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

Sulavik, Mark C.; Gambino, Laura; Miller, Paul

doi:10.1007/bf03401581

Cited by 163 publications

(149 citation statements)

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“…5) analyses also implicated the transcription factor MarR (Ssol_1340) as a member of the mercury regulon. As a regulator of oxidative stress (Alekshun & Levy, 1999;Ariza et al, 1994;Cohen et al, 1993;Ellison & Miller, 2006;Li et al, 2011;Sulavik et al, 1995), its regulated expression may arise from the impact of mercury on free thiols that are titrated by metal sequestration leading to oxidative stress. The MarR transcription factor family shares a common origin in bacteria and archaea as revealed by a conserved N-terminal 40 aa sequence motif (Pérez-Rueda & Collado-Vides, 2001).…”

Section: Discussionmentioning

confidence: 99%

“…Structurally homologous MarR proteins are winged helix-turn-helix dimers that bind palindromic promoter sequences to regulate transcription through exogenous ligand binding (Martin & Rosner, 1995). The regulated genes are functionally linked to antibiotic resistance, oxidative stress response, heat shock resistance, virulence, catabolism of aromatic compounds, and export of disinfectants and organic solvents (Alekshun & Levy, 1999;Ariza et al, 1994;Cohen et al, 1993;Ellison & Miller, 2006;Li et al, 2011;Sulavik et al, 1995). Three other MarR proteins of Sulfolobus have now been characterized by crystallography, and their ability to bind DNA is modulated by ligands with various affinities (Kumarevel et al, 2008).…”

Section: Discussionmentioning

confidence: 99%

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Identification of an archaeal mercury regulon by chromatin immunoprecipitation

et al. 2015

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Mercury is a heavy metal and toxic to all forms of life. Metal exposure can invoke a response to improve survival. In archaea, several components of a mercury response system have been identified, but it is not known whether metal transport is a member of this system. To identify such missing components, a peptide-tagged MerR transcription factor was used to localize enriched chromosome regions by chromosome immunoprecipitation combined with DNA sequence analysis. Such regions could serve as secondary regulatory binding sites to control the expression of additional genes associated with mercury detoxification. Among the 31 highly enriched loci, a subset of five was pursued as potential candidates based on their current annotations. Quantitative reverse transcription-PCR analysis of these regions with and without mercury treatment in WT and mutant strains lacking merR indicated significant regulatory responses under these conditions. Of these, a Family 5 extracellular solute-binding protein and the MarR transcription factor shown previously to control responses to oxidation were most strongly affected. Inactivation of the solute-binding protein by gene disruption increased the resistance of mutant cells to mercury challenge. Inductively coupled plasma-MS analysis of the mutant cell line following metal challenge indicated there was less intracellular mercury compared with the isogenic WT strain. Together, these regulated genes comprise new members of the archaeal MerR regulon and reveal a cascade of transcriptional control not previously demonstrated in this model organism.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Identification of an archaeal mercury regulon by chromatin immunoprecipitation

et al. 2015

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“…These regulators bind DNA through a helix-turn-helix (HTH) motif (Cohen et al, 1993;Sulavik et al, 1995). Members of the MarR family control an assortment of biological functions including the expression of resistance to multiple antibiotics, detergents and oxidative stress agents, organic solvents, and pathogenic factors (Alekshun and Levy, 1999;Miller and Sulavik, 1996).…”

Section: Introductionmentioning

confidence: 99%

Specific binding of the regulatory protein ExpG to promoter regions of the galactoglucan biosynthesis gene cluster of Sinorhizobium meliloti - a combined molecular biology and force spectroscopy investigation

Bartels

Baumgarth

Anselmetti

et al. 2003

Journal of Structural Biology

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Specific protein-DNA interaction is fundamental for all aspects of gene transcription. We focus on a regulatory DNA-binding protein in the Gram-negative soil bacterium Sinorhizobium meliloti 2011, which is capable of fixing molecular nitrogen in a symbiotic interaction with alfalfa plants. The ExpG protein plays a central role in regulation of the biosynthesis of the exopolysaccharide galactoglucan, which promotes the establishment of symbiosis. ExpG is a transcriptional activator of exp gene expression. We investigated the molecular mechanism of binding of ExpG to three associated target sequences in the exp gene cluster with standard biochemical methods and single molecule force spectroscopy based on the atomic force microscope (AFM). Binding of ExpG to expA1, expG-expD1, and expE1 promoter fragments in a sequence specific manner was demonstrated, and a 28 bp conserved region was found. AFM force spectroscopy experiments confirmed the specific binding of ExpG to the promoter regions, with unbinding forces ranging from 50 to 165 pN in a logarithmic dependence from the loading rates of 70-79 000 pN/s. Two different regimes of loading rate-dependent behaviour were identified. Thermal off-rates in the range of k off ¼ ð1:2 AE 1:0Þ Â 10 À3 s À1 were derived from the lower loading rate regime for all promoter regions. In the upper loading rate regime, however, these fragments exhibited distinct differences which are attributed to the molecular binding mechanism.

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“…The natural signal for the marRAB operon has not been identified as it remains unknown whether plant-derived napthoquinones are natural inducers (10). It has been shown that the operon is activated by compounds such as salicylate, chloramphenicol, tetracycline, acetaminophen, sodium benzoate, 2,4-dinitrophenol, cinnamate, carbonyl cyanide m-chloro-phenylhydrazone, menadione, and plumbagin (11,12). In the presence of specific antibiotics (such as tetracycline and chloramphenicol; see Refs.…”

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confidence: 99%