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AscG DNA-binding transcriptional repressor

Synonyms: AscG
The AscG, "Arbutin-salicin-cellibiose," transcriptional regulator represses the expression of a cryptic operon (ascFB) whose genes are involved in transport and utilization of the β-glucoside sugars arbutin, salicin, and cellibiose. This operon is activated only when the repressor is inactivated through the interruption of the gene by an insertion sequence [1] AscG also regulates prpBC for propionate catabolism [2] AscG is a GalR-type transcription factor and has a helix-turn-helix motif [1, 2] AscG recognizes and binds the consensus palindromic sequence TGAAACCGGTTTCA [2] The ascG gene is transcribed divergently from the operon it regulates [1] ascG is paralogous to galR [2] A high level of AscG is always present in wild-type Escherichia coli cells [2] Read more >

Transcription factor      
TF conformation(s):
Name Conformation Type TF-Effector Interaction Type Apo/Holo Conformation Evidence (Confirmed, Strong, Weak) References
AscG Functional   [APPHINH], [GEA], [HIFS] [1], [2]
Evolutionary Family: GalR/LacI
Sensing class: External sensing using transported metabolites
Connectivity class: Local Regulator
Gene name: ascG
  Genome position: 2838254-2839264
  Length: 1011 bp / 336 aa
Operon name: ascG
TU(s) encoding the TF:
Transcription unit        Promoter

Regulated gene(s) ascB, ascF, htpG, prpR, ybiT
Multifun term(s) of regulated gene(s) MultiFun Term (List of genes associated to the multifun term)
carbon compounds (2)
Phosphotransferase Systems (PEP-dependent PTS) (1)
membrane (1)
chaperoning, repair (refolding) (1)
fatty acids (1)
Read more >
Regulated operon(s) ascFB, htpG, prpR, ybiT
First gene in the operon(s) ascF, htpG, prpR, ybiT
Simple and complex regulons AscG
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
  AscG repressor ascFp Sigma70 -72.5 -167.5 ascF, ascB
2839350 2839364 [AIBSCS], [BPP], [GEA] [1], [2]
  AscG repressor ascFp Sigma70 4.5 -91.5 ascF, ascB
2839426 2839440 [AIBSCS], [BPP], [GEA] [2]
  AscG repressor htpGp1 Sigma32 89.5 44.5 htpG
495157 495171 [AIBSCS], [BPP] [2]
  AscG repressor prpRp Sigma70 -58.5 -86.5 prpR
348527 348533 [AIBSCS], [BPP], [GEA] [2]
  AscG repressor prpRp Sigma70 -46.5 -74.5 prpR
348515 348521 [AIBSCS], [BPP], [GEA] [2]
  AscG repressor prpRp Sigma70 -36.5 -64.5 prpR
348505 348511 [AIBSCS], [BPP], [GEA] [2]
  AscG repressor prpRp Sigma70 -29.5 -57.5 prpR
348498 348504 [AIBSCS], [BPP], [GEA] [2]
  AscG repressor prpRp Sigma70 -18.5 -46.5 prpR
348487 348493 [AIBSCS], [BPP], [GEA] [2]
  AscG repressor ybiTp nd -108.5 -124.5 ybiT
855832 855846 [AIBSCS], [BPP] [2]

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


 [APPHINH] Assay of protein purified to homogeneity from its native host

 [GEA] Gene expression analysis

 [HIFS] Human inference of function from sequence

 [AIBSCS] Automated inference based on similarity to consensus sequences

 [BPP] Binding of purified proteins


 [1] Hall BG., Xu L., 1992, Nucleotide sequence, function, activation, and evolution of the cryptic asc operon of Escherichia coli K12., Mol Biol Evol 9(4):688-706

 [2] Ishida Y., Kori A., Ishihama A., 2009, Participation of regulator AscG of the beta-glucoside utilization operon in regulation of the propionate catabolism operon., J Bacteriol 191(19):6136-44