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AtoC DNA-binding transcriptional activator

Synonyms: AtoC, AtoC-phosphorylated
AtoC, also known as antizyme protein (Az), is a protein that regulates processes at the transcriptional and posttranslational levels |CITS:[15200682]|. It inhibits posttranslationally ornithine decarboxylase (ODC) |CITS:[15200682]|, which is a key enzyme for biosynthesis of the polyamines which are essential components for cellular growth and proliferation |CITS:[3157043]|. On the other hand, in the presence of acetoacetate, AtoC regulates the transcription of the atoDAEB operon |CITS:[17616594][2883171]|, whose products are involved in catabolism of short-chain fatty acids |CITS:[4563344]|. However, transcriptome analyses have shown that this protein not only regulates this operon but also upregulates or downregulates 11 and 32 genes, respectively, that are involved in flagellar synthesis |CITS:[12366850]|. On the other hand, phenotypical analysis with an AtoS mutant showed reduced motility, sodium chloride sensitivity, and increased susceptibility to membrane-acting agents and an aminoglycoside antibiotic |CITS:[ 12897016]|. AtoSC is involved in the flagellar regulon, controlling the motility and chemotaxis responses |CITS: [22083893]|.
Through atoDAEB operon regulation, AtoC modules positively the biosynthesis and the intracellular distribution of poly-(R)-3-hydroxybutyrate (cPHB), a biopolymer with many physiological roles |CITS:[16564134]|. The products of the catabolism of short-chain fatty acids appear to be the substrates in the biosynthesis of this polymer |CITS:[16564134]|.
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Transcription factor      
TF conformation(s):
Name Conformation Type TF-Effector Interaction Type Apo/Holo Conformation Evidence (Confirmed, Strong, Weak) References
AtoC Non-Functional   Apo [AIFS], [BPP], [GEA], [IPI], [SM] [1], [2], [3], [4]
AtoC-phosphorylated Functional Covalent Holo [AIFS], [BPP], [GEA], [IPI], [SM] [1], [2], [3], [4]
Evolutionary Family: EBP
Sensing class: External-Two-component systems
Connectivity class: Local Regulator
Gene name: atoC
  Genome position: 2321866-2323251
  Length: 1386 bp / 461 aa
Operon name: atoSC
TU(s) encoding the TF:
Transcription unit        Promoter

Regulated gene(s) atoA, atoB, atoD, atoE
Multifun term(s) of regulated gene(s) MultiFun Term (List of genes associated to the multifun term)
fatty acids (3)
membrane (1)
Putative uncharacterized transport protein (1)
Regulated operon(s) atoDAEB
First gene in the operon(s) atoD
Simple and complex regulons AtoC,IHF
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
  AtoC-phosphorylated activator atoDp Sigma54 -138.5 -173.5 atoD, atoA, atoE, atoB
2323264 2323283 [BPP], [GEA], [HIBSCS], [SM] [3], [5], [6], [7]
  AtoC-phosphorylated activator atoDp Sigma54 -119.5 -154.5 atoD, atoA, atoE, atoB
2323283 2323302 [BPP], [GEA], [HIBSCS], [SM] [3], [5], [6], [7]

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


 [AIFS] Automated inference of function from sequence

 [BPP] Binding of purified proteins

 [GEA] Gene expression analysis

 [IPI] Inferred from physical interaction

 [SM] Site mutation

 [HIBSCS] Human inference based on similarity to consensus sequences


 [1] Filippou PS., Kasemian LD., Panagiotidis CA., Kyriakidis DA., 2008, Functional characterization of the histidine kinase of the E. coli two-component signal transduction system AtoS-AtoC., Biochim Biophys Acta. 1780(9):1023-31

 [2] Grigoroudis AI., Panagiotidis CA., Lioliou EE., Vlassi M., Kyriakidis DA., 2007, Molecular modeling and functional analysis of the AtoS-AtoC two-component signal transduction system of Escherichia coli., Biochim Biophys Acta. 1770(8):1248-58

 [3] Lioliou EE., Mimitou EP., Grigoroudis AI., Panagiotidis CH., Panagiotidis CA., Kyriakidis DA., 2005, Phosphorylation activity of the response regulator of the two-component signal transduction system AtoS-AtoC in E. coli., Biochim Biophys Acta. 1725(3):257-68

 [4] Papadopoulos G, Grigoroudis AI, Kyriakidis DA., 2010, Dimerization of the AtoC response regulator and modelling of its binding to DNA., J Mol Graph Model.

 [5] Jenkins LS., Nunn WD., 1987, Regulation of the ato operon by the atoC gene in Escherichia coli., J Bacteriol. 169(5):2096-102

 [6] Jenkins LS., Nunn WD., 1987, Genetic and molecular characterization of the genes involved in short-chain fatty acid degradation in Escherichia coli: the ato system., J Bacteriol. 169(1):42-52

 [7] Matta MK., Lioliou EE., Panagiotidis CH., Kyriakidis DA., Panagiotidis CA., 2007, Interactions of the AtoC/antizyme with regulatory elements of the Escherichia coli atoDAEB operon., J Bacteriol. 189(17):6324-32