GLUTAMINE SYNTHETASE AND NITROGENASE ACTIVITY IN THE BLUE‐GREEN ALGA <i>ANABAENA CYLINDRICA</i>

Rowell, P.; Enticott, S.; Stewart, W. D. P.

doi:10.1111/j.1469-8137.1977.tb02179.x

Cited by 112 publications

(56 citation statements)

References 31 publications

(28 reference statements)

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“…In Anabaena variabilis, high-and low-affinity systems for the transport of Gln and Glu (4) as well as a system taking up Leu (29) have been reported. High-affinity transport of Gln has also been detected in Anabaena cylindrica (24), and a Glu/Asp transport system has been detected in a Nostoc sp. (28).…”

mentioning

confidence: 94%

Amino acid transport systems required for diazotrophic growth in the cyanobacterium Anabaena sp. strain PCC 7120

1995

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Uptake of 16 amino acids by the filamentous, heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120 was characterized with regard to kinetic parameters of transport, intracellular accumulation of the transported amino acids, and sensitivity of the transport process to energy metabolism inhibitors. Mutants resistant to certain toxic analogs of some amino acids were isolated that were impaired in amino acid transport. Results obtained in this study, together with those reported previously (A. Herrero and E. Flores, J. Biol. Chem. 265:3931-3935, 1990), suggest that there are at least five amino acid transport systems in strain PCC 7120: one high-affinity, active system for basic amino acids; one low-affinity, passive system for basic amino acids; two high-affinity, active systems with overlapping, but not identical, specificities for neutral amino acids; and one putative system for acidic amino acids. Some of the amino acid transport mutants were impaired in diazotrophic growth. These mutants were unable to develop a normal percentage of heterocysts and normal nitrogenase activity in response to nitrogen stepdown. Putative roles for the amino acid transport systems in uptake of extracellular amino acids, recapture of amino acids that have leaked from the cells, and intercellular transfer of amino acids in the filaments of Anabaena sp. strain PCC 7120 are discussed.

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confidence: 94%

Amino acid transport systems required for diazotrophic growth in the cyanobacterium Anabaena sp. strain PCC 7120

1995

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“…2) It is worth noting that all the kinetic values for biosynthetic activity were determined by measuring the amount of glutamine formed, as previously described (10), instead of measuring the amount of Pi released or using a coupling system, which could distort the results (2, 12). For cyanobacteria, it has been proposed that intracellular levels of different metabolites, such as amino acids, nucleotides, and divalent cations, are involved in controlling GS activity in vivo (12,16,21,23). The biosynthetic activity of the Synechocystis GS was inhibited by alanine and aspartic acid (52 and 41%, respectively, at a concentration of 1 mM).…”

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confidence: 98%

Purification and properties of glutamine synthetases from the cyanobacteria Synechocystis sp. strain PCC 6803 and Calothrix sp. strain PCC 7601

et al. 1990

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Glutanine synthetases (GSs) from two cyanobacteria, one uniellular (Synechocystis sp. strain PCC 6803) and the other flamentous (Calothrir sp. strain PCC 7601 [FremyeUla diplosiphon]), were purified to homogeneity. The biosynthetic activities of both enzymes were strongly inhibited by ADP, icti that the energy charge of the cell might regulate the GS activity. Both cyanobacteria exhibited an amonum-mediated repression of GS synthesis. In addition, the Synechocystis sp. showed an inactivation of GS promoted by ammonium that had not been demonstrated previously in cyanobacteria.Ammonium assimilation takes place in cyanobacteria mainly by the sequential action of glutamine synthetase (GS) (L-glutamate:ammonia ligase [ADP-forming], EC 6.3.1.2) and glutamate synthase (L-glutamate:ferredoxin oxidoreductase [transaminating], EC 1.4.7

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“…The properties and regulation of the purified glutamine synthetase of N,-fixing cyanobacteria have not so far been reported in detail, but no evidence of regulation by an adenylylation-deadenylylation mechanism was obtained from studies using crude extracts and partially purified preparations (Dharmawardene et al, 1973 ;Rowell et al, 1977;Sawhney & Nicholas, 1978). However, such a regulatory mechanism has been noted in most other N,-fixing prokaryotes so far studied, including various free-living heterotrophic bacteria (Tronick et al, 1973), Rhizobium (Rao et al, 1978) and photosynthetic bacteria (Johansson & Gest, 1977).…”

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confidence: 99%

“…Previously, we have provided evidence based on enzyme studies (Dharmawardene et al, 1973;Rowell et al, 1977), the use of analogues (Stewart & Rowell, 1975;Ladha et al, 1978) and I5N tracer studies that glutamine synthetase is a major enzyne involved in NH4+ assimilation in N,-fixing cyanobacteria. This conclusion is also supported by other work (Wolk et al, 1976;Meeks et al, 1977;Ownby, 1977;Thomas et al, 1977) and there is now substantial evidence that the glutamine synthetase/glutamate synthase pathway (see, for example, Brown et al, 1974) is the primary route of NH4+ assimilation in N,-fixing cyanobacteria.…”

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confidence: 99%

Purification and some Properties of Glutamine Synthetase from the Nitrogen-fixing Cyanobacteria Anabaena cylindrica and a Nostoc sp.

Sampaio

Rowell

Stewart

1979

Journal of General Microbiology

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134

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Glutamine synthetase has been purified to homogeneity from two N,-fixing cyanobacteria, Anabaena cylindrica and a species of Nostoc (the phycobiont of Peltigera canina). The activities of the A . cylindrica enzyme in the biosynthetic and transferase assays were, respectively, 9-4 and 32 pmol product formed min-l (mg protein)-l; the corresponding values for the Nostoc sp. enzyme were 6.5 and 20. Stabilization of the enzyme required Mg2+, glutamate, EDTA and a thiol reagent to be present during purification.The molecular weight of the A. cylindrica enzyme was 59 1000 as estimated by sedimentation analysis, 660000 by gel filtration and 565000 by polyacrylamide gel electrophoresis; the Nostoc sp. enzyme gave values of 630000 by gel filtration and 575000 by electrophoresis. The molecular weights of the sub-units of each enzyme were approximately 49000 to 50 000. Electron microscopy revealed that each molecule was composed of 12 sub-units arranged in two superimposed hexagonal rings. The maximum diameter of the rings was 13-6 nm and the distance between the centres of adjacent sub-units was 4.9 nm.When dialysed in the absence of stabilizing ligands the A . cylindrica enzyme lost activity and the protein band characteristic of the native enzyme was replaced by three bands with approximate molecular weights of 510000, 310000 and 130000. These sub-species reassociated and activity was restored by adding 2-mercaptoethanol and substrates. A similar reversible deactivation has been observed with glutamine synthetase from photosynthetic eukaryotes and yeast but no similar data have been reported for a N,-fixing prokaryote.

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GLUTAMINE SYNTHETASE AND NITROGENASE ACTIVITY IN THE BLUE‐GREEN ALGA ANABAENA CYLINDRICA

Cited by 112 publications

References 31 publications

Amino acid transport systems required for diazotrophic growth in the cyanobacterium Anabaena sp. strain PCC 7120

Amino acid transport systems required for diazotrophic growth in the cyanobacterium Anabaena sp. strain PCC 7120

Purification and properties of glutamine synthetases from the cyanobacteria Synechocystis sp. strain PCC 6803 and Calothrix sp. strain PCC 7601

Purification and some Properties of Glutamine Synthetase from the Nitrogen-fixing Cyanobacteria Anabaena cylindrica and a Nostoc sp.

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