Ppgpp
Mostrando 1-12 de 175 artigos, teses e dissertações.
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1. Estudo da regulação do gene cspD de Caulobacter crescentus. / The study of cspD gene regulation in Caulobacter crescentus.
CspD é uma das quatro proteínas de choque frio de Caulobacter crescentus, sendo maior que as outras CSPs por possuir dois domínios de choque frio, e tem seu papel na célula ainda desconhecido. O objetivo deste trabalho foi identificar e caracterizar os fatores in cis e in trans envolvidos na regulação da expressão do gene cspD em C. crescentus. Neste
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 28/11/2011
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2. Regulation of enteropathogenic Escherichia coli (EPEC) adhesion by genes related to nutrional shortage and stress. / Regulação da adesão de Escherichia coli enteropatogênica (EPEC) por genes de resposta à limitação nutricional e estresse.
Enteropathogenic E. coli (EPEC) is one of the causes of diarrhea in children. Phosphate (Pi) shortage induces transcription of the genes known as the PHO regulon. These genes are controlled by the Pst system, that is also a high-affinity Pi transporter, and represses PHO expression under Pi-replete conditions. PHO is also controlled by the two-component syst
Publicado em: 2009
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3. Identificação de genes de Azospirillum amazonense diferencialmente expressos em resposta à disponibilidade de nitrogênio
Bactérias do gênero Azospirillum possuem a capacidade de promover o crescimento vegetal através de mecanismos que não estão claramente elucidados. Contudo, essa característica é muito estudada, tendo em vista a possibilidade de utilizar esses microrganismos na agricultura em detrimento do uso indiscriminado de fertilizantes industriais, que poluem o m
Publicado em: 2008
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4. DksA Affects ppGpp Induction of RpoS at a Translational Level
The RpoS sigma factor (also called σS or σ38) is known to regulate at least 50 genes in response to environmental sources of stress or during entry into stationary phase. Regulation of RpoS abundance and activity is complex, with many factors participating at multiple levels. One factor is the nutritional stress signal ppGpp. The absence of ppGpp blocks or
American Society for Microbiology.
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5. Direct correlation between overproduction of guanosine 3',5'-bispyrophosphate (ppGpp) and penicillin tolerance in Escherichia coli.
The penicillin tolerance exhibited by amino acid-deprived Escherichia coli has been previously proposed to be a consequence of the stringent response. Evidence indicating that penicillin tolerance is directly attributable to guanosine 3',5'-bispyrophosphate (ppGpp) overproduction and not to some other effect of amino acid deprivation is now presented. Accumu
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6. Occurrence of the regulatory nucleotides ppGpp and pppGpp following induction of the stringent response in staphylococci.
The stringent response in Escherichia coli and many other organisms is regulated by the nucleotides ppGpp and pppGpp. We show here for the first time that at least six staphylococcal species also synthesize ppGpp and pppGpp upon induction of the stringent response by mupirocin. Spots corresponding to ppGpp and pppGpp on thin-layer chromatograms suggest that
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7. Identification of the bacterial alarmone guanosine 5′-diphosphate 3′-diphosphate (ppGpp) in plants
Stringent control mediated by the bacterial alarmone guanosine 5′-diphosphate 3′-diphosphate (ppGpp) is a key regulatory process governing bacterial gene expression. By devising a system to measure ppGpp in plants, we have been able to identify ppGpp in the chloroplasts of plant cells. Levels of ppGpp increased markedly when plants were subjected to such
National Academy of Sciences.
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8. Degradation of ppGpp by Nudix Pyrophosphatase Modulates the Transition of Growth Phase in the Bacterium Thermus thermophilus*
A major bacterial alarmone, guanosine 3′,5′-bispyrophosphate (ppGpp), controls cellular growth under conditions of nutritional starvation. For most bacteria, intracellular ppGpp levels are tightly controlled by the synthesis/degradation cycle of RelA and SpoT activities. This study shows a novel ppGpp regulatory protein governing the cellular growth of T
American Society for Biochemistry and Molecular Biology.
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9. Promoter selectivity of Escherichia coli RNA polymerase: omega factor is responsible for the ppGpp sensitivity.
Transcription in vitro of stringently controlled Escherichia coli genes by purified RNA polymerase holoenzyme is inhibited by guanosine tetraphosphate (ppGpp). In order to examine possible role of omega factor in this ppGpp sensitivity, RNA polymerases with or without the omega factor were reconstituted and tested for their ppGpp sensitivity using an in vitr
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10. Influence of amino acid starvation on guanosine 5'-diphosphate 3'-diphosphate basal-level synthesis in Escherichia coli.
We observed that the synthesis of basal-level guanosine 5'-diphosphate 3'-diphosphate (ppGpp) in both relA mutants and relA+ relC strains of Escherichia coli decreased in response to amino acid limitation and that this was accompanied by an increase in ribonucleic acid (RNA) synthesis. Addition of the required amino acid to starved cultures of relaxed bacter
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11. Synthesis of guanosine tetra- and pentaphosphates by the obligately anaerobic bacterium Bacteroides thetaiotaomicron in response to molecular oxygen.
Guanosine 5'-diphosphate 3'-diphosphate (ppGpp) and guanosine 5'-triphosphate 3'-diphosphate (pppGpp) were detected in formic acid extracts of air-exposed culutres of Bacteroides thetaiotaomicron. The identification of ppGpp and pppGpp in B. thetaiotaomicron was based on the following results: (i) cochromatography of 32P-labeled hyperphosphorylated nucleotid
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12. Synthesis of the stationary-phase sigma factor sigma s is positively regulated by ppGpp.
Strains of Escherichia coli which lack detectable guanosine 3',5'-bispyrophosphate (ppGpp) display a pleiotropic phenotype that in some respects resembles that of rpoS (katF) mutants. This led us to examine whether ppGpp is a positive regulator of sigma s synthesis. sigma s is a stationary-phase-specific sigma factor that is encoded by the rpoS gene. We foun