A changed nitrogenase activity in Rhodospirillum rubrum after substitution of tungsten for molybdenum

Paschinger, H.

doi:10.1007/bf00455954

Cited by 17 publications

(10 citation statements)

References 15 publications

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“…Cells were grown on Ormerod's medium as modified by Kanemoto and Ludden (18) with glutamate as the nitrogen source; molybdenum was left out of the medium, and 1 mM NaWO 4 was added to the medium to suppress the synthesis of any iron-molybdenum cofactor. Paschinger (26) had shown that R. rubrum is resistant to WO 4 2Ϫ , and Lehman and Roberts (21) noted that it was not necessary to scrub the medium of MoO 4 2Ϫ in order to observe synthesis of the alternative nitrogenase. Cells were grown in a 100-liter illuminated fermentor at 30ЊC to an A 600 of approximately 1.2.…”

Section: Methodsmentioning

confidence: 99%

Purification and characterization of the alternative nitrogenase from the photosynthetic bacterium Rhodospirillum rubrum

et al. 1996

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The alternative nitrogenase from a nifH mutant of the photosynthetic bacterium Rhodospirillum rubrum has been purified and characterized. The dinitrogenase protein (ANF1) contains three subunits in an apparent ␣ 2 ␤ 2 ␥ 2 structure and contains Fe but no Mo or V. A factor capable of activating apo-dinitrogenase (lacking the FeMo cofactor) from Azotobacter vinelandii was extracted from the alternative dinitrogenase protein with N-methylformamide. The electron paramagnetic resonance (EPR) signal of the dinitrogenase protein is not characteristic of the EPR signals of molybdenum-or vanadium-containing dinitrogenases. The alternative dinitrogenase reductase (ANF2) was purified as an ␣ 2 dimer containing an Fe 4 S 4 cluster and exhibited an EPR spectrum characteristic of dinitrogenase reductases. The enzyme complex reduces protons to H 2 very well but reduces N 2 to ammonium poorly. Acetylene is reduced to a mixture of ethylene and ethane.

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Section: Methodsmentioning

confidence: 99%

Purification and characterization of the alternative nitrogenase from the photosynthetic bacterium Rhodospirillum rubrum

et al. 1996

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“…While these are assumed to be inactive apo-or W-substituted proteins, several studies have indicated the formation of active W [205] or mixed W-Mo-nitrogenases [206]. The first report of this type was in 1974 [207] Unfortunately, the nitrogenase from W-grown cells has not been characterized [207]. W-rather than Mo-dependent growth has also been reported for a mutant strain of A. vinelandii (WN 101; [205]).…”

Section: Nitrogen-fixing Bacteriamentioning

confidence: 99%

“…The metabolism of W by plants has been studied almost exclusively with reference to its effect on two molybdoenzymes of high agricultural significance: assimilatory nitrate reductase (NR) in the plants themselves and nitrogenase in symbiotic rhizobia [13,24,189,200,207,238]. In fact, it is in this context that some of the earliest, and often most contradictory references to the biological effects of W can be found.…”

Section: Plantsmentioning

confidence: 99%

“…It has been known for many years that W is a competitive inhibitor for the expression of active nitrogenase [191][192][193]193,199], that W is incorporated into the enzyme [24,200,201,207], and that there are some W-resistant bacterial strains [208]. However, there is only one example of an active W-substituted nitrogenase [206].…”

Section: Tungsten-substituted Molybdoenzymesmentioning

confidence: 99%

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Tungsten in biological systems

Kletzin

Adams

1996

FEMS Microbiology Reviews

134

144

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Tungsten (atomic number 74) and the chemically analogous and very similar metal molybdenum (atomic number 42) are minor yet equally abundant elements on this planet. The essential role of molybdenum in biology has been known for decades and molybdoenzymes are ubiquitous. Yet, it is only recently that a biological role for tungsten has been established in prokaryotes, although not as yet in eukaryotes. The best characterized organisms with regard to their metabolism of tungsten are certain species of hyperthermophilic archaea (Pyrococcus furiosus and Thermococcus litoralis), methanogens (Methanobacterium thermoautotrophicum and Mb. wolfei), Gram-positive bacteria (Clostridium thermoaceticum, C. formicoaceticum and Eubacterium acidaminophilum), Gram-negative anaerobes (Desulfovibrio gigas and Pelobacter acetylenicus) and Gram-negative aerobes (Methylobacterium sp. RXM). Of these, only the hyperthermophilic archaea appear to be obligately tungsten-dependent. Four different types of tungstoenzyme have been purified: formate dehydrogenase, formyl methanofuran dehydrogenase, acetylene hydratase, and a class of phylogenetically related oxidoreductases that catalyze the reversible oxidation of aldehydes. These are carboxylic reductase, and three ferredoxin-dependent oxidoreductases which oxidize various aldehydes, formaldehyde and glyceraldehyde 3-phosphate. All tungstoenzymes catalyze redox reactions of very low potential (< -420 mV) except one (acetylene hydratase) which catalyzes a hydration reaction. The tungsten in these enzymes is bound by a pterin moiety similar to that found in molybdoenzymes. The first crystal structure of a tungsten-or pterin-containing enzyme, that of aldehyde ferredoxin oxidoreductase from P. furiosus, has revealed a catalytic site with one W atom coordinated to two pterin molecules which are themselves bridged by a magnesium ion. The geochemical, ecological, biochemical and phylogenetic basis for W-vs. Mo-dependent organisms is discussed.

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“…There are many reports that molybdate requirement for the growth of N2-fixing bacteria can be replaced with tungstate or vanadate, though nitrogenase activity is lower compared with that in the cell grown normally in the presence of molybdate (26)(27)(28). Substitution of tungsten for molybdenum in nitrate reductase from different sources always led to inactive enzymes (29,30).…”

Section: Discussionmentioning

confidence: 99%

Promoting Effect of Molybdate on the Growth of a Sulfur-Oxidizing Bacterium, Thiobacillus Thiooxidans

Takakuwa

Nishiwaki²,

Hosoda

et al. 1977

J. Gen. Appl. Microbiol.

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In order to analyze the growth of Thiobacillus thiooxidans in the basal Starkey's medium supplemented with solid particles of sulfur, CS, method was developed to measure the cells adhering to the sulfur particles; the cells were totally released from the sulfur particles into the liquid phase by shaking of the culture with carbon disulfide, so that the total amount of cells existing in the culture could be measured quantitatively. The growth of Thiobacillus thiooxidans was remarkably enhanced by the addition of a trace amount of heavy metal ions to the basal Starkey's medium. It was found that, at the initial phase of growth, practically all the cells were attached on the surface of sulfur particles and, with progress of the culture, an increasing number of cells appeared in the liquid phase. At the stationary phase of growth, about equal amounts of cells were distributed on the sulfur particles and in the liquid phase.Among the trace elements added, molybdate was found to be the very substance to accelerate the growth of Thiobacillus thiooxidans. In the presence of molybdate (below 0.3 ppm as molybdenum) the specific growth rate and the final cell yield increased 2-and 4-fold, respectively, compared to those in its absence. This stimulative effect could not be substituted by tungstate, chromate, or vanadate.The growth physiology of the sulfur-oxidizing bacterium, Thiobacillus thiooxidans, which was first discovered by NATHANSOHN (1) and isolated by WAKSMAN and JOFFE (2), has been the subject of repeated studies in the past (3-10). A salient feature of this bacterium is that it thrives chemoautotrophically by oxidizing elementary sulfur to sulfuric acid, and it has been observed (4,11) that during the

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A changed nitrogenase activity in Rhodospirillum rubrum after substitution of tungsten for molybdenum

Cited by 17 publications

References 15 publications

Purification and characterization of the alternative nitrogenase from the photosynthetic bacterium Rhodospirillum rubrum

Purification and characterization of the alternative nitrogenase from the photosynthetic bacterium Rhodospirillum rubrum

Tungsten in biological systems

Promoting Effect of Molybdate on the Growth of a Sulfur-Oxidizing Bacterium, Thiobacillus Thiooxidans

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