Regulation of nitrogenase activity in<i>Anabaena variabilis</i>by modification of the Fe protein

Reich, Sabine; Böger, Peter

doi:10.1111/j.1574-6968.1989.tb03022.x

Cited by 44 publications

(4 citation statements)

References 25 publications

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“…The reduction in NA was correlated with a change of the apparent molecular mass (to an approximately equal distribution of higherand lower-molecular-mass forms) of the Fe protein (Fig. 7), which is similar to the response of the Fe protein in R. rubrum and A. vaniabilis (20,32). Incubation under N2 resulted in conversion of the Fe protein to the lower-molecular-mass form (Fig.…”

Section: Fig 8 Effect Of Incubation Under N2 or 02 On Abundance Of Thesupporting

confidence: 61%

“…A characteristic of nitrogenase in some heterocystous and nonheterocystous cyanobacteria is a change in the apparent molecular mass of the Fe protein under certain conditions that appears to be correlated with activity (6,26,32,38). In addition, there were initially suggestions of a conformational protection of nitrogenase in response to elevated oxygen in the nonheterocystous cyanobacterium Oscillatoria limosa (39), which may be related to the recently described change in molecular mass of the Fe protein in this species (12,38).…”

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confidence: 91%

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Modification of the Fe Protein of Nitrogenase in Natural Populations of Trichodesmium thiebautii

Zehr

Wyman

Miller

et al. 1993

Appl Environ Microbiol

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The Fe protein of nitrogenase in the marine nonheterocystous cyanobacterium Trichodesmium thiebautii is interconverted between two forms, which is reminiscent of the ADP-ribosylation described in the purple bacterium Rhidospirillum rubrum. In natural populations of T. thiebautii during the day, when nitrogenase activity (NA) is present and while photosynthetic rates are high, a low-molecular-mass form of the Fe protein is present. In the late afternoon, the low-molecular-mass form is partially converted to a higher-molecular-mass form (approximately equal distribution of highand low-molecular-mass forms of the Fe protein subunits), concurrent with cessation of NA. Some of the higher-molecular-mass form persists through the night until the very early morning, when the lower-molecular-mass form appears. New synthesis of both the Fe and MoFe proteins of nitrogenase appears to occur at this time. The higher-molecular-mass form of the Fe protein is also produced rapidly in response to artificially elevated external 02 levels (40%) during the day. T. thiebautii is capable of recovery of NA in less than 1 h following exposure to 40% 02, which is correlated with the return of the Fe protein to the lower-molecular-mass form. Recovery from exposure to 02 is not dependent upon protein synthesis. The modification of the Fe protein is clearly involved in regulation of NA during the diel cycle of NA in T. thiebautii but may also be involved in protecting the Fe protein during transient 02 concentration increases.

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Section: Fig 8 Effect Of Incubation Under N2 or 02 On Abundance Of Thesupporting

confidence: 61%

mentioning

confidence: 91%

Modification of the Fe Protein of Nitrogenase in Natural Populations of Trichodesmium thiebautii

Zehr

Wyman

Miller

et al. 1993

Appl Environ Microbiol

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“…Once separated, the proteins were transferred by electrophoresis to a nitrocellulose filter (BA85 from Schleicher & Schuell, Keene, N.H., or Immobilon NC from Millipore Corp., Bedford, Mass.) and incubated with a polyclonal antibody (diluted 1:7,000) raised against the Feprotein of nitrogenase from Anabaena variabifis ATCC 29413 (35). The antigen-antibody product was visualized with an alkaline phosphatase conjugate to anti-rabbit immunoglobulin G (Promega, Madison, Wisc.)…”

Section: Materias and Methodsmentioning

confidence: 99%

Synthesis of nitrogenase in mutants of the cyanobacterium Anabaena sp. strain PCC 7120 affected in heterocyst development or metabolism

et al. 1992

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Mutants of Anabaena sp. strain PCC 7120 that are incapable of sustained growth with air as the sole source of nitrogen were generated by using Tn5-derived transposons. Nitrogenase was expressed only in mutants that showed obvious morphological signs of heterocyst differentiation. Even under rigorously anaerobic conditions, nitrogenase was not synthesized in filaments that were unable to develop heterocysts. These results suggest that competence to synthesize nitrogenase requires a process that leads to an early stage of visible heterocyst development and are consistent with the idea that synthesis of nitrogenase is under developmental control (J. Elhai and C. P. Wolk, EMBO J. 9:3379-3388, 1990). We isolated mutants in which differentiation was arrested at an intermediate stage of heterocyst formation, suggesting that differentiation proceeds in stages; those mutants, as well as mutants with aberrant heterocyst envelopes and a mutant with defective respiration, expressed active nitrogenase under anaerobic conditions only. These results support the idea that the heterocyst envelope and heterocyst respiration are required for protection of nitrogenase from inactivation by oxygen. In the presence of air, such mutants contained less nitrogenase than under anaerobic conditions, and the Fe-protein was present in a posttranslationally modified inactive form. We conclude that internal partial oxygen pressure sufficient to inactivate nitrogenase is insufficient to repress synthesis of the enzyme completely. Among mutants with an apparently intact heterocyst envelope and normal respiration, three had virtually undetectable levels of dinitrogenase reductase under all conditions employed. However, three others expressed oxygen-sensitive nitrogenase activity, suggesting that respiration and barrier to diffusion of gases may not suffice for oxygen protection of nitrogenase in these mutants; two of these mutants reduced acetylene to ethylene and ethane.

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“…These treatments cause inactivation of the enzyme, correlated with a decrease of electrophoretic mobility of dinitrogenase reductase. This effect was visualized by immunoblotting using a specific antibody prepared against the Fe-protein of A. vanabilis (25), indicative of a posttranslational enzyme modification.…”

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confidence: 99%

In vitro activation of dinitrogenase reductase from the cyanobacterium Anabaena variabilis (ATCC 29413)

et al. 1992

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Nitrogenase of the heterocystous cyanobacterium Anabaena variabilis was inactivated in vivo (S. Reich, H. Almon, and P. Böger, FEMS Microbiol. Lett. 34:53-56, 1986). Partially purified and modified (inactivated) dinitrogenase reductase (Fe-protein) of such cells was reactivated by isolated membrane fractions of A. variabilis or of Rhodospirillum rubrum, and acetylene reduction was measured. Reactivation requires ATP, Mg2+, and Mn2+. The activating principle is localized in the heterocyst and was found effective only when prepared from cells exhibiting active nitrogenase. It also restores the activity of modified Fe-protein from R. rubrum.

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Regulation of nitrogenase activity inAnabaena variabilisby modification of the Fe protein

Cited by 44 publications

References 25 publications

Modification of the Fe Protein of Nitrogenase in Natural Populations of Trichodesmium thiebautii

Modification of the Fe Protein of Nitrogenase in Natural Populations of Trichodesmium thiebautii

Synthesis of nitrogenase in mutants of the cyanobacterium Anabaena sp. strain PCC 7120 affected in heterocyst development or metabolism

In vitro activation of dinitrogenase reductase from the cyanobacterium Anabaena variabilis (ATCC 29413)

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