Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 20 for “"stringent response"”.
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Relative contributions of the stringent response mediators (p)ppGpp and DksA to Haemophilus ducreyi virulence in humans
… ducreyi is subject to a variety of stresses. The stringent response is a bacterial stress response system induced by nutrient limiting conditions and mediated by guanosine tetra- and pentaphosphate [(p)ppGpp] and the transcriptional regulator DksA. (p)ppGpp and DksA jointly interact with RNA …
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Structural and Functional Studies on the Escherichia coli Inducible Lysine Decarboxylase: Linking the Acid Stress and Stringent Responses
The Escherichia coli acid stress response allows the survival of cells over a wide range of pH challenges: down to pH 2.0 with the extreme acid stress response and down to pH 4.0 – 5.0 with the mild acid stress response. The cell employs a number of different acid stress response systems, including …
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Development of in vivo ppGpp reporters in escherichia coli
… the E. coli physiology, most notably during the stringent response. Systems biology studies have emphasized its role in understanding the host response to the burden of introduced synthetic genetic circuits. Traditionally, researchers rely on in vitro methods to measure the intracellular ppGpp …
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Parallel algorithms for convex hulls and proximity problems
… often have both intense computational needs and stringent response time requirements. Motivated by these concerns, this thesis investigates parallel algorithms for some basic geometric problems. The model of parallel computation used in our studies is the Parallel Random Access Machine (CREW …
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Evolution and Regulation of Virulence and Antimicrobial Resistance in Pseudomonas aeruginosa
… rhl and pqs), which are in turn modulated by the Stringent Response (SR). This system allows bacteria to sense and respond to nutrient limitations and related stresses by modulating cellular transcription patterns. Notably, it has always been assumed that the stringent response is essential for …
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REGULATORY PROCESSES IN ULTRA SLOW GROWING MICROORGANISMS (ESCHERICHIA COLI, BACILLUS POLYMYXA)
… prolonged state of regulation by the stringent response. The length of growth phase 2 was changed substantially by mutations in the relA, relX, and spoT loci, in ways which are exactly predictable from their effects on ppGpp synthesis, as phase 2 was longer for mutants with a decreased …
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Characterization of beneficial mutations in unsaturated fatty acid biosynthesis that are recurrent dead-ends in a long-term evolution experiment with Escherichia coli
… successful clades is within the stress response global regulator spoT. A connection between spoT and fabR mutations could be the key to understanding the eventual outcomes within these lineages. Decreased fatty acid synthesis (repressed by FabR) during glucose starvation activates the …
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Studies on the regulation of aspartokinase II from Bacillus subtilis
… methods to be regulated by degradation in response to starvation of cells for various nutrients. Ammonium starvation induced the fastest aspartokinase II decline (t$\sb{1/2}$ = 65 min), followed by amino acid starvation (t$\sb{1/2}$ = 80 min), and glucose limitation (t$\sb{1/2}$ = 120 min). …
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The role of highly phosphorylated nucleotides in the development of bacterial resistance to antibiotics
… and early stationary phases of growth, in response to adverse nutritional conditions. These compounds are involved in the phenomena of endosporulation and stringent response which both elicit an increase in observed antibiotic resistance in many bacterial species. It is thought that HPNs …
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Scheduling policies for disks and disk arrays
… common in OLTP applications, which tend to have stringent response time requirements. Scheduling of disk requests is intended to improve their response time, reduce disk service time, and increase disk access bandwidth with respect to the default FCFS scheduling policy. Shortest Access Time First …
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THE EFFECT OF STRINGENT CONTROL ON THE PRODUCTION OF ENTEROTOXIN, TRYPTOPHANASE, AND BETA-GALACTOSIDASE BY ESCHERICHIA COLI IN A RECYCLING FERMENTOR
… shown to be initiated by the induction of the stringent response and to be regulated by the levels of guanosine 5'-diphosphate 3'-diphosphate (ppGpp) within the cell. By comparing the growth patterns of three enterotoxigenic Escherichia coli strains to that of E. coli strains of known rel …
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Uncovering the Redox Potential of the Global Gene Regulatory Protein DksA in Borrelia burgdorferi
… the expression of housekeeping genes during the stringent response, while promoting the expression of virulence genes during infection. The mechanistic details of how DksA is able to sense environmental signals in B. burgdorferi is poorly understood. DksA harbors a conserved zinc finger motif, …
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A model for sigma factor competition in bacterial cells
… the global pattern of expressed genes. In response to specific environmental stresses the cell activates several stress-specific molecules such as sigma factors. They reversibly bind the RNA polymerase to form the so-called holoenzyme and direct it towards the appropriate stress response …
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Characterization of Bacterial Transcriptional Regulatory Networks through Genome-Wide in vitro Run-Off Transcription RNA-Seq (ROSE)
… /> Furthermore, ROSE was utilized to analyze the stringent response mechanism in E. coli K-12 MG1655. The protein DksA and the alarmone ppGpp were added to extend the ROSE method, resulting in 2,205 TSS with differential transcription activity of at least twofold in the presence of DksA+ppGpp. Out …
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Transcription in Mycoplasma pneumoniae
Das humanpathogene Bakterium Mycoplasma pneumoniae besitzt lediglich ein kleines Repertoire von Genen, die vermutlich an der Transkriptionsregulation beteiligt sind. Dieser Umstand reflektiert seine Anpassung an ein nährstoffreiches Habitat mit konstanten Umweltbedingungen, dem menschlichen …
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Combinatorial search strategies for the metabolic engineering of microorganisms
… linking this phenotype to two different cellular responses -- the acid stress resistance pathway and the stringent response. Indeed, the overexpression of two transcriptional regulators for these pathways (evgA, relA) was able to supplant the need for the mutant rpoA or rpoD plasmids, thus …