RegulonDB RegulonDB 10.8:Regulon Page

TdcA DNA-binding transcriptional activator

Synonyms: TdcA
During anaerobiosis, TdcA participates in controlling genes (tdc operon) involved in transport and metabolism of threonine and serine [1, 3, 6] TdcA belongs to the LysR family of transcriptional regulators, and like the other members of this family, it has a helix-turn-helix motif in the N-terminal domain for DNA binding [1] Although interaction between TdcA and the regulatory region of the tdc operon has not been demonstrated, it has been suggested that TdcA recognizes and binds to an inverted repeat located upstream of the operon [3] tdcA is the first gene in the tdcABCDEFG operon, which is autoactivated by TdcA. This operon is divergently transcribed with the tdcR gene, whose product also activates the transcription of the operon [7] TdcA probably interacts with TdcR to activate transcription [3] and they appear to function together with CRP and IHF, proteins that bend the DNA, for this activation [6] A mutation in the tdcA gene of enterohemorrhagic Escherichia coli O157:H7 causes the expression of OmpA protein which is involved, among several other processes, in cellular adherence [] tdc: "threonine dehydratase" [] Read more >

Transcription factor      
TF conformation(s):
Name Conformation Type TF-Effector Interaction Type Apo/Holo Conformation Evidence (Confirmed, Strong, Weak) References
TdcA Functional   [IE] [1], [2], [3], [4], [5]
Evolutionary Family: LysR
Sensing class: Sensing external and internal signals
Connectivity class: Local Regulator
Gene name: tdcA
  Genome position: 3266127-3267065
  Length: 939 bp / 312 aa
Operon name: tdcABCDEFG
TU(s) encoding the TF:
Transcription unit        Promoter

Regulated gene(s) tdcA, tdcB, tdcC, tdcD, tdcE, tdcF, tdcG
Multifun term(s) of regulated gene(s) MultiFun Term (List of genes associated to the multifun term)
amino acids (4)
threonine catabolism (3)
Transcription related (1)
activator (1)
operon (1)
Read more >
Regulated operon(s) tdcABCDEFG
First gene in the operon(s) tdcA
Simple and complex regulons CRP,FNR,IHF,TdcA,TdcR
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
  TdcA activator tdcAp nd -177.0 -205.0 tdcA, tdcB, tdcC, tdcD, tdcE, tdcF, tdcG
3267263 3267277 [BCE], [CV(GEA)], [CV(GEA)], [CV(GEA/SM)], [CV(SM)], [GEA], [SM] [3]

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


 [IE] Inferred from experiment

 [BCE] Binding of cellular extracts

 [CV(GEA)] cross validation(GEA)

 [CV(GEA/SM)] cross validation(GEA/SM)

 [CV(SM)] cross validation(SM)

 [GEA] Gene expression analysis

 [SM] Site mutation


 [1] Ganduri YL., Sadda SR., Datta MW., Jambukeswaran RK., Datta P., 1993, TdcA, a transcriptional activator of the tdcABC operon of Escherichia coli, is a member of the LysR family of proteins., Mol Gen Genet 240(3):395-402

 [2] Goss TJ., Datta P., 1985, Molecular cloning and expression of the biodegradative threonine dehydratase gene (tdc) of Escherichia coli K12., Mol Gen Genet 201(2):308-14

 [3] Hagewood BT., Ganduri YL., Datta P., 1994, Functional analysis of the tdcABC promoter of Escherichia coli: roles of TdcA and TdcR., J Bacteriol 176(20):6214-20

 [4] Rodrigues GA., Park M., 1993, Dimerization mediated through a leucine zipper activates the oncogenic potential of the met receptor tyrosine kinase., Mol Cell Biol 13(11):6711-22

 [5] Schweizer HP., Datta P., 1989, The complete nucleotide sequence of the tdc region of Escherichia coli., Nucleic Acids Res 17(10):3994

 [6] Sawers G., 2001, A novel mechanism controls anaerobic and catabolite regulation of the Escherichia coli tdc operon., Mol Microbiol 39(5):1285-98

 [7] Schweizer HP., Datta P., 1989, Identification and DNA sequence of tdcR, a positive regulatory gene of the tdc operon of Escherichia coli., Mol Gen Genet 218(3):516-22