A nested set of C‐terminal deletions of the α subunit of <i>Escherichia coli</i> RNA polymerase define regions concerned with assembly, proteolysis, stabilization and transcriptional activation <i>in vivo</i>

Zou, Chao; Thomas, Mark S.; Keen, J.M.; Glass, Robert E.

doi:10.1046/j.1365-2443.1997.960296.x

Cited by 8 publications

(4 citation statements)

References 45 publications

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“…We used the E. coli background and measured promoter activity of a P fur–lacZ transcriptional fusion in a strain overexpressing either a wild type α‐subunit (RpoA) or a C‐terminally truncated α ‐subunit (RpoA Δ256 ) of E. coli . The pACYC‐Cl2 plasmid carrying the P fur–lacZ fusion was co‐transformed into the E. coli with either the plaw2 (RpoA; Zou et al ., 1992) or the plaw2(Δ256) (RpoA Δ256 ; Zou et al ., 1997) plasmids. These strains were grown to logarithmic phase and the promoter activity of P fur in each was measured by Miller assay (Miller, 1972).…”

Section: Resultsmentioning

confidence: 99%

An anti‐repression Fur operator upstream of the promoter is required for iron‐mediated transcriptional autoregulation in Helicobacter pylori

Delany

Spohn

Rappuoli

et al. 2003

Molecular Microbiology

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SummaryThe Fur protein acts as a regulator of iron-dependent gene transcription in bacteria. In Helicobacter pylori , Fur regulates iron-activated and iron-repressed promoters. It also acts as an autoregulatory rheostat of transcription to fine-tune its own expression in response to iron by binding to three operators at its own promoter P fur . Using biochemical and genetic analyses, here we show that the distal upstream operator III (centred at ----110) is essential for iron regulation of P fur and functions as an anti-repression site that is bound by the iron-free form of Fur to induce transcription. Furthermore, operator I (centred at ----50) may have a dual role both as a high-affinity binding site for Fur and as an UP element. We propose that its role is ensuring that Fur expression is not repressed below a minimum threshold level. Our data supports a novel promoter architecture and mechanism of regulation by Fur.

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Section: Resultsmentioning

confidence: 99%

An anti‐repression Fur operator upstream of the promoter is required for iron‐mediated transcriptional autoregulation in Helicobacter pylori

Delany

Spohn

Rappuoli

et al. 2003

Molecular Microbiology

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“…One difference between the αCTD of E. coli and B. subtilis is that the E. coli protein possesses a 13‐amino‐acid C‐terminal sequence that is not found in the B. subtilis α. This C‐terminal peptide confers stability to the α subunit (Zou et al ., 1997). ClpXP might serve to provide stability to B. subtilis α that lacks this sequence.…”

Section: Discussionmentioning

confidence: 99%

Mutations conferring amino acid residue substitutions in the carboxy‐terminal domain of RNA polymerase α can suppress clpX and clpP with respect to developmentally regulated transcription in Bacillus subtilis

Nakano

Zhu

Liu

et al. 2000

Molecular Microbiology

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SummaryThe Bacillus subtilis clpX and clpP genes are the sites of pleiotropic mutations that adversely affect growth on a variety of media and impair developmental processes such as sporulation and competence development. ClpX is necessary for the postexponential induction of genes that require the s H form of RNA polymerase for transcription. Both ClpX and ClpP are required for the activation of s A -dependent transcription of the srf operon that encodes surfactin synthetase and the regulatory peptide ComS, required for the development of genetic competence. Transcription of srf is activated by the two-component regulatory system ComPA in response to the peptide pheromone, ComX, which mediates cell density-dependent control. A clpX mutant, although able to produce ComX, is unable to respond to the pheromone. A mutant allele of comP, encoding a product whose activity is independent of ComX, is not able to suppress clpX with respect to srf expression, suggesting that ClpXP acts at the level of ComA-dependent activation of srf transcription initiation. Suppressor mutations of clpX (cxs-1 and cxs-2) were isolated in screens for pseudorevertants exhibiting high levels of srf expression and s H -dependent transcription respectively.One mutation, cxs-1, suppressed a clpP null mutation with respect to srf transcription, but did not overcome the block conferred by clpP on competence development and sporulation. Both cxs-1 and cxs-2 mutations map to the region of the rpoA gene encoding the RNA polymerase a C-terminal domain (aCTD). The reconstruction of the cxs-1 and cxs-2 alleles of rpoA confirmed that these mutations confer the suppressor phenotype. These findings provide further support for the hypothesis that ClpX and ClpP might be intimately associated with transcription initiation in B. subtilis.

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“…Determination of the ratio of mutant to wild‐type α subunits in whole cells and in RNAP complexes was performed according to Zou et al . (1997).…”

Section: Methodsmentioning

confidence: 99%

The Escherichia coli RNA polymerase alpha subunit linker: length requirements for transcription activation at CRP-dependent promoters

et al. 2000

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). During transcription initiation at some promoters, Bristol BS8 1TD and 2 School of Biosciences, University of αCTD recognizes the AϩT-rich UP element (Ross et al., Birmingham, Birmingham B15 2TT, UK 1993; Giladi et al., 1996;Tagami and Aiba, 1999). At the 3 Corresponding author rrnB P1 promoter, this interaction is responsible for a e-mail: m.s.thomas@sheffield.ac.uk 30-to 70-fold increase in promoter activity (Ross et al., 1993;Rao et al., 1994;Estrem et al., 1998). In addition, The C-terminal domain of the Escherichia coli RNA αCTD is also a target for a variety of transcription activator polymerase α subunit (αCTD) plays a key role in proteins at positively regulated promoters, including the transcription initiation at many activator-dependent well studied cyclic AMP receptor protein (CRP; also promoters. This domain is connected to the N-terminal known as the catabolite activator protein, CAP) (reviewed domain by an unstructured linker, which is proposed by Ishihama, 1993; Ebright and Busby, 1995; Busby and to confer a high degree of mobility on αCTD. To Ebright, 1999). investigate the role of this linker in transcription CRP can activate transcription at Ͼ100 different proactivation we tested the effect of altering the linker moters in E.coli in response to the intracellular concentralength on promoters dependent on the cyclic AMP tion of its allosteric effector, cAMP (reviewed by Kolb receptor protein (CRP). Short deletions within Busby and Kolb, 1996). The cAMP-CRP α linker decrease CRP-dependent transcription at a complex binds as a dimer to a 22 bp inverted repeat, Class I promoter while increasing the activity of a possessing a consensus of aaaTGTGAtctagaTCACAttt Class II promoter. Linker extension impairs CRPdependent transcription from both promoters, with (Berg and von Hippel, 1988). The binding of the CRP short extensions exerting a more marked effect on dimer to its DNA target results in a sharp bend in the the Class II promoter. Activation at both classes of DNA (Wu and Crothers, 1984) estimated to be 80-90°p romoter was shown to remain dependent upon activat- (Schultz et al., 1991;Busby and Ebright, 1999). Promoters ing region 1 of CRP. These results show that the that are dependent upon CRP as sole activator can be response to CRP of RNA polymerase containing linkerdivided into two classes according to the location of the modified α subunits is class specific. These observations bound CRP (Ushida and Aiba, 1990;Ebright, 1993). At have important implications for the architecture of Class I CRP-dependent promoters, the CRP target site is transcription initiation complexes at CRP-dependent located upstream of the -35 region (at sites centred near promoters.positions -61.5, -71.5, -81.5 or -91.5 with respect to Keywords: α subunit/cyclic AMP receptor protein/interthe transcription start point), whereas at Class II CRPdomain linker/RNA polymerase/transcription activation dependent promoters the CRP-binding site is centred near position -41.5, and therefore overlaps the -35 region of the target...

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A nested set of C‐terminal deletions of the α subunit of Escherichia coli RNA polymerase define regions concerned with assembly, proteolysis, stabilization and transcriptional activation in vivo

Cited by 8 publications

References 45 publications

An anti‐repression Fur operator upstream of the promoter is required for iron‐mediated transcriptional autoregulation in Helicobacter pylori

An anti‐repression Fur operator upstream of the promoter is required for iron‐mediated transcriptional autoregulation in Helicobacter pylori

Mutations conferring amino acid residue substitutions in the carboxy‐terminal domain of RNA polymerase α can suppress clpX and clpP with respect to developmentally regulated transcription in Bacillus subtilis

The Escherichia coli RNA polymerase alpha subunit linker: length requirements for transcription activation at CRP-dependent promoters

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