Nucleotide sequence of the xth gene of Escherichia coli K-12

Saporito, S M; Smith-White, Brian; Cunningham, Richard P.

doi:10.1128/jb.170.10.4542-4547.1988

Cited by 75 publications

(39 citation statements)

References 48 publications

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“…A unique consensus sequence for U38 promoters was proposed (1,30,35,36,44), but its validity is now doubtful (4,8,17), since several cr38-dependent genes, including glgS (9), cyx4 (6), osmB (14), fic (42), and, as shown here, pexB, do not have such sequences. Tanaka et al (42) and Nguyen et al (30a) report that most promoters recognized by Eo8 in vitro were also recognized by Eu70 and that all contained a typical -10 a70 region.…”

Section: Discussionmentioning

confidence: 99%

Characterization of the sigma 38-dependent expression of a core Escherichia coli starvation gene, pexB

1994

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A reverse genetics approach was used to clone a pex starvation gene that codes for an 18-kDa polypeptide, designated PexB. Single-copy pexB-lacZ operon fusions were constructed to study transcriptional regulation and the promoter region of this gene. The induction by carbon starvation or osmotic stress was transcriptional and controlled by or38 but was independent of this sigma factor by the oxidative stress; presumably, it was if70 mediated under the latter stress. During nitrogen starvation, the induction was controlled at the posttranscriptional level. The perB upstream region contained 245 nucleotides within which sequences approximating the consensus for cyclic AMP receptor protein and integration host factor binding sites were discernible. Deletion of 164 bp of the upstream region, which included these consensus sequences, did not affect starvationor osmotic stress-mediated induction ofpexB but abolished its induction by oxidative stress. The same start site was used in transcription during carbon starvation, osmotic stress, or oxidative stress, suggesting that thepexB promoter can be recognized in vivo by both if38 and cr70, depending, presumably, on the presence of appropriate transcriptional factors. The -10 and -35 regions of pexB resembled those of some but not all genes known to be controlled by if38.At the onset of carbon starvation, Escherichia coli induces some 50 polypeptides, which fall in several temporal classes. This induction is associated with the development of marked general resistance (7, 11-13, 21-23, 34). We are attempting to identify and characterize the individual polypeptides that contribute to this resistance. A core set of 15 polypeptides is induced regardless of whether the cells are starved for carbon, nitrogen, or phosphorus, and since this set includes many heat, oxidative, and osmotic shock proteins (7), we have focused on these polypeptides. This core set of proteins is regulated differently from most of the other carbon starvation proteins. First, their induction is independent of cyclic AMP (cAMP), while that of the rest requires this nucleotide. On this basis, we differentiated starvation proteins into Pex (cAMP independent) and Cst (cAMP dependent) (22,39). Second, the induction of several Pex proteins requires secondary a factors. Thus, a32 is required for the induction of at least three Pex proteins, DnaK, GroEL, and HtpG, and mutants deficient in this sigma factor survive starvation poorly (11). Similarly, c38 (also referred to as as and KatF [29]) is required for the induction of at least six Pex proteins (25), and E. coli mutants deficient in o38 (QpoS) are greatly compromised in the development of starvation-mediated resistance (18,25).This report deals with an 18-kDa membrane-associated (39) Pex protein that we identified in 1986 as spot 19 on our two-dimensional (2-D) gel electrophoresis maps (7,22,39) and subsequently named PexB (15). This protein is induced early in starvation and exhibits a sustained induction during carbon starvation: at 4 h of glucose or suc...

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Section: Discussionmentioning

confidence: 99%

Characterization of the sigma 38-dependent expression of a core Escherichia coli starvation gene, pexB

1994

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“…Information about transcripts is even more sparse. Interestingly, however, the xthA promoter used in viva lacks a -35 (u 7 Dj region (Saporito et al, 1988) and the start pOints of three different glgC transcripts are preceded by regions with poor homology to the -35 and -10 (u 7 Dj consensus sequences (Romeo and Preiss, 1989). This also strongly argues for the rpaS gene product as an alternative sigma factor (us).…”

Section: Discussionmentioning

confidence: 99%

“…only for the gIg genes (Preiss, 1984), xthA (Saporito et al, 1988) and the amino-terminal region of appA (Touati and Danchin, 1987). Information about transcripts is even more sparse.…”

Section: Discussionmentioning

confidence: 99%

Identification of a central regulator of stationary‐phase gene expression in Escherichia coli

Lange

Hengge‐Aronis

1991

Molecular Microbiology

751

679

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SummaryDuring carbon-starvation-induced entry into stationary phase, Escherichia coli cells exhibit a variety of physiological and morphological changes that ensure survival during periods of prolonged starvation. Induction of 30-50 proteins of mostly unknown function has been shown under these conditions. In an attempt to identify C-starvation-regulated genes we isolated and characterized chromosomal C-starvation-induced csi::/acZ fusions using the x.p/acMu syste-;". One operon fusion (csi2::/acZ) has been studied in detail. csi2::/acZ was induced during transition from exponential to stationary phase and was negatively regulated by cAMP. It was mapped at 59 min on the E. coli chromosome and conferred a pleiotropic phenotype. As demonstrated by two-dimensional gel electrophoresis, cells carrying csi2::/acZ did not synthesize at least 16 proteins present in an isogenic csi2+ strain. Cells containing csi2::/acZ or csi2::Tn 10 did not produce glycogen, did not develop thermotolerance and H20 2 resistance, and did not induce a stationary-phase-specific acidic phosphatase (AppA) as well as another csi fusion (csi5::/acZ). Moreover, they died off much more rapidly than wild-type cells during prolonged starvation. We conclude that csi2::/acZ defines a regulatory gene of central importance for stationary phase E. coli cells. These results and the cloning of the wild-type gene corresponding to csi2 demonstrated that the csi2 locus is allelic with the previously identified regulatory genes katF and appR. The katF sequence indicated that its gene product is a novel sigma factor supposed to regulate expression of catalase HPII and exonuclease III (Mulvey and Loewen, 1989). We suggest that this novel sigma subunit of RNA polymerase defined by csi21 katF/appR is a central early regulator of a large starvation/stationary phase regulon in E. coli and propose 'rpoS' (' us,) as appropriate designations.

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“…The HAP1 protein is highly homologous to DNA repair enzymes from other mammals and Drosophila and bacterial species (7,(21)(22)(23)(24)(25). This sequence conservation extends throughout the length of the proteins with the exception of a eukaryote-specific N-terminal domain which comprises 61 residues in the human protein.…”

Section: Discussionmentioning

confidence: 99%

Identification of residues in the human DNA repair enzyme HAP1 (Ref-1) that are essential for redox regulation of Jun DNA binding.

Walker¹,

Robson²,

Black³

et al. 1993

Mol. Cell. Biol.

257

207

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The DNA binding activity of the c-jun proto-oncogene product is inhibited by oxidation of a specific cysteine residue Modulating the level of expression of specific genes is a prerequisite for the control of cellular growth and differentiation. Gene expression is controlled by sequence-specific DNA binding proteins (transcription factors) which in certain cases are targets for signals transduced from cell surface receptors. The importance of this process for growth control is emphasized by the finding that several proto-oncogenes, including c-myc, c-myb, c-fos, and c-jun, encode sequencespecific transcription factors (reviewed in reference 20). Although the activity of these factors can be modulated by phosphorylation (4, 11), recent evidence has emerged for an additional and unusual form of regulation of DNA binding activity mediated by changes in reduction-oxidation (redox) status.

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Nucleotide sequence of the xth gene of Escherichia coli K-12

Cited by 75 publications

References 48 publications

Characterization of the sigma 38-dependent expression of a core Escherichia coli starvation gene, pexB

Characterization of the sigma 38-dependent expression of a core Escherichia coli starvation gene, pexB

Identification of a central regulator of stationary‐phase gene expression in Escherichia coli

Identification of residues in the human DNA repair enzyme HAP1 (Ref-1) that are essential for redox regulation of Jun DNA binding.

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