RegulonDB RegulonDB 9.3:Regulon Page

FadR DNA-binding transcriptional dual regulator

Synonyms: FadR-acyl-CoA, FadR
FadR, Fatty acid degradation Regulon [21] is a multifunctional dual regulator [22]that exerts negative control over the fatty acid degradative regulon [23, 24]and acetate metabolism [25] whereas it is responsible for maximal expression of unsaturated fatty acid biosynthesis [26] FadR coordinately regulates fatty acid biosynthesis and fatty acid degradation at the level of transcription [17] In this way, FadR functions as a switch between fatty acid β-oxidation and fatty acid biosynthesis [27]
FadR is a global regulator of lipid metabolism and a global regulator of fatty acid (FA) metabolism, acting both as a repressor of catabolism and an activator of anabolism, two directly opposing pathways, degradation and synthesis [2] FadR activates the fabH promoter in the absence of long-chain FA [8] Multiple promoters seem to be a common feature of FA synthesis genes [2]
FadR belongs to the GntR family [28, 29] However, Xu et al.
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Transcription factor      
TF conformation(s):
Name Conformation Type TF-Effector Interaction Type Apo/Holo Conformation Evidence (Confirmed, Strong, Weak) References
FadR Functional   Apo [BPP], [IPI] [1]
FadR-acyl-CoA Non-Functional Allosteric Holo [BPP], [IPI] [1]
Evolutionary Family: GntR
Sensing class: Using internal synthesized signals
Connectivity class: Local Regulator
Gene name: fadR
  Genome position: 1234938-1235657
  Length: 720 bp / 239 aa
Operon name: fadR
TU(s) encoding the TF:
Transcription unit        Promoter

Regulated gene(s) accA, accB, accC, accD, fabA, fabB, fabD, fabG, fabH, fabI, fadA, fadB, fadD, fadE, fadH, fadI, fadJ, fadL, fadM, fadR, iclR, sroD, uspA
Multifun term(s) of regulated gene(s) MultiFun Term (List of genes associated to the multifun term)
fatty acids and phosphatidic acid (10)
fatty acids (10)
Transcription related (2)
repressor (2)
operon (2)
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Regulated operon(s) accA, accBC, accD, fabA, fabB, fabI, fadBA, fadD-sroD, fadE, fadH, fadIJ, fadL, fadM, fadR, iclR, uspA, yceD-rpmF-plsX-fabHDG-acpP-fabF
First gene in the operon(s) accA, accB, accD, fabA, fabB, fabH, fabI, fadB, fadD, fadE, fadH, fadI, fadL, fadM, fadR, iclR, uspA
Simple and complex regulons ArcA,CRP,FadR
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Simple and complex regulatory phrases Regulatory phrase (List of promoters regulated by the phrase)

Transcription factor binding sites (TFBSs) arrangements       

  Functional conformation Function Promoter Sigma factor Central Rel-Pos Distance to first Gene Genes Sequence LeftPos RightPos Evidence (Confirmed, Strong, Weak) References
  FadR activator accAp2 nd -38.0 -333.0 accA
208280 208296 [AIBSCS], [BPP], [GEA] [2]
  FadR activator accBp2 nd -49.0 -313.0 accB, accC
3405115 3405131 [AIBSCS], [BPP], [GEA] [2]
  FadR activator accDp Sigma70 -49.0 -138.0 accD
2434056 2434072 [AIBSCS], [BPP], [GEA] [2]
  FadR activator fabAp Sigma70 -38.0 -66.0 fabA
1016528 1016544 [BCE], [GEA], [HIBSCS] [3], [4], [5], [6]
  FadR activator fabBp Sigma70 -39.0 -75.0 fabB
2441672 2441688 [BPP], [GEA], [HIBSCS] [3], [4], [7]
  FadR activator fabHp nd -38.0 -281.0 fabH, fabD, fabG
1148470 1148486 [BPP], [GEA], [HIBSCS], [SM] [8], [9]
  FadR activator fabIp nd -48.0 -130.0 fabI
1351161 1351177 [AIBSCS], [BPP], [GEA] [2]
  FadR repressor fadBp Sigma70 9.0 -34.0 fadB, fadA
4030997 4031013 [BCE], [HIBSCS] [1], [3], [5]
  FadR repressor fadDp Sigma70 -106.0 -167.0 fadD, sroD
1889905 1889921 [BPP] [3], [10], [11]
  FadR repressor fadDp Sigma70 -20.0 -81.0 fadD, sroD
1889819 1889835 [BPP] [3], [10], [11]
  FadR repressor fadEp nd 74.0 -30.0 fadE
243325 243341 [BPP], [GEA], [HIBSCS] [12]
  FadR repressor fadHp nd 4.0 -38.0 fadH
3231619 3231635 [BPP], [GEA], [HIBSCS] [13], [14]
  FadR repressor fadIp Sigma70 8.0 -35.0 fadI, fadJ
2460496 2460512 [BPP], [GEA], [HIBSCS] [15]
  FadR repressor fadLp Sigma38 -17.0 -118.0 fadL
2461180 2461196 [BCE], [BPP], [GEA], [HIBSCS] [3], [5], [11], [16], [17], [18]
  FadR repressor fadLp Sigma38 9.0 -93.0 fadL
2461205 2461221 [BCE], [BPP], [HIBSCS] [3], [5], [11], [16], [17], [18]
  FadR repressor fadMp1 Sigma24 2.0 -41.0 fadM
464353 464369 [HIBSCS] [19]
  FadR-acyl-CoA activator fadRp Sigma70 -10.0 -43.0 fadR
1234887 1234903 [AIBSCS] [9]
  FadR activator iclRp nd -54.0 -78.0 iclR
4223698 4223714 [BPP], [GEA], [SM] [5]
  FadR repressor uspAp1 Sigma70 5.0 -124.0 uspA
3639979 3639995 [BCE], [BPP], [GEA], [HIBSCS] [20]
  FadR repressor uspAp1 Sigma70 97.0 -32.0 uspA
3640071 3640087 [BCE], [BPP], [GEA], [HIBSCS] [20]

Alignment and PSSM for FadR TFBSs    

Aligned TFBS of FadR   

Position weight matrix (PWM).   
A	5	1	2	0	3	0	4	1	0	13	1	1	7	1	3	3	4	9
C	1	12	0	0	0	1	12	4	0	1	8	6	0	5	0	2	8	0
G	7	3	0	16	12	0	0	4	15	1	1	5	0	9	1	3	2	3
T	3	0	14	0	1	15	0	7	1	1	6	4	9	1	12	8	2	4

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


 [BPP] Binding of purified proteins

 [IPI] Inferred from physical interaction

 [AIBSCS] Automated inference based on similarity to consensus sequences

 [GEA] Gene expression analysis

 [BCE] Binding of cellular extracts

 [HIBSCS] Human inference based on similarity to consensus sequences

 [SM] Site mutation


 [1] DiRusso CC., Heimert TL., Metzger AK., 1992, Characterization of FadR, a global transcriptional regulator of fatty acid metabolism in Escherichia coli. Interaction with the fadB promoter is prevented by long chain fatty acyl coenzyme A., J Biol Chem. 267(12):8685-91

 [2] My L., Ghandour Achkar N., Viala JP., Bouveret E., 2015, Reassessment of the Genetic Regulation of Fatty Acid Synthesis in Escherichia coli: Global Positive Control by the Dual Functional Regulator FadR., J Bacteriol. 197(11):1862-72

 [3] DiRusso CC., Black PN., Weimar JD., 1999, Molecular inroads into the regulation and metabolism of fatty acids, lessons from bacteria., Prog Lipid Res. 38(2):129-97

 [4] Feng Y., Cronan JE., 2011, Complex binding of the FabR repressor of bacterial unsaturated fatty acid biosynthesis to its cognate promoters., Mol Microbiol. 80(1):195-218

 [5] Gui L., Sunnarborg A., LaPorte DC., 1996, Regulated expression of a repressor protein: FadR activates iclR., J Bacteriol. 178(15):4704-9

 [6] Henry MF., Cronan JE., 1992, A new mechanism of transcriptional regulation: release of an activator triggered by small molecule binding., Cell. 70(4):671-9

 [7] Campbell JW., Cronan JE., 2001, Escherichia coli FadR positively regulates transcription of the fabB fatty acid biosynthetic gene., J Bacteriol. 183(20):5982-90

 [8] My L., Rekoske B., Lemke JJ., Viala JP., Gourse RL., Bouveret E., 2013, Transcription of the Escherichia coli Fatty Acid Synthesis Operon fabHDG Is Directly Activated by FadR and Inhibited by ppGpp., J Bacteriol. 195(16):3784-95

 [9] Zhang F., Ouellet M., Batth TS., Adams PD., Petzold CJ., Mukhopadhyay A., Keasling JD., 2012, Enhancing fatty acid production by the expression of the regulatory transcription factor FadR., Metab Eng. 14(6):653-60

 [10] Black PN., DiRusso CC., Metzger AK., Heimert TL., 1992, Cloning, sequencing, and expression of the fadD gene of Escherichia coli encoding acyl coenzyme A synthetase., J Biol Chem. 267(35):25513-20

 [11] Feng Y., Cronan JE., 2012, Crosstalk of Escherichia coli FadR with global regulators in expression of fatty acid transport genes., PLoS One. 7(9):e46275

 [12] Campbell JW., Cronan JE., 2002, The enigmatic Escherichia coli fadE gene is yafH., J Bacteriol. 184(13):3759-64

 [13] Cho BK., Knight EM., Palsson BO., 2006, Transcriptional regulation of the fad regulon genes of Escherichia coli by ArcA., Microbiology. 152(Pt 8):2207-19

 [14] Feng Y., Cronan JE., 2010, Overlapping Repressor Binding Sites Result in Additive Regulation of Escherichia coli FadH by FadR and ArcA., J Bacteriol. 192(17):4289-99

 [15] Campbell JW., Morgan-Kiss RM., E Cronan J., 2003, A new Escherichia coli metabolic competency: growth on fatty acids by a novel anaerobic beta-oxidation pathway., Mol Microbiol. 47(3):793-805

 [16] Black PN., 1991, Primary sequence of the Escherichia coli fadL gene encoding an outer membrane protein required for long-chain fatty acid transport., J Bacteriol. 173(2):435-42

 [17] DiRusso CC., Metzger AK., Heimert TL., 1993, Regulation of transcription of genes required for fatty acid transport and unsaturated fatty acid biosynthesis in Escherichia coli by FadR., Mol Microbiol. 7(2):311-22

 [18] Higashitani A., Nishimura Y., Hara H., Aiba H., Mizuno T., Horiuchi K., 1993, Osmoregulation of the fatty acid receptor gene fadL in Escherichia coli., Mol Gen Genet. 240(3):339-47

 [19] Nie L., Ren Y., Schulz H., 2008, Identification and characterization of Escherichia coli thioesterase III that functions in fatty acid beta-oxidation., Biochemistry. 47(29):7744-51

 [20] Farewell A., Diez AA., DiRusso CC., Nystrom T., 1996, Role of the Escherichia coli FadR regulator in stasis survival and growth phase-dependent expression of the uspA, fad, and fab genes., J Bacteriol. 178(22):6443-50

 [21] Overath P., Pauli G., Schairer HU., 1969, Fatty acid degradation in Escherichia coli. An inducible acyl-CoA synthetase, the mapping of old-mutations, and the isolation of regulatory mutants., Eur J Biochem. 7(4):559-74

 [22] DiRusso CC., 1988, Nucleotide sequence of the fadR gene, a multifunctional regulator of fatty acid metabolism in Escherichia coli., Nucleic Acids Res. 16(16):7995-8009

 [23] Simons RW., Egan PA., Chute HT., Nunn WD., 1980, Regulation of fatty acid degradation in Escherichia coli: isolation and characterization of strains bearing insertion and temperature-sensitive mutations in gene fadR., J Bacteriol. 142(2):621-32

 [24] Simons RW., Hughes KT., Nunn WD., 1980, Regulation of fatty acid degradation in Escherichia coli: dominance studies with strains merodiploid in gene fadR., J Bacteriol. 143(2):726-30

 [25] Maloy SR., Nunn WD., 1981, Role of gene fadR in Escherichia coli acetate metabolism., J Bacteriol. 148(1):83-90

 [26] Nunn WD., Giffin K., Clark D., Cronan JE., 1983, Role for fadR in unsaturated fatty acid biosynthesis in Escherichia coli., J Bacteriol. 154(2):554-60

 [27] Xu Y., Heath RJ., Li Z., Rock CO., White SW., 2001, The FadR.DNA complex. Transcriptional control of fatty acid metabolism in Escherichia coli., J Biol Chem. 276(20):17373-9

 [28] van Aalten DM., DiRusso CC., Knudsen J., Wierenga RK., 2000, Crystal structure of FadR, a fatty acid-responsive transcription factor with a novel acyl coenzyme A-binding fold., EMBO J. 19(19):5167-77

 [29] Haydon DJ., Guest JR., 1991, A new family of bacterial regulatory proteins., FEMS Microbiol Lett. 63(2-3):291-5

 [30] Raman N., DiRusso CC., 1995, Analysis of acyl coenzyme A binding to the transcription factor FadR and identification of amino acid residues in the carboxyl terminus required for ligand binding., J Biol Chem. 270(3):1092-7

 [31] Raman N., Black PN., DiRusso CC., 1997, Characterization of the fatty acid-responsive transcription factor FadR. Biochemical and genetic analyses of the native conformation and functional domains., J Biol Chem. 272(49):30645-50

 [32] Cronan JE., Subrahmanyam S., 1998, FadR, transcriptional co-ordination of metabolic expediency., Mol Microbiol. 29(4):937-43

 [33] van Aalten DM., Knudsen J., DiRusso CC., Kokko T., Wierenga RK., 2000, Crystallization and X-ray diffraction studies of the fatty-acid responsive transcription factor FadR from Escherichia coli., Acta Crystallogr D Biol Crystallogr. 56 ( Pt 4):469-71

 [34] Cronan JE., 1997, In vivo evidence that acyl coenzyme A regulates DNA binding by the Escherichia coli FadR global transcription factor., J Bacteriol. 179(5):1819-23

 [35] Zhang Y., Gao R., Ye H., Wang Q., Feng Y., 2014, A new glimpse of FadR-DNA crosstalk revealed by deep dissection of the E. coli FadR regulatory protein., Protein Cell. 5(12):928-39

 [36] Iram SH., Cronan JE., 2005, Unexpected functional diversity among FadR fatty acid transcriptional regulatory proteins., J Biol Chem. 280(37):32148-56

 [37] Brown RN., Gulig PA., 2008, Regulation of fatty acid metabolism by FadR is essential for Vibrio vulnificus to cause infection of mice., J Bacteriol. 190(23):7633-44

 [38] Georgi T., Engels V., Wendisch VF., 2008, Regulation of L-lactate utilization by the FadR-type regulator LldR of Corynebacterium glutamicum., J Bacteriol. 190(3):963-71

 [39] Oh HY., Lee JO., Kim OB., 2012, Increase of organic solvent tolerance of Escherichia coli by the deletion of two regulator genes, fadR and marR., Appl Microbiol Biotechnol. 96(6):1619-27

 [40] Marrakchi H., Zhang YM., Rock CO., 2002, Mechanistic diversity and regulation of Type II fatty acid synthesis., Biochem Soc Trans. 30(Pt 6):1050-5