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ComR DNA-binding transcriptional repressor

Synonyms: ComR
ComR is a member of the TetR family of transcriptional repressors and has been implicated in the the response of E. coli K-12 to copper.
In in vitro experiments, ComR binds to a 60 bp promotor region upstream of the comC gene [1] but is released in the presence of copper, silver or gold. Expression of comC is dramatically increased (approx 270 fold) in a comR negative strain upon exposure to 3mM copper. comR knockout mutants have lower cytoplasmic copper levels compared to the wild type when exposed to copper [1]. Expression of comR is not affected by copper [1].
Review: [2].

Transcription factor      
TF conformation(s):
Name Conformation Type TF-Effector Interaction Type Apo/Holo Conformation Evidence (Confirmed, Strong, Weak) References
ComR     nd nd
Evolutionary Family: TetR/AcrR
Connectivity class: Local Regulator
Gene name: comR
  Genome position: 1168200-1168832
  Length: 633 bp / 210 aa
Operon name: comR
TU(s) encoding the TF:
Transcription unit        Promoter

Regulated gene(s) bhsA
Multifun term(s) of regulated gene(s)
adaptations (1)
Regulated operon(s) bhsA
First gene in the operon(s) bhsA
Simple and complex regulons CRP,ComR
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
  ComR repressor bhsAp Sigma24 nd nd bhsA nd nd [BPP], [GEA] [1]

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


 [BPP] Binding of purified proteins

 [GEA] Gene expression analysis


 [1] Mermod M., Magnani D., Solioz M., Stoyanov JV., 2012, The copper-inducible ComR (YcfQ) repressor regulates expression of ComC (YcfR), which affects copper permeability of the outer membrane of Escherichia coli., Biometals. 25(1):33-43

 [2] Rademacher C., Masepohl B., 2012, Copper-responsive gene regulation in bacteria., Microbiology. 158(Pt 10):2451-64