Factor-independent activation of Escherichia coli rRNA transcription

1991 ◽  
Vol 220 (3) ◽  
pp. 555-568 ◽  
Author(s):  
Sigrid Leirmo ◽  
Richard L. Gourse
Keyword(s):  
Escherichia Coli ◽  
Rrna Transcription

scholarly journals Control of rRNA transcription in Escherichia coli.

1995 ◽  
Vol 59 (4) ◽  
pp. 623-645 ◽  
Author(s):  
C Condon ◽  
C Squires ◽  
C L Squires
Keyword(s):  
Escherichia Coli ◽  
Rrna Transcription

scholarly journals rRNA transcription rate in Escherichia coli.

1991 ◽  
Vol 173 (20) ◽  
pp. 6647-6649 ◽  
Author(s):  
S L Gotta ◽  
O L Miller ◽  
S L French
Keyword(s):  
Escherichia Coli ◽  
Transcription Rate ◽  
Rrna Transcription

scholarly journals In Vivo Effect of NusB and NusG on rRNA Transcription Antitermination

2004 ◽  
Vol 186 (5) ◽  
pp. 1304-1310 ◽  
Author(s):  
Martha Torres ◽  
Joan-Miquel Balada ◽  
Malcolm Zellars ◽  
Craig Squires ◽  
Catherine L. Squires
Keyword(s):  
Escherichia Coli ◽  
Rna Polymerase ◽  
Protein Complex ◽  
Test System ◽  
Wild Type ◽  
Rrna Transcription ◽  
Transcription Antitermination ◽  
Gene Mrna

ABSTRACT Similarities between lambda and rRNA transcription antitermination have led to suggestions that they involve the same Nus factors. However, direct in vivo confirmation that rRNA antitermination requires all of the lambda Nus factors is lacking. We have therefore analyzed the in vivo role of NusB and NusG in rRNA transcription antitermination and have established that both are essential for it. We used a plasmid test system in which reporter gene mRNA was measured to monitor rRNA antiterminator-dependent bypass of a Rho-dependent terminator. A comparison of terminator read-through in a wild-type Escherichia coli strain and that in a nusB::IS10 mutant strain determined the requirement for NusB. In the absence of NusB, antiterminator-dependent terminator read-through was not detected, showing that NusB is necessary for rRNA transcription antitermination. The requirement for NusG was determined by comparing rRNA antiterminator-dependent terminator read-through in a strain overexpressing NusG with that in a strain depleted of NusG. In NusG-depleted cells, termination levels were unchanged in the presence or absence of the antiterminator, demonstrating that NusG, like NusB, is necessary for rRNA transcription antitermination. These results imply that NusB and NusG are likely to be part of an RNA-protein complex formed with RNA polymerase during transcription of the rRNA antiterminator sequences that is required for rRNA antiterminator-dependent terminator read-through.

scholarly journals Activation of Escherichia coli rRNA Transcription by FIS during a Growth Cycle

1998 ◽  
Vol 180 (6) ◽  
pp. 1525-1532 ◽  
Author(s):  
J. Alex Appleman ◽  
Wilma Ross ◽  
Julia Salomon ◽  
Richard L. Gourse
Keyword(s):  
Escherichia Coli ◽  
Site Occupancy ◽  
Growth Conditions ◽  
Growth Cycle ◽  
Rrna Synthesis ◽  
Rrna Transcription ◽  
Low Culture ◽  
State Growth ◽  
In Vivo Footprinting

ABSTRACT rRNA transcription in Escherichia coli is activated by the FIS protein, which binds upstream of rrnp 1promoters and interacts directly with RNA polymerase. Analysis of the contribution of FIS to rrn transcription under changing physiological conditions is complicated by several factors: the wide variation in cellular FIS concentrations with growth conditions, the contributions of several other regulatory systems to rRNA synthesis, and the pleiotropy of fis mutations. In this report, we show by in vivo footprinting and Western blot analysis that occupancy of the rrnBp 1 FIS sites correlates with cellular levels of FIS. We find, using two methods of measurement (pulse induction of a FIS-activated hybrid promoter and primer extension from an unstable transcript made fromrrnBp 1), that the extent of transcription activation by FIS parallels the degree of FIS site occupancy and therefore cellular FIS levels. FIS activates transcription throughout exponential growth at low culture density, butrrnp 1 transcription increases independently of FIS immediately following upshift, before FIS accumulates. These results support the model that FIS is one of a set of overlapping signals that together contribute to transcription fromrrnp 1 promoters during steady-state growth.

scholarly journals Increased rrn Gene Dosage Causes Intermittent Transcription of rRNA in Escherichia coli

1999 ◽  
Vol 181 (14) ◽  
pp. 4170-4175 ◽  
Author(s):  
Justina Voulgaris ◽  
Sarah French ◽  
Richard L. Gourse ◽  
Craig Squires ◽  
Catherine L. Squires
Keyword(s):  
Escherichia Coli ◽  
Rna Polymerase ◽  
Gene Dosage ◽  
Transcription Termination ◽  
Elongation Rate ◽  
Multicopy Plasmid ◽  
Constant Concentration ◽  
Time Intervals ◽  
Rrna Transcription ◽  
Irregular Spacing

ABSTRACT When the number of rRNA (rrn) operons in anEscherichia coli cells is increased by adding anrrn operon on a multicopy plasmid, the rate of rRNA expression per operon is reduced to maintain a constant concentration of rRNA in the cell. We have used electron microscopy to examine rRNA transcription in cells containing a multicopy plasmid carryingrrnB. We found that there were fewer RNA polymerase molecules transcribing the rrn genes, as predicted from previous gene dosage studies. Furthermore, RNA polymerase molecules were arranged in irregularly spaced groups along the operon. No apparent pause or transcription termination sites that would account for the irregular spacing of the groups of polymerase molecules were observed. We also found that the overall transcription elongation rate was unchanged when the rrn gene dosage was increased. Our data suggest that when rrn gene dosage is increased, initiation events, or promoter-proximal elongation events, are interrupted at irregular time intervals.

scholarly journals Spatial organization of RNA polymerase and its relationship with transcription in Escherichia coli

2019 ◽  
Vol 116 (40) ◽  
pp. 20115-20123 ◽  
Author(s):  
Xiaoli Weng ◽  
Christopher H. Bohrer ◽  
Kelsey Bettridge ◽  
Arvin Cesar Lagda ◽  
Cedric Cagliero ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Rna Polymerase ◽  
Growth Condition ◽  
Spatial Organization ◽  
Large Fraction ◽  
Spatial Arrangement ◽  
Rrna Synthesis ◽  
Rich Medium ◽  
Transcription Activity ◽  
Rrna Transcription

Recent studies have shown that RNA polymerase (RNAP) is organized into distinct clusters in Escherichia coli and Bacillus subtilis cells. Spatially organized molecular components in prokaryotic systems imply compartmentalization without the use of membranes, which may offer insights into unique functions and regulations. It has been proposed that the formation of RNAP clusters is driven by active ribosomal RNA (rRNA) transcription and that RNAP clusters function as factories for highly efficient transcription. In this work, we examined these hypotheses by investigating the spatial organization and transcription activity of RNAP in E. coli cells using quantitative superresolution imaging coupled with genetic and biochemical assays. We observed that RNAP formed distinct clusters that were engaged in active rRNA synthesis under a rich medium growth condition. Surprisingly, a large fraction of RNAP clusters persisted in the absence of high rRNA transcription activities or when the housekeeping σ70 was sequestered, and was only significantly diminished when all RNA transcription was inhibited globally. In contrast, the cellular distribution of RNAP closely followed the morphology of the underlying nucleoid under all conditions tested irrespective of the corresponding transcription activity, and RNAP redistributed into dispersed, smaller clusters when the supercoiling state of the nucleoid was perturbed. These results suggest that RNAP was organized into active transcription centers under the rich medium growth condition; its spatial arrangement at the cellular level, however, was not dependent on rRNA synthesis activity and was likely organized by the underlying nucleoid.

scholarly journals Control of rRNA transcription in Escherichia coli.

1995 ◽  
Vol 59 (4) ◽  
pp. 623-645 ◽  
Author(s):  
C Condon ◽  
C Squires ◽  
C L Squires
Keyword(s):  
Escherichia Coli ◽  
Rrna Transcription

scholarly journals Identification of promoter mutants defective in growth-rate-dependent regulation of rRNA transcription in Escherichia coli.

1989 ◽  
Vol 171 (9) ◽  
pp. 4862-4870 ◽  
Author(s):  
R R Dickson ◽  
T Gaal ◽  
H A deBoer ◽  
P L deHaseth ◽  
R L Gourse
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Rate Dependent ◽  
Rrna Transcription

scholarly journals Regulation of rRNA Transcription Is Remarkably Robust: FIS Compensates for Altered Nucleoside Triphosphate Sensing by Mutant RNA Polymerases at Escherichia coli rrn P1 Promoters

2000 ◽  
Vol 182 (7) ◽  
pp. 1969-1977 ◽  
Author(s):  
Michael S. Bartlett ◽  
Tamas Gaal ◽  
Wilma Ross ◽  
Richard L. Gourse
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Transcription Initiation ◽  
Rrna Synthesis ◽  
Nucleoside Triphosphate ◽  
Wild Type ◽  
Core Promoters ◽  
Rate Dependent ◽  
Rrna Transcription

ABSTRACT We recently identified Escherichia coli RNA polymerase (RNAP) mutants (RNAP β′ Δ215–220 and β RH454) that form extremely unstable complexes with rRNA P1 (rrn P1) core promoters. The mutant RNAPs reduce transcription and alter growth rate-dependent regulation of rrn P1 core promoters, because the mutant RNAPs require higher concentrations of the initiating nucleoside triphosphate (NTP) for efficient transcription from these promoters than are present in vivo. Nevertheless, the mutants grow almost as well as wild-type cells, suggesting that rRNA synthesis is not greatly perturbed. We report here that the rrntranscription factor FIS activates the mutant RNAPs more strongly than wild-type RNAP, thereby compensating for the altered properties of the mutant RNAPs. FIS activates the mutant RNAPs, at least in part, by reducing the apparent K ATP for the initiating NTP. This and other results suggest that FIS affects a step in transcription initiation after closed-complex formation in addition to its stimulatory effect on initial RNAP binding. FIS and NTP levels increase with growth rate, suggesting that changing FIS concentrations, in conjunction with changing NTP concentrations, are responsible for growth rate-dependent regulation of rrn P1 transcription in the mutant strains. These results provide a dramatic demonstration of the interplay between regulatory mechanisms in rRNA transcription.

Sign in / Sign up

Export Citation Format

Share Document