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TdcR DNA-binding transcriptional activator

Synonyms: TdcR
During anaerobiosis, TdcR participates in controlling several genes involved in transport and metabolism of threonine and serine [1, 2, 3]
TdcR has a helix-turn-helix motif that shows 25% and 35% identity to the same motifs of the transcriptional regulators NtrC and Fis, respectively [2]
It appears that due to the fact that the tdcR gene shows poor codon usage and a poor Shine-Dalgarno sequence, it is weakly expressed [2] tdcR is transcribed alone and is located divergently in the genome from the operon (tdcABCD), whose transcription is activated by TdcR. The first gene of the operon codes for TdcA, a transcriptional regulator that probably interacts with TdcR to activate the transcription of the operon [1] and these two proteins appear to function together with CRP and IHF, proteins that bend the DNA, for this activation [3]
tdc: threonine dehydratase [4] Read more >

Transcription factor      
TF conformation(s):
Name Conformation Type TF-Effector Interaction Type Apo/Holo Conformation Evidence (Confirmed, Strong, Weak) References
TdcR     nd nd
Evolutionary Family: TdcR
Sensing class: Sensing external and internal signals
Connectivity class: Local Regulator
Gene name: tdcR
  Genome position: 3267380-3267598
  Length: 219 bp / 72 aa
Operon name: tdcR
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 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
  TdcR activator tdcAp nd -195.0 -222.5 tdcA, tdcB, tdcC, tdcD, tdcE, tdcF, tdcG
3267282 3267293 [BCE], [SM] [1]

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


 [BCE] Binding of cellular extracts

 [SM] Site mutation


 [1] 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

 [2] 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

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

 [4] Goss TJ., Datta P., 1984, Escherichia coli K-12 mutation that inactivates biodegradative threonine dehydratase by transposon Tn5 insertion., J Bacteriol. 158(3):826-31