The plastid rpoA gene encoding a protein homologous to the bacterial RNA polymerase alpha subunit is expressed in pea chloroplasts

1989 ◽  
Vol 217 (1) ◽  
pp. 77-84 ◽  
Author(s):  
Saul Purton ◽  
John C. Gray
Keyword(s):  
Rna Polymerase ◽  
Alpha Subunit ◽  
Gene Encoding ◽  
Bacterial Rna ◽  
Rpoa Gene

scholarly journals Mutagenesis of the Bacterial RNA Polymerase Alpha Subunit for Improvement of Complex Phenotypes

2009 ◽  
Vol 75 (9) ◽  
pp. 2705-2711 ◽  
Author(s):  
Daniel Klein-Marcuschamer ◽  
Christine Nicole S. Santos ◽  
Huimin Yu ◽  
Gregory Stephanopoulos
Keyword(s):  
Rna Polymerase ◽  
Underlying Mechanism ◽  
Strain Engineering ◽  
Alpha Subunit ◽  
Physiological Changes ◽  
Core Enzyme ◽  
Complex Phenotypes ◽  
Bacterial Rna ◽  
Tolerant Mutant ◽  
Solvent Tolerant

ABSTRACT Combinatorial or random methods for strain engineering have been extensively used for the improvement of multigenic phenotypes and other traits for which the underlying mechanism is not fully understood. Although the preferred method has traditionally been mutagenesis and selection, our laboratory has successfully used mutant transcription factors, which direct the RNA polymerase (RNAP) during transcription, to engineer complex phenotypes in microbial cells. Here, we show that it is also possible to impart new phenotypes by altering the RNAP core enzyme itself, in particular through mutagenesis of the alpha subunit of the bacterial polymerase. We present the use of this tool for improving tolerance of Escherichia coli to butanol and other solvents and for increasing the titers of two commercially relevant products, l-tyrosine and hyaluronic acid. In addition, we explore the underlying physiological changes that give rise to the solvent-tolerant mutant.

scholarly journals The Phage-Encoded N-Acetyltransferase Rac Mediates Inactivation of Pseudomonas aeruginosa Transcription by Cleavage of the RNA Polymerase Alpha Subunit

Viruses ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 976 ◽  
Author(s):  
Pieter-Jan Ceyssens ◽  
Jeroen De Smet ◽  
Jeroen Wagemans ◽  
Natalia Akulenko ◽  
Evgeny Klimuk ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Rna Polymerase ◽  
Transcription Initiation ◽  
Alpha Subunit ◽  
Regulation Mechanism ◽  
Post Translational Modification ◽  
Α Subunit ◽  
Bacterial Transcription ◽  
Highly Active ◽  
Bacterial Rna

In this study, we describe the biological function of the phage-encoded protein RNA polymerase alpha subunit cleavage protein (Rac), a predicted Gcn5-related acetyltransferase encoded by phiKMV-like viruses. These phages encode a single-subunit RNA polymerase for transcription of their late (structure- and lysis-associated) genes, whereas the bacterial RNA polymerase is used at the earlier stages of infection. Rac mediates the inactivation of bacterial transcription by introducing a specific cleavage in the α subunit of the bacterial RNA polymerase. This cleavage occurs within the flexible linker sequence and disconnects the C-terminal domain, required for transcription initiation from most highly active cellular promoters. To achieve this, Rac likely taps into a novel post-translational modification (PTM) mechanism within the host Pseudomonas aeruginosa. From an evolutionary perspective, this novel phage-encoded regulation mechanism confirms the importance of PTMs in the prokaryotic metabolism and represents a new way by which phages can hijack the bacterial host metabolism.

scholarly journals Identification and characterization of pleiotropic high-persistence mutations in the beta subunit of the bacterial RNA polymerase

2020 ◽  
Author(s):  
Lev Ostrer ◽  
Yinduo Ji ◽  
Arkady Khodursky
Keyword(s):  
Antibiotic Resistance ◽  
Rna Polymerase ◽  
Low Frequency ◽  
Beta Subunit ◽  
Resistance Mutations ◽  
Chronic Infections ◽  
Gene Encoding ◽  
Bacterial Populations ◽  
Bacterial Rna ◽  
Transcriptional Changes

AbstractIndividual bacteria can escape killing by bactericidal antibiotics by becoming dormant. Such cells, also known as persisters, naturally occur in bacterial populations at a low frequency. Here we present the finding that antibiotic-resistance mutations in the rpoB gene, encoding the beta subunit of RNA polymerase, increase the frequency of persisters by orders of magnitude. Furthermore, we show that: i) the persistent state depends on the (p)ppGpp transcriptional program and not on (p)ppGpp itself; ii) the high persistence (hip) is associated with increased populational heterogeneity in transcription; iii) indole overproduction, caused by transcriptional changes in the hip mutants, explains 50-80% of the hip phenotype. We report that the analogous rpoB mutations occur frequently in clinical isolates of Acinetobacter baumannii, Mycobacterium tuberculosis and Staphylococcus aureus, and we demonstrate that one of those rpoB mutations causes high persistence in MRSA. We also show that the RpoB-associated hip phenotype can be reversed by inhibiting protein synthesis.ImportancePersistence is an inevitable consequence of antibiotic usage. Although persistence is not a genetically heritable trait, here we demonstrate for the first time that antibiotic resistance, which is heritable, can promote persistence formation. Our finding that resistance to one antibiotic, rifampicin, can boost persistence to other antibiotics, such as ciprofloxacin and ampicillin, may help explain why certain chronic infections are particularly recalcitrant to antibiotic therapies. Out results also emphasize the need to assess the effects of combination antibiotic therapies on persistence.

scholarly journals The Escherichia coli RNA polymerase alpha subunit and transcriptional activation by bacteriophage lambda CII protein.

1998 ◽  
Vol 45 (1) ◽  
pp. 271-280 ◽  
Author(s):  
M Gabig ◽  
M Obuchowski ◽  
A Ciesielska ◽  
B Latała ◽  
A Wegrzyn ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Rna Polymerase ◽  
Transcriptional Activation ◽  
Bacteriophage Lambda ◽  
Alpha Subunit ◽  
Single Amino Acid ◽  
Amino Acid Residues ◽  
A Subunit ◽  
Rpoa Gene

Bacteriophage lambda is not able to lysogenise the Escherichia coli rpoA341 mutant. This mutation causes a single amino acid substitution Lys271Glu in the C-terminal domain of the RNA polymerase alpha subunit (alphaCTD). Our previous studies indicated that the impaired lysogenisation of the rpoA341 host is due to a defect in transcriptional activation by the phage CII protein and suggested a role for alphaCTD in this process. Here we used a series of truncation and point mutants in the rpoA gene placed on a plasmid to investigate the process of transcriptional activation by the cII gene product. Our results indicate that amino-acid residues 265, 268 and 271 in the a subunit may play an important role in the CII-mediated activation of the pE promoter (most probably residue 271) or may be involved in putative interactions between alphaCTD and an UP-like element near pE (most probably residues 265 and 268). Measurement of the activity of pE-lacZ, pI-lacZ and p(aQ)-lacZ fusions in the rpoA+ and rpoA341 hosts demonstrated that the mechanism of activation of these CII-dependent promoters may be in each case different.

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