate.
>959|Q9R2F3|Xyls/AraC-type transcriptional activator|Acinetobacter sp. NCIMB9871|AraC
Cyclohexanone induces chnB expression.
>963|Q9R9T9|Efflux pump regulator SrpR|Pseudomonas putida|TetR
srpR forms a gene cluster with srpS and both are putative regulators of the solvent-resistance pump SrpABC expression of this pump is induced by toluene.
Compounds that are capable of inducing expression of the srpABC genes include aromatic and aliphatic solvents and alcohols. General stress conditions such as pH, temperature, NaCl, or the presence of organic acids do not induce srp transcription.
The srpABC operon is induced solely by solvent stress.
>983|Q9RPK9|TarA|Streptomyces tendae|TetR
The specific gamma-butyrolactone inducing nikkomycin production in Streptomyces tendae has not been found.
>988|Q9S166|AdpA|Streptomyces griseus|AraC
The A-factor (2-isocapryloyl-3R-hydroxymethyl-gamma-butyrolactone) at an extremely low concentration triggers streptomycin production and aerial mycelium formation in Streptomyces griseus. The A-factor induces the expression of the A-factor-dependent transcriptional activator AdpA.
>995|Q9WW32|MtrA|Neisseria gonorrhoeae|AraC
Triton X-100, which is a hydrophobic detergent, at sublethal concentrations and the structurally related spermicide nonoxynol-9 induce the mtrCDE efflux pump operon.
>998|Q9X421|Xylose regulatory protein|Lactococcus lactis subsp. lactis|AraC
Xylose metabolism is induced by xylose, mediated via XylR.
>1012|Q9XCC7|Gamma-butyrolactone receptor protein TylP|Streptomyces fradiae|TetR
tylP is a receptor for one o more gamma-butyrolactones.
>1368|O30507|Arginine regulatory protein (Transcriptional regulator ArgR) (ArgR regulatory protein)|Pseudomonas aeruginosa|AraC
ArgR synthesis is induced by exogenous arginine.
The aot operon is strongly induced by arginine and this effect is mediated by ArgR.
Expression of the first gene of the aru operon, aruC, is initiated from an arginine-inducible promoter.
Transcription of gdhB is initiated from an arginine-inducible promoter.
>1369|O31249|Transcriptional regulator of XylS /AraC family (XylS/AraC family)|Acinetobacter sp. ADP1|AraC
AlkR requires the presence of an appropriate effector molecule to activate alkM expression. AlkR effectors can be a great variety of medium- and long-length chain alkanes with a clear cut-off between the inducer, heptane, and the noninducer hexane.
AlkM is the only one out of five genes that has been characterized as necessary for alkane degradation.
AlkM is induced about 100-fold by hexadecane in the stationary phase.
>1386|O52066|AlcR (Transcriptional regulator)|Bordetella pertussis|AraC
AlcR responds to the presence of the cognate siderophore or to iron compounds.
>1431|O86852|Gamma-butyrolactone binding protein|Streptomyces coelicolor|TetR
It is the gamma-butyrolactone, SCB1, or (2R,3R,1’R)-2-(1’-hydroxy-6-methylheptyl)-3-hydroxymethylbutanolide.
>4308|Q9JN89|Hypothetical protein mmfR (Putative lactone-dependent transcriptional regulator (TetR-family), MmfR)|Streptomyces coelicolor|TetR
A putative gamma-butyrolactone synthetized by the MmfL protein may be the ligand recognized by the MmfR regulatory protein.
>5460|15928251|ica operon transcriptional regulator IcaR|Staphylococcus aureus subsp. aureus N315|TetR
Several known stimuli induce PNAG production in vitro including elevated glucose, high osmolarity, low levels of ethanol, iron restriction and oxygen depravation.
>6853|19552090|transcriptional regulator|Corynebacterium glutamicum ATCC 13032|TetR
Nitrogen level in the medium controls the DNA binding activity of AmtR. When cells are grown under nitrogen excess, AmtR is bound to its binding sites. During nitrogen starvation, AmtR separates from its binding sites.
>6871|19554126|transcriptional regulator|Corynebacterium glutamicum ATCC 13032|TetR
L-methionine.
>9416|O24741|FarA|Streptomyces sp. FRI-5|TetR
IM-2, [(2R,3R,1’R)-2-(1’-hydroxybutyl)-3-hydroxymethyl gamma-butanolide] is present in streptomyces sp. strain FRI-5 as a butyrolactone autoregulator which triggers the production of a blue pigment and the nucleoside antibiotics showdomycin and minimycin at a concentration of 0.6 ng/ml, throughout binding to FarA.
>9417|P13225|Virulence regulon transcriptional activator virF|Yersinia enterocolitica|AraC
Temperature (37ºC). Transcription of the yop, yadA, ysc and virF genes is controlled by temperature.