RegulonDB RegulonDB 9.3:Regulon Page

HypT DNA-binding transcriptional dual regulator

Synonyms: HypT-Met-oxidized
HypT belongs to the LysR-type transcriptional regulator family, which protects cells from HOCl damage |CITS: [22223481][24116067]|. It regulates several genes upon hypochlorite stress, which increases cellular viability by reducing the intracellular iron levels |CITS: [22223481]|. This assumes a primary role for HypT in downregulating iron acquisition genes in order to prevent further synthesis of iron uptake proteins |CITS: [22223481]|.
HypT is specifically activated by HOCl by methionine oxidation, protecting the cells from the detrimental effects of HOCl) |CITS: [22223481]|. HypT belongs to the large family of LTTRs and is conserved in α-, β-, and γ-proteobacteria and eukaryotes (Xenopus tropicalis), which suggests conservation of the HOCl response in evolution and its maintenance throughout the kingdoms |CITS: [22223481]|.
Based on microarray analysis, HypT upregulates genes involved in cysteine and methionine biosynthesis and sulfur metabolism upon hypochlorite stress. On the other hand, genes involved in iron acquisition and homeostasis upon hypochlorite stress are downregulated by YjiE |CITS: [22223481]|.
HypT has five cysteine residues which contribute to control the DNA-binding activity of HypT in vitro |CITS: [24116067]|. Cys150 is required for stability, Cys4 is important for oligomerization of HypT to dodecamers, and Cys4 oxidation may be a checkpoint in the activation process of HypT |CITS: [24116067]|.
The building block of HypT is likely a dimer; similar to other LTTRs, it forms unusually large oligomers, as dodecameric ring-like structures, in vitro that undergo large DNA-induced conformational changes to form dimers and tetramers |CITS: [22223481]|.
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Transcription factor      
TF conformation(s):
Name Conformation Type TF-Effector Interaction Type Apo/Holo Conformation Evidence (Confirmed, Strong, Weak) References
HypT-Met-oxidized     nd nd
Evolutionary Family: LysR
Connectivity class: Local Regulator
Gene name: hypT
  Genome position: 4557378-4558289
  Length: 912 bp / 303 aa
Operon name: hypT
TU(s) encoding the TF:
Transcription unit        Promoter

Regulated gene(s) cydA, cydB, cysH, fecA, fecB, fecC, fecD, fecE, metB, metI, metL, metN, metQ
Multifun term(s) of regulated gene(s) MultiFun Term (List of genes associated to the multifun term)
membrane (5)
Fe aquisition (4)
ABC superfamily, membrane component (3)
electron acceptors (2)
ABC superfamily, periplasmic binding component (2)
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Regulated operon(s) cydAB, cysJIH, fecABCDE, metBL, metNIQ
First gene in the operon(s) cydA, cysH, fecA, metB, metN
Simple and complex regulons ArcA,FNR,H-NS,HypT
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
  HypT-Met-oxidized activator cydAp1 Sigma70 nd nd cydA, cydB nd nd [BPP], [GEA] [1]
  HypT-Met-oxidized activator cysHp nd nd nd cysH nd nd [GEA] [1], [2]
  HypT-Met-oxidized repressor fecAp Sigma19 nd nd fecA, fecB, fecC, fecD, fecE nd nd [GEA] [1], [2]
  HypT-Met-oxidized activator metBp Sigma70 nd nd metB, metL nd nd [GEA] [1], [2]
  HypT-Met-oxidized activator metNp Sigma70 nd nd metN, metI, metQ nd nd [BPP], [GEA] [1], [2]

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] Gebendorfer KM., Drazic A., Le Y., Gundlach J., Bepperling A., Kastenmuller A., Ganzinger KA., Braun N., Franzmann TM., Winter J., 2012, Identification of a Hypochlorite-specific Transcription Factor from Escherichia coli., J Biol Chem. 287(9):6892-903

 [2] Drazic A., Miura H., Peschek J., Le Y., Bach NC., Kriehuber T., Winter J., 2013, Methionine oxidation activates a transcription factor in response to oxidative stress., Proc Natl Acad Sci U S A. 110(23):9493-8