Anaerobically induced genes of Escherichia coli

Winkelman, J W; Clark, David P.

doi:10.1128/jb.167.1.362-367.1986

Cited by 47 publications

(36 citation statements)

References 36 publications

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“…Solid media contained 1n5% (w\v) Difco BactoAgar. All anaerobic growth media were supplemented with the trace metals Fe (50 µM), Se (5 µM), Mo (5 µM) and Mn (5 µM) as described previously (Winkelman & Clark, 1986). Growth was followed turbidometrically using a KlettSummerson colorimeter equipped with a green (540 nm) filter.…”

Section: Methodsmentioning

confidence: 99%

“…LDH was assayed by following the decrease in absorbance at 340 nm as NADH was oxidized to NAD + by pyruvate, as previously described (Mat-Jan et al, 1989). β-Galactosidase was assayed as described previously (Winkelman & Clark, 1986), except that cultures were grown to mid-exponential phase (approx. 5i10) cells ml − ") before assay in a variety of media under This study both aerobic and anaerobic conditions.…”

Section: Methodsmentioning

confidence: 99%

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Regulation of the ldhA gene, encoding the fermentative lactate dehydrogenase of Escherichia coli

2001

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The fermentative lactate dehydrogenase (LDH) of Escherichia coli is induced by low pH under anaerobic conditions. Both translational and transcriptional gene fusions to ldhA, which encodes the fermentative LDH, have now been made. Both types of ldhA-lacZ fusion were induced by low pH, but only in the absence of air. However, the translational fusions were consistently expressed at a five-to tenfold higher level than the transcriptional fusions, perhaps implying some post-transcriptional effect on ldhA expression. Introduction of arcB ::Kan decreased expression of both translational and transcriptional ldhA-lacZ fusions by three-to fivefold. Disruption of mlc, which encodes a repressor of several genes of the phosphotransferase system, almost abolished expression of ldhA. Disruption of csrA caused a moderate drop in expression of both operon and protein ldhA fusions, whereas insertional inactivation of csrB or glgA had the opposite effect. These effects are probably indirect, resulting from alterations in sugar accumulation versus storage. Mutations in ptsG, cra, fnr, narL, rpoS, osmZ, appY, ack/pta, aceEF, pfl and ldhA had no effect on expression of the ldhA fusions. ldhA was not induced by the membranepermeant weak acid benzoate, implying that it does not respond to the internal pH directly. Little pH induction was seen during growth on glycerol plus fumarate, suggesting that products of sugar fermentation are necessary for acid induction. Addition of succinate, acetate or lactate had no effect on ldhA expression. In contrast, pyruvate caused a two-to fourfold increase in expression of ldhA-lacZ. This accords with the idea that increased sugar metabolism indirectly induces ldhA.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Regulation of the ldhA gene, encoding the fermentative lactate dehydrogenase of Escherichia coli

2001

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“…While the roles of many of these genes are known (for a review, see reference 23), others are not (1,13,49). Genes of the latter group were identified by several investigators who used lacZ operon fusion techniques to screen for genes that were optimally expressed under anaerobic cell growth conditions (1,13,49). In E. coli, a large number of genes were identified by Winkelman and Clark (49) that are repressed by the presence of anaerobic electron acceptors, such as dimethyl sulfoxide (DMSO) and trimethylamine-N-oxide (TMAO).…”

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Characterization of the aegA locus of Escherichia coli: control of gene expression in response to anaerobiosis and nitrate

et al. 1996

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Analysis of the DNA sequence upstream of the narQ gene, which encodes the second nitrate-responsive sensor-transmitter protein in Escherichia coli, revealed an open reading frame (ORF) whose product shows a high degree of similarity to a number of iron-sulfur proteins as well as to the ␤ subunit of glutamate synthase (gltD) of E. coli. This ORF, located at 53.0 min on the E. coli chromosome, is divergently transcribed and is separated by 206 bp from the narQ gene. Because of the small size of the intergenic region, we reasoned that the genes may be of related function and/or regulated in a similar fashion. An aegA-lacZ gene fusion was constructed and examined in vivo; aegA expression was induced 11-fold by anaerobiosis and repressed 5-fold by nitrate. This control was mediated by the fnr, narX, narQ, and narL gene products. Analysis of an aegA mutant indicated that the aegA gene product is not essential for cell respiration or fermentation or for the utilization of ammonium or the amino acids L-alanine, L-arginine, L-glutamic acid, glycine, and DL-serine as sole nitrogen sources. The ORF was designated aegA to reflect that it is an anaerobically expressed gene. The structural properties of the predicted AegA amino acid sequence and the regulation of aegA are discussed with regard to the possible function of aegA in E. coli.A number of genes in Escherichia coli are expressed optimally under anaerobic growth conditions. These include the genes involved in anaerobic respiration or fermentation. While the roles of many of these genes are known (for a review, see reference 23), others are not (1,13,49). Genes of the latter group were identified by several investigators who used lacZ operon fusion techniques to screen for genes that were optimally expressed under anaerobic cell growth conditions (1,13,49). In E. coli, a large number of genes were identified by Winkelman and Clark (49) that are repressed by the presence of anaerobic electron acceptors, such as dimethyl sulfoxide (DMSO) and trimethylamine-N-oxide (TMAO). It was proposed that these genes encode fermentation-related enzymes. Choe and Reznikoff (13) identified nine anaerobically expressed genes (designated aeg) and studied their regulation. Their roles are unknown, but one, aeg-93, is proposed to encode a respiratory (formate-linked) nitrite reductase (46). While the aeg genes are anaerobically expressed, they exhibit different patterns of control in fnr, narL, and rpoN strains (13).In this study, we report the identification of a new aeg locus, designated aegA, that is located upstream of the narQ regulatory gene (11,12,34). To further investigate the role of the aegA locus, we physically mapped and DNA sequenced the locus. A strain with a mutation in this locus was constructed and tested for changes in growth requirements. We also examined the regulation of the aegA locus by constructing an aegAlacZ reporter fusion. It was found that expression of aegA is controlled by anaerobiosis and nitrate and that this regulation is mediated by the fnr, narXL, and n...

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“…Various oxr mutants were subjected to two-dimensional polyacrylamide electrophoretic analysis of anaerobiosis-inducible proteins. Several pathways of anaerobic control were observed by means of these techniques.There have been several reports identifying genes in Salmonella typhimurium and Escherichia coli whose expressions are controlled by the presence or absence of molecular oxygen (1,10,35,37). Anaerobiosis-inducible genes with unidentified products have been referred to as ani (1) and oxd (35).…”

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confidence: 99%

“…There have been several reports identifying genes in Salmonella typhimurium and Escherichia coli whose expressions are controlled by the presence or absence of molecular oxygen (1,10,35,37). Anaerobiosis-inducible genes with unidentified products have been referred to as ani (1) and oxd (35).…”

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Novel regulatory loci controlling oxygen- and pH-regulated gene expression in Salmonella typhimurium

et al. 1988

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Three new loci were discovered, each of which participates in the regulation of anaerobic gene expression. The regulatory gene earA negatively regulates the expression of the anaerobiosis-inducible gene aniG as well as that of at least three other genes, as determined by two-dimensional polyacrylamide gel electrophoresis. The earA locus maps at 86 min. The expression of aniG was also shown to be controlled by changes in external pH under aerobic and anaerobic conditions. Maximal expression was observed under anaerobic conditions at an external pH of 6.0. Significant transcriptional activity was also observed under aerobic conditions at pH 6.0. This was in contrast to hyd, whose expression was dependent upon anaerobiosis and varied with external pH. The pH dependence disappeared under fully aerobic conditions. Mutations in earA had no effect upon hyd expression. The two other regulators identified were oxrF, which controls aniH, and oxrG, which, in concert with oxrA and oxrB, controls aniC and anil. The oxrG locus was mapped to 88 min and appears to code for a positive regulator. Various oxr mutants were subjected to two-dimensional polyacrylamide electrophoretic analysis of anaerobiosis-inducible proteins. Several pathways of anaerobic control were observed by means of these techniques.There have been several reports identifying genes in Salmonella typhimurium and Escherichia coli whose expressions are controlled by the presence or absence of molecular oxygen (1,10,35,37). Anaerobiosis-inducible genes with unidentified products have been referred to as ani (1) and oxd (35). These genes were discovered by generating random lacZ operon fusions in the chromosome with Mu d(Ap lac) phage. Identified anaerobiosis-inducible genes include those involved with nitrate (nar; 4, 14, 34) and fumarate (frd; 21, 22) reductases, hydrogen sulfide production (phs; 1, 11), cobalamine biosynthesis (cob; 13), hydrogenase (hyd; 1, 20, 39), some peptidases and peptide permeases (tppB, pepT; 15, 18, 19, 35), anaerobic L-a-glycerophosphate dehydrogenase (glpAB; 23), NAD biosynthesis (nadAB; 17), degradative threonine dehydratase (28), formate hydrogen lyase (fhl; 31), a tertiary amine oxidase (torA; 24, 30), menaquinone synthesis (men; 24), and dimethyl sulfoxide reductase (23). Several genes have been implicated in S. typhimurium as participating in anaerobic transcriptional control. These include oxrA, a positive regulator equivalent to fnr in E. coli (7,25,35); oxrB, another positive regulator (35); oxrC (pgi), not a transcriptional regulator but involved with the generation of an inducing signal (19); and tppR, a positive regulator of tppB (18).The most characterized anaerobic regulatory locus is fnr of E. coli. Mutations in fnr prevent the anaerobic induction of several respiratory enzymes, such as the nitrate and fumarate reductases, hydrogenase 2, dimethyl sulfoxide reductase, and glycerol-3-phosphate dehydrogenase (3,7,23,25,34 (1,11,18,19,30,35). The molecular mechanism(s) controlling the expressions of these genes remains obs...

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Anaerobically induced genes of Escherichia coli

Cited by 47 publications

References 36 publications

Regulation of the ldhA gene, encoding the fermentative lactate dehydrogenase of Escherichia coli

Regulation of the ldhA gene, encoding the fermentative lactate dehydrogenase of Escherichia coli

Characterization of the aegA locus of Escherichia coli: control of gene expression in response to anaerobiosis and nitrate

Novel regulatory loci controlling oxygen- and pH-regulated gene expression in Salmonella typhimurium

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