RegulonDB RegulonDB 10.9:Regulon Page

MprA DNA-binding transcriptional repressor

Synonyms: MprA-carbonylcyanide m-chlorophenylhydrazone, MprA, MprA-2,4-dinitrophenol, MprA-Carbonyl cyanide p-(trifluoro-methoxy)phenylhydrazone
The "E. coli multidrug resistance regulator" [3], EmrR, negatively regulates the transcription of genes that code for multidrug resistance pumps that extrude structurally unrelated antimicrobial agents from the cell [3, 5] and possibly it also represses a gene that codes for a porin [5]. When EmrR is overexpressed (the emrR gene in multicopy), it is able to repress the marRAB operon, which encodes two transcriptional regulators [6]. EmrR, which is also known as MprA, "microcin production regulation, locus A" [], has also been shown to be a repressor of plasmid-encoded genes involved in microcin biosynthesis [].
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Transcription factor      
TF conformation(s):
Name Conformation Type TF-Effector Interaction Type Apo/Holo Conformation Evidence (Confirmed, Strong, Weak) References
MprA Functional   Apo [APPH], [BPP], [GEA] [1], [2], [3], [4]
MprA-2,4-dinitrophenol Non-Functional Allosteric Holo [BPP], [GEA] [1], [3], [4]
MprA-Carbonyl cyanide p-(trifluoro-methoxy)phenylhydrazone Non-Functional Allosteric Holo [BPP], [GEA] [1], [3], [4]
MprA-carbonylcyanide m-chlorophenylhydrazone Non-Functional Allosteric Holo [BPP], [GEA] [1], [3], [4]
Evolutionary Family: MarR
Connectivity class: Local Regulator
Gene name: mprA
  Genome position: 2810770-2811300
  Length: 531 bp / 176 aa
Operon name: mprA-emrAB
TU(s) encoding the TF:
Transcription unit        Promoter

Regulated gene(s) acrA, acrB, emrA, emrB, mprA, nmpC
Multifun term(s) of regulated gene(s) MultiFun Term (List of genes associated to the multifun term)
drug resistance/sensitivity (5)
membrane (4)
Porters (Uni-, Sym- and Antiporters) (3)
Electrochemical potential driven transporters (1)
Transcription related (1)
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Regulated operon(s) acrAB, mprA-emrAB, nmpC
First gene in the operon(s) acrA, mprA
Simple and complex regulons AcrR,EnvR,MarA,MprA,PhoP,Rob,SoxS
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
  MprA repressor acrAp Sigma70 -16.0 -95.0 acrA, acrB
485704 485724 [AIBSCS] [5]
  MprA repressor mprAp Sigma70 -10.0 -33.0 mprA, emrA, emrB
2810727 2810747 [BPP] [4]
  MprA repressor nmpCp nd -161.0 nd nmpC
577021 577041 [AIBSCS] [5]

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


 [1] Brooun A., Tomashek JJ., Lewis K., 1999, Purification and ligand binding of EmrR, a regulator of a multidrug transporter., J Bacteriol 181(16):5131-3

 [2] Griffith JM., Basting PJ., Bischof KM., Wrona EP., Kunka KS., Tancredi AC., Moore JP., Hyman MRL., Slonczewski JL., 2019, Experimental Evolution of Escherichia coli K-12 in the Presence of Proton Motive Force (PMF) Uncoupler Carbonyl Cyanide m -Chlorophenylhydrazone Selects for Mutations Affecting PMF-Driven Drug Efflux Pumps., Appl Environ Microbiol 85(5)

 [3] Lomovskaya O., Lewis K., Matin A., 1995, EmrR is a negative regulator of the Escherichia coli multidrug resistance pump EmrAB., J Bacteriol 177(9):2328-34

 [4] Xiong A., Gottman A., Park C., Baetens M., Pandza S., Matin A., 2000, The EmrR protein represses the Escherichia coli emrRAB multidrug resistance operon by directly binding to its promoter region., Antimicrob Agents Chemother 44(10):2905-7

 [5] Rodionov DA., Gelfand MS., Mironov AA., Rakhmaninova AB., 2001, Comparative approach to analysis of regulation in complete genomes: multidrug resistance systems in gamma-proteobacteria., J Mol Microbiol Biotechnol 3(2):319-24

 [6] Sulavik MC., Gambino LF., Miller PF., 1995, The MarR repressor of the multiple antibiotic resistance (mar) operon in Escherichia coli: prototypic member of a family of bacterial regulatory proteins involved in sensing phenolic compounds., Mol Med 1(4):436-46

 [7] Yang H., Wolff E., Kim M., Diep A., Miller JH., 2004, Identification of mutator genes and mutational pathways in Escherichia coli using a multicopy cloning approach., Mol Microbiol 53(1):283-95