Synthesis of guanosine tetra- and pentaphosphates by the obligately anaerobic bacterium Bacteroides thetaiotaomicron in response to molecular oxygen

Glass, Thomas L.; Holmes, W M; Hylemon, Phillip B.; Stellwag, Edmund J.

doi:10.1128/jb.137.2.956-962.1979

Cited by 26 publications

(13 citation statements)

References 16 publications

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“…The NAD+-linked enzyme may have a catabolic function, whereas the NADP+-dependent activity is involved in glutamate biosynthesis (4,36). It is not obvious what function(s) a catabolic NAD+-linked glutamate dehydrogenase would serve in B. thetaiotaomicron, since glutamate is not used as a carbon, nitrogen, or energy source (39), nor is it incorporated into cellular material (15). Rather, the nitrogen requirement for NH4Cl implies a need for glutamate biosynthesis which could be fulfilled by the NADPH-linked glutamate dehydrogenase activity.…”

Section: Resultsmentioning

confidence: 99%

“…This is indicated by the high Sos values for NAD+ and glutamate as well as the inhibitory effects of numerous compounds (including anions). As noted previously, B. thetaiotaomicron does not assimilate glutamate from the growth medium (15). Therefore, the physiological significance, if any, of the NAD+-linked glutamate oxidation is not known.…”

Section: Glass and Hylemonmentioning

confidence: 91%

“…B. thetaiotaomicron VPI 5482 and all other Bacteroides strains were obtained from the Anaerobe Laboratory, Virginia Polytechnic Institute and State University, Blacksburg. The bacteria were grown in the defined basal medium of Varel and Bryant (39) with L-methionine (75 mg/liter) instead of vitamin B12, 3 mM (NH4)2804, 15 mM glucose, and an atmosphere of 100% N2 or argon, using previously described anaerobic procedures (16).…”

Section: Methodsmentioning

confidence: 99%

“…The culture was harvested in the late log phase (180 Klett units) by centrifugation (12,000 x g, 20 min, 0C). The pellets were suspended in 0.1 M Tris-hydrochloride (pH 8.0) plus 10 mM 2-mercaptoethanol (2-ME) (buffer A) and centrifuged (26,000 x g, 15 min, 0C). The cell pellet was then stored overnight at -20°C.…”

Section: Methodsmentioning

confidence: 99%

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Characterization of a pyridine nucleotide-nonspecific glutamate dehydrogenase from Bacteroides thetaiotaomicron

Glass¹,

Hylemon²

1980

J Bacteriol

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An oxidized nicotinamide adenine dinucleotide phosphate/oxidized nicotinamide adenine dinucleotide (NADP+/NAD+) nonspecific L-glutamate dehydrogenase from Bacteroides thetaiotaomicron was purified 40-fold (NADP+ or NAD+ activity) over crude cell extract by heat treatment, (NH4)2S02 fractionation, diethylaminoethyl-cellulose, Bio-Gel A 1.5m, and hydroxylapatite chromatography. Both NADP+and NAD+-dependent activities coeluted from all chromatographic treatments. Moreover, a constant ratio of NADP+/NAD+ specific activities was demonstrated at each purification step. Both activities also comigrated in 6% nondenaturing polyacrylamide gels. Affinity chromatography of the 40-fold-purified enzyme using Procion RED HE-3B gave a preparation containing both NADP+-and NAD+-linked activities which showed a single protein band of 48,500 molecular weight after sodium dodecyl sulfate-polyacrylamide gradient gel electrophoresis. The dual pyridine nucleotide nature of the enzyme was most readily apparent in the oxidative direction. Reductively, the enzyme was 30-fold more active with reduced NADP than with reduced NAD. Nonlinear concave 1/ V versus 1/S plots were observed for reduced NADP and NH4CL Salts (0.1 M) stimulated the NADP+-linked reaction, inhibited the NAD+-linked reaction, and had little effect on the reduced NADP-dependent reaction. The stimulatory effect of salts (NADP+) was nonspecific, regardless of the anion or cation, whereas the degree of NAD+-linked inhibition decreased in the order of 1-> Br-> C1-> F-. Both NADP+ and NAD+ glutamate dehydrogenase activities were also detected in cell extracts from representative strains of other bacteroides deoxyribonucleic acid homology groups.

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Section: Resultsmentioning

confidence: 99%

Section: Glass and Hylemonmentioning

confidence: 91%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Characterization of a pyridine nucleotide-nonspecific glutamate dehydrogenase from Bacteroides thetaiotaomicron

Glass¹,

Hylemon²

1980

J Bacteriol

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“…18,19 The intracellular alarmones, guanosine 5′-diphosphate 3′-diphosphate (ppGpp) and guanosine 5′-triphosphate 3′-diphosphate (pppGpp), are key signaling molecules that enable cell homeostasis. 20 It has been reported that changes in the intracellular level of (p)ppGpp can be triggered by various environmental perturbations, including changes in nutrient availability, 21 redox, 22 pH, 23 and temperature. 24 The cellular stress response mediated by the increased level of (p)ppGpp is commonly referred to as the stringent response.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of ppGpp impacts type IX secretion and biofilm matrix formation in Porphyromonas gingivalis

Kim

Davey

2020

npj Biofilms Microbiomes

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In order to persist, bacteria need to adjust their physiological state in response to external and internal cues. External stimuli are often referred to as stressors. The stringent response, mediated by the alarmone (p)ppGpp, is central to the stress response in many bacteria; yet, there is limited knowledge regarding the role of (p)ppGpp signaling in bacteria belonging to the phylum Bacteroidetes. Like its counterparts in the gut (e.g., Bacteroides thetaiotaomicron and Bacteroides fragilis), Porphyromonas gingivalis persists in close association with its human host. Given the potential for numerous perturbations in the oral cavity, and the fact that P. gingivalis can enter and replicate within host cells, we hypothesized that (p)ppGpp is a key signaling molecule for stress adaptation and persistence. Here, we show that accumulation of ppGpp in P. gingivalis is governed by two homologous enzymes, designated Rel, and RshB, and that ppGpp signaling affects growth rate, survival, biofilm formation, production of outer membrane vesicles, and expression of genes encoding type IX secretion structural and cargo proteins. Overall, our findings provide a potential mechanism by which biofilm formation and virulence of P. gingivalis are integrated via ppGpp signaling, a regulatory mechanism central to bacterial survival in dynamic environments.npj Biofilms and Microbiomes (2020) 6:5 ; https://doi.

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Nucleosidpolyphosphate: Vorkommen, Metabolismus und Funktion

Riedel¹

1983

J of Basic Microbiology

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Procaryotes have regulatory systems allowing to vary the metabolism in response to nutritional variations, to reduce the growth, and to start development. Nucleoside polyphosphates are mediators of coordinated alterations of metabolism. In this review, after a brief recall of the characteristics of the stringent response, the occurrence, determinations, and the metabolism of the nucleoside polyphosphates are presented. The representation of the pleiotropic effects includes the regulation of the protein synthesis and of the protein synthesis apparatus, of the protein turnover, of the N‐ and carbohydrate metabolism, of the formation of cell membranes and cell walls as well as the possible function of the development.

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Synthesis of guanosine tetra- and pentaphosphates by the obligately anaerobic bacterium Bacteroides thetaiotaomicron in response to molecular oxygen

Cited by 26 publications

References 16 publications

Characterization of a pyridine nucleotide-nonspecific glutamate dehydrogenase from Bacteroides thetaiotaomicron

Characterization of a pyridine nucleotide-nonspecific glutamate dehydrogenase from Bacteroides thetaiotaomicron

Synthesis of ppGpp impacts type IX secretion and biofilm matrix formation in Porphyromonas gingivalis

Nucleosidpolyphosphate: Vorkommen, Metabolismus und Funktion

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