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FrmR DNA-binding transcriptional dual regulator

Synonyms: FrmR-formol, FrmR
FrmR is a formaldehyde sensor [3] and a member of the CsoR/RcnR family of transcriptional repressors [4, 5]. It was first identified by Herring and Blattner (2004) as a negative regulator of the frmRAB operon; its function can be inactivated by suppression of its amber stop codon [1]. frmR expression is induced by formaldehyde, but not by S-nitrosoglutathione [1]. Expression of frmR is induced 41-fold upon exposure of cells to the biocide polyhexamethylene biguanide. Overexpression of frmR has no effect on the MIC of polyhexamethylene biguanide [6]. Based on in vivo and in vitro experiments, it was shown that FrmR senses the toxic chemical formaldehyde directly, with no metal dependence, via the formation of intersubunit methylene bridges between adjacent Pro2 and Cys35 residues [3]. The X-ray structure of the formaldehyde-treated FrmR tetramer has been identified at 2.7-Å resolution [3]. FrmR is conserved among the Proteobacteria [1]. FrmR: "formaldehyde-induced regulator" [1]. Read more >

Transcription factor      
TF conformation(s):
Name Conformation Type TF-Effector Interaction Type Apo/Holo Conformation Evidence (Confirmed, Strong, Weak) References
FrmR Functional   Apo [APPHINH], [IEP], [IHBCE] [1], [2]
FrmR-formol     Holo nd nd
Connectivity class: Local Regulator
Gene name: frmR
  Genome position: 379606-379881
  Length: 276 bp / 91 aa
Operon name: frmRAB
TU(s) encoding the TF:
Transcription unit        Promoter

Regulated gene(s)
Regulated operon(s)
First gene in the operon(s)
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

High-throughput Transcription factor binding sites (TFBSs)

  Functional conformation Function Object name Object type Distance to first Gene Sequence LeftPos RightPos Growth Condition Evidence (Confirmed, Strong, Weak) References
  FrmR repressor nd nd nd 379908 379957 nd [APIORCISFBSCS], [BPP], [GEA] [3]

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



 [1] Herring CD., Blattner FR., 2004, Global transcriptional effects of a suppressor tRNA and the inactivation of the regulator frmR., J Bacteriol 186(20):6714-20

 [2] Urano H., Yoshida M., Ogawa A., Yamamoto K., Ishihama A., Ogasawara H., 2017, Cross-regulation between two common ancestral response regulators, HprR and CusR, in Escherichia coli., Microbiology 163(2):243-252

 [3] Denby KJ., Iwig J., Bisson C., Westwood J., Rolfe MD., Sedelnikova SE., Higgins K., Maroney MJ., Baker PJ., Chivers PT., Green J., 2016, The mechanism of a formaldehyde-sensing transcriptional regulator., Sci Rep 6:38879

 [4] Giedroc DP, Arunkumar AI, 2007, Metal sensor proteins: nature's metalloregulated allosteric switches., Dalton Trans, 2007 Aug 7

 [5] Higgins KA, Giedroc D, 2014, Insights into Protein Allostery in the CsoR/RcnR Family of Transcriptional Repressors., Chem Lett, 2014 Jan 5

 [6] Allen MJ, White GF, Morby AP, 2006, The response of Escherichia coli to exposure to the biocide polyhexamethylene biguanide., Microbiology, 2006 Apr