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ArsR DNA-binding transcriptional repressor

Synonyms: ArsR-arsenite, ArsR, ArsR-antimonite ion
ArsR negatively controls the expression of the genes involved in arsenical and antimonite metals resistance whose expression is induced in the presence of these metals [2, 4, 5, 6] This protein is autoregulated; arsR is the first gene in the arsRBC operon that it regulates [6] ArsR belongs to the ArsR/SmtB family of transcriptional regulators that respond to a variety of metals [1] ArsR has a helix-turn-helix motif for DNA binding, a metal-binding site [3] and a dimerization domain [7] The inducer-binding sites for the members of this family appear to have arisen by convergent evolution [] In ArsR the inducer-binding site contains three cysteine residues that bind arsenite and antimonite specifically and with high affinity [3] Dimerization of ArsR is required for DNA binding and its ability to act as a transcriptional repressor [7] The dimer recognizes and binds to a 12-2-12 inverted repeat [1, 4] but the binding of arsenic or antimonite to ArsR causes a conformational change in it, leading to dissociation from DNA and hence derepression [] The chromosomal ArsR shows 75% identity to ArsR of Escherichia coli plasmid R773 and 26% identity to staphylococcal plasmid pI258 and pSX267 ArsR proteins [5] ArsR when overexpressed has the capacity to remove arsenic species from contaminated water [] ArsR: homologous to "arsenate inducibility regulator" [6] Review: [1] Read more >

Transcription factor      
TF conformation(s):
Name Conformation Type TF-Effector Interaction Type Apo/Holo Conformation Evidence (Confirmed, Strong, Weak) References
ArsR Functional   Apo [APPHINH], [HIFS], [IEP] [1], [2], [3], [4]
ArsR-antimonite ion Non-Functional Allosteric Holo nd nd
ArsR-arsenite Non-Functional Allosteric Holo nd nd
Evolutionary Family: ArsR
Sensing class: External sensing using transported metabolites
Connectivity class: Local Regulator
Gene name: arsR
  Genome position: 3648528-3648881
  Length: 354 bp / 117 aa
Operon name: arsRBC
TU(s) encoding the TF:
Transcription unit        Promoter

Regulated gene(s) arsB, arsC, arsR
Multifun term(s) of regulated gene(s) MultiFun Term (List of genes associated to the multifun term)
detoxification (2)
The Arsenite-Antimonite (Ars) Efflux Family (1)
membrane (1)
Transcription related (1)
repressor (1)
Read more >
Regulated operon(s) arsRBC
First gene in the operon(s) arsR
Simple and complex regulons ArsR
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
  ArsR repressor arsRp Sigma70 -41.5 -57.5 arsR, arsB, arsC
3648459 3648482 [AIBSCS], [BPP], [GEA] [1], [2], [4]

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


 [APPHINH] Assay of protein purified to homogeneity from its native host

 [HIFS] Human inference of function from sequence

 [IEP] Inferred from expression pattern

 [AIBSCS] Automated inference based on similarity to consensus sequences

 [BPP] Binding of purified proteins

 [GEA] Gene expression analysis


 [1] Busenlehner LS., Pennella MA., Giedroc DP., 2003, The SmtB/ArsR family of metalloregulatory transcriptional repressors: Structural insights into prokaryotic metal resistance., FEMS Microbiol Rev 27(2-3):131-43

 [2] Cai J., DuBow MS., 1996, Expression of the Escherichia coli chromosomal ars operon., Can J Microbiol 42(7):662-71

 [3] Shi W., Wu J., Rosen BP., 1994, Identification of a putative metal binding site in a new family of metalloregulatory proteins., J Biol Chem 269(31):19826-9

 [4] Xu C., Shi W., Rosen BP., 1996, The chromosomal arsR gene of Escherichia coli encodes a trans-acting metalloregulatory protein., J Biol Chem 271(5):2427-32

 [5] Carlin A., Shi W., Dey S., Rosen BP., 1995, The ars operon of Escherichia coli confers arsenical and antimonial resistance., J Bacteriol 177(4):981-6

 [6] Diorio C., Cai J., Marmor J., Shinder R., DuBow MS., 1995, An Escherichia coli chromosomal ars operon homolog is functional in arsenic detoxification and is conserved in gram-negative bacteria., J Bacteriol 177(8):2050-6

 [7] Xu C., Rosen BP., 1997, Dimerization is essential for DNA binding and repression by the ArsR metalloregulatory protein of Escherichia coli., J Biol Chem 272(25):15734-8