RegulonDB RegulonDB 10.8:Regulon Page

FucR DNA-binding transcriptional activator

Synonyms: FucR-L-fuculose-1-P, FucR
"Fucose regulator," FucR, acts as an activator of operons involved in fucose transport and degradation [5]. During induction by fuculose 1-phosphate, FucR binds to DNA, positively autoregulating itself and simultaneously activating transcription of the divergent fucAO operon. Expression of this operon requires growth on L-fucose or L-rhamnose under anaerobic conditions [1, 4]. The repressor gene of this operon is positioned at the 3' end of the operon itself [6]. As a member of the DeoR family, FucR features an N-terminal domain containing a putative helix-turn-helix motif [2].

Transcription factor      
TF conformation(s):
Name Conformation Type TF-Effector Interaction Type Apo/Holo Conformation Evidence (Confirmed, Strong, Weak) References
FucR Non-Functional   Apo [GEA], [IMP], [IPI] [1]
FucR-L-fuculose-1-P Functional Allosteric Holo [GEA], [HIFS], [IEP], [IMP], [IPI] [1], [2]
Evolutionary Family: DeoR
Sensing class: External sensing using transported metabolites
Connectivity class: Local Regulator
Gene name: fucR
  Genome position: 2939368-2940099
  Length: 732 bp / 243 aa
Operon name: fucPIKUR
TU(s) encoding the TF:
Transcription unit        Promoter

Regulated gene(s) fucA, fucI, fucK, fucO, fucP, fucR, fucU
Multifun term(s) of regulated gene(s) MultiFun Term (List of genes associated to the multifun term)
carbon compounds (7)
glycolate metabolism (1)
Porters (Uni-, Sym- and Antiporters) (1)
membrane (1)
Transcription related (1)
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Regulated operon(s) fucAO, fucPIKUR
First gene in the operon(s) fucA, fucP
Simple and complex regulons CRP,FucR
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 (Confirmed, Strong, Weak) References
  FucR-L-fuculose-1-P activator fucAp Sigma70 nd nd fucA, fucO nd nd [CV(GEA)], [GEA], [IMP] [3], [4]
  FucR-L-fuculose-1-P activator fucPp Sigma70 nd nd fucP, fucI, fucK, fucU, fucR nd nd [GEA] [3], [4]

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


 [GEA] Gene expression analysis

 [IMP] Inferred from mutant phenotype

 [IPI] Inferred from physical interaction

 [HIFS] Human inference of function from sequence

 [IEP] Inferred from expression pattern

 [CV(GEA)] cross validation(GEA)


 [1] Bartkus JM., Mortlock RP., 1986, Isolation of a mutation resulting in constitutive synthesis of L-fucose catabolic enzymes., J Bacteriol 165(3):710-4

 [2] Zeng G., Ye S., Larson TJ., 1996, Repressor for the sn-glycerol 3-phosphate regulon of Escherichia coli K-12: primary structure and identification of the DNA-binding domain., J Bacteriol 178(24):7080-9

 [3] Podolny V., Lin EC., Hochschild A., 1999, A cyclic AMP receptor protein mutant that constitutively activates an Escherichia coli promoter disrupted by an IS5 insertion., J Bacteriol 181(24):7457-63

 [4] Zhu Y., Lin EC., 1988, A mutant crp allele that differentially activates the operons of the fuc regulon in Escherichia coli., J Bacteriol 170(5):2352-8

 [5] Chen YM., Zhu Y., Lin EC., 1987, The organization of the fuc regulon specifying L-fucose dissimilation in Escherichia coli K12 as determined by gene cloning., Mol Gen Genet 210(2):331-7

 [6] Lu Z., Lin EC., 1989, The nucleotide sequence of Escherichia coli genes for L-fucose dissimilation., Nucleic Acids Res 17(12):4883-4