Action at a distance for glp repressor control of glpTQ transcription in Escherichia coli K‐12

Yang, Bing; Gerhardt, Susan G.; Larson, Timothy J.

doi:10.1046/j.1365-2958.1997.3651733.x

Cited by 24 publications

(20 citation statements)

References 29 publications

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“…6B). The glpT transcriptional start site has been proposed to be an A residue 76 bases downstream of the translational start site; the site 1 element is located 36 bases upstream of the transcriptional start site (36). We confirmed that the proposed transcriptional start site is correct by 5= RACE analysis, as described in Materials and Methods (Fig.…”

Section: Torr-overexpressing Cells Have Limited Glycerol-3-phosphate supporting

confidence: 69%

Identification of a Second Two-Component Signal Transduction System That Controls Fosfomycin Tolerance and Glycerol-3-Phosphate Uptake

et al. 2015

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Particular interest in fosfomycin has resurfaced because it is a highly beneficial antibiotic for the treatment of refractory infectious diseases caused by pathogens that are resistant to other commonly used antibiotics. The biological cost to cells of resistance to fosfomycin because of chromosomal mutation is high. We previously found that a bacterial two-component system, CpxAR, induces fosfomycin tolerance in enterohemorrhagic Escherichia coli (EHEC) O157:H7. This mechanism does not rely on irreversible genetic modification and allows EHEC to relieve the fitness burden that results from fosfomycin resistance in the absence of fosfomycin. Here we show that another two-component system, TorSRT, which was originally characterized as a regulatory system for anaerobic respiration utilizing trimethylamine-N-oxide (TMAO), also induces fosfomycin tolerance. Activation of the Tor regulatory pathway by overexpression of torR, which encodes the response regulator, or addition of TMAO increased fosfomycin tolerance in EHEC. We also show that phosphorylated TorR directly represses the expression of glpT, a gene that encodes a symporter of fosfomycin and glycerol-3-phosphate, and activation of the TorR protein results in the reduced uptake of fosfomycin by cells. However, cells in which the Tor pathway was activated had an impaired growth phenotype when cultured with glycerol-3-phosphate as a carbon substrate. These observations suggest that the TorSRT pathway is the second two-component system to reversibly control fosfomycin tolerance and glycerol-3-phosphate uptake in EHEC, and this may be beneficial for bacteria by alleviating the biological cost. We expect that this mechanism could be a potential target to enhance the utility of fosfomycin as chemotherapy against multidrug-resistant pathogens.A lthough fosfomycin is classified as an old antibiotic, it was recently revived as an antibiotic that could be effective against multidrug-resistant (MDR) pathogens, such as extended-spectrum-␤-lactamase (ESBL) producers (1). This antibiotic has no structural relationship to other commonly used antibiotics; therefore, it is not affected by the development of cross-resistance in MDR pathogens (2, 3). Fosfomycin is also used to decrease the risk of development of hemolytic-uremic syndrome (HUS), which is a fatal infectious disease caused by enterohemorrhagic Escherichia coli (EHEC) O157:H7 (4-6).Fosfomycin is an antagonist of phosphoenolpyruvate (PEP) and inhibits MurA activity, which transfers PEP to the 3=-hydroxyl group of UDP-N-acetylglucosamine in the initial step of bacterial cell wall biosynthesis (7). GlpT, which is a glycerol-3-phosphate transporter, and UhpT, which is a glucose-6-phosphate transporter, are involved in the uptake of fosfomycin (8-11). Mutations in the genes encoding these proteins that result in impaired fosfomycin binding or uptake confer resistance to fosfomycin. In some E. coli studies, mutations in genes encoding the positive regulators of uhpT expression, UhpA and CyaA, confer resistance because the...

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Section: Torr-overexpressing Cells Have Limited Glycerol-3-phosphate supporting

confidence: 69%

Identification of a Second Two-Component Signal Transduction System That Controls Fosfomycin Tolerance and Glycerol-3-Phosphate Uptake

et al. 2015

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“…The genes comprising this regulon belong to five operons. Transcription of all but the glpEGR operon is negatively regulated by the glp repressor GlpR, a member of the DeoR family of transcriptional regulators (34,65,(69)(70)(71)(72). Operon glpACB, encoding the subunits of the anaerobic glycerol-P dehydrogenase, is located near min 51 of the E. coli genome (38).…”

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Characterization of a 12-Kilodalton Rhodanese Encoded by glpE of Escherichia coli and Its Interaction with Thioredoxin

et al. 2000

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Rhodaneses catalyze the transfer of the sulfane sulfur from thiosulfate or thiosulfonates to thiophilic acceptors such as cyanide and dithiols. In this work, we define for the first time the gene, and hence the amino acid sequence, of a 12-kDa rhodanese from Escherichia coli. Well-characterized rhodaneses are comprised of two structurally similar ca. 15-kDa domains. Hence, it is thought that duplication of an ancestral rhodanese gene gave rise to the genes that encode the two-domain rhodaneses. The glpE gene, a member of the sn-glycerol 3-phosphate (glp) regulon of E. coli, encodes the 12-kDa rhodanese. As for other characterized rhodaneses, kinetic analysis revealed that catalysis by purified GlpE occurs by way of an enzyme-sulfur intermediate utilizing a double-displacement mechanism requiring an active-site cysteine. The K m s for SSO 3 2؊ and CN ؊ were 78 and 17 mM, respectively. The apparent molecular mass of GlpE under nondenaturing conditions was 22.5 kDa, indicating that GlpE functions as a dimer. GlpE exhibited a k cat of 230 s ؊1 . Thioredoxin 1 from E. coli, a small multifunctional dithiol protein, served as a sulfur acceptor substrate for GlpE with an apparent K m of 34 M when thiosulfate was near its K m , suggesting that thioredoxin 1 or related dithiol proteins could be physiological substrates for sulfurtransferases. The overall degree of amino acid sequence identity between GlpE and the active-site domain of mammalian rhodaneses is limited (ϳ17%). This work is significant because it begins to reveal the variation in amino acid sequences present in the sulfurtransferases. GlpE is the first among the 41 proteins in COG0607 (rhodanese-related sulfurtransferases) of the database Clusters of Orthologous Groups of proteins (http://www.ncbi.nlm.nih.gov/COG/) for which sulfurtransferase activity has been confirmed.Genes of known function belonging to the glp regulon of Escherichia coli encode proteins that are responsible for the metabolism of sn-glycerol 3-phosphate (glycerol-P) and its precursors, glycerol and glycerophosphodiesters (38). The genes comprising this regulon belong to five operons. Transcription of all but the glpEGR operon is negatively regulated by the glp repressor GlpR, a member of the DeoR family of transcriptional regulators (34,65,(69)(70)(71)(72). Operon glpACB, encoding the subunits of the anaerobic glycerol-P dehydrogenase, is located near min 51 of the E. coli genome (38). Divergently transcribed from glpACB is glpTQ. The genes glpT and glpQ encode glycerol-P permease and periplasmic glycerophosphodiesterase, respectively (38). The glpFKX operon, at min 89, encodes glycerol diffusion facilitator, glycerol kinase, and a fructose 1,6-bisphophatase (38; J. L. Donahue, J. L. Bownas, W. G. Niehaus, Jr., and T. J. Larson, unpublished data). The genes glpE and glpG, together with the gene encoding the transcriptional repressor, glpR, form a complex operon at min 77 that is divergently transcribed from glpD (71). The gene glpD encodes the aerobic glycerol-P dehydrogenase (38).Prior to...

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“…2). The binding of IHF to this site may bend the DNA to facilitate the formation of a complex structure that is involved in the inhibition of GlpT expression, mediated by the GlpR repressor in E. coli (28 In the glpTQ intergenic region, both Hib strains contained practically identical 1,428-bp sequences, except that HK695 contained one more tetrameric repeat (TTTA) in addition to the five repeats present in Eagan. The repeats were localized in a putative open reading frame (ORF) of 414 bp in HK695, designated ORF1 for these Hib strains (Fig.…”

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confidence: 99%

“…In E. coli and Bacillus subtilis (19), glpQ is transcribed together with glpT, which is located upstream of glpQ and encodes a G3P permease that acts as a G3P-inorganic phosphate antiporter (5). The E. coli glpTQ operon is induced by G3P and repressed by the catabolic repressor glucose as well as a glp-specific repressor protein, GlpR (28). Available restriction fragment length polymorphism (RFLP) data and DNA sequences of the glpTQ region of H. influenzae suggest that its organization differs between strains (7,13,24,25).…”

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confidence: 99%

Differencesin Genetic and Transcriptional Organization of theglpTQOperons betweenHaemophilus influenzaeType b andNontypeableStrains

Song

Janson

2003

J Bacteriol

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The glpTQ operon of Haemophilus influenzae type b (Hib) and nontypeable H. influenzae (NTHi) strains is highly conserved, except for a 1.4-kb glpTQ intergenic region that was found in most Hib strains. The presence of this intergenic region results in divergent glpTQ transcriptional profiles for Hib and NTHi where Hib strains appear to have evolved an alternative promoter for glpQ expression. Based on the intergenic region's low G؉C content, we speculate that this DNA fragment was acquired by lateral transfer.Haemophilus influenzae is a common pathogen, especially among children, but the clinical manifestations are largely type specific. The encapsulated H. influenzae serotype b (Hib) usually causes invasive infections, such as meningitis and septicemia (2), whereas the much more common nonencapsulated, or nontypeable, H. influenzae (NTHi) is a major cause of otitis media, sinusitis, and pneumonia (8). General vaccination against Hib has reduced the incidence of Hib infection to a near minimum (10), while attempts to construct a vaccine against the costly NTHi infections have as yet been unsuccessful due to a high genetic heterogeneity among NTHi strains (20). An extensively studied virulence factor and potential vaccine candidate in H. influenzae is protein D, a 42-kDa conserved lipoprotein expressed on the bacterial surface (1,13,21,24). An isogenic protein D-negative mutant has been shown to be less effective than its wild-type parental strain in its ability to (i) cause experimental otitis media in rats (14), (ii) cause damage to ciliated human respiratory epithelium (15), and (iii) promote internalization into human monocytic cells (17). The mechanism behind the virulence properties of protein D is unknown but may involve choline decoration of H. influenzae lipooligosaccharides (LOS), since protein D expression allows H. influenzae to obtain choline from cocultured host cells and subsequently incorporate this molecule into its LOS (6).The ability of protein D to promote the incorporation of choline into LOS comes from its glycerophosphodiester phosphodiesterase activity, catalyzing the hydrolysis of glycerophosphodiesters into glycerol-3-phosphate (G3P) and an alcohol (14, 18). The gene encoding protein D (hpd) is homologous to glpQ of Escherichia coli (16) and other bacteria. The glpQ gene belongs to the glp regulon that is involved in the utilization of glycerol and of G3P and its precursors as energy sources and to supply precursors for phospholipid biosynthesis. In E. coli and Bacillus subtilis (19), glpQ is transcribed together with glpT, which is located upstream of glpQ and encodes a G3P permease that acts as a G3P-inorganic phosphate antiporter (5). The E. coli glpTQ operon is induced by G3P and repressed by the catabolic repressor glucose as well as a glp-specific repressor protein, GlpR (28). Available restriction fragment length polymorphism (RFLP) data and DNA sequences of the glpTQ region of H. influenzae suggest that its organization differs between strains (7,13,24,25). RFLP analysis based on...

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Action at a distance for glp repressor control of glpTQ transcription in Escherichia coli K‐12

Cited by 24 publications

References 29 publications

Identification of a Second Two-Component Signal Transduction System That Controls Fosfomycin Tolerance and Glycerol-3-Phosphate Uptake

Identification of a Second Two-Component Signal Transduction System That Controls Fosfomycin Tolerance and Glycerol-3-Phosphate Uptake

Characterization of a 12-Kilodalton Rhodanese Encoded by glpE of Escherichia coli and Its Interaction with Thioredoxin

Differencesin Genetic and Transcriptional Organization of theglpTQOperons betweenHaemophilus influenzaeType b andNontypeableStrains

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