The Bidirectional NiFe-hydrogenase in Synechocystis sp. PCC 6803 Is Reduced by Flavodoxin and Ferredoxin and Is Essential under Mixotrophic, Nitrate-limiting Conditions

Gutekunst, Kirstin; Chen, Xi; Schreiber, Karoline; Kaspar, Ursula; Makam, Srinivas N.; Appel, Jens

doi:10.1074/jbc.m113.526376

Cited by 116 publications

(137 citation statements)

References 53 publications

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“…This is consistent with the strong upregulation (top 2% to 12% of most-changing transcripts observed) in the dark of the hox genes (hoxE, hoxF, hoxU, hoxY, and hoxH, which are sll1220, sll1221, sll1223, sll1224, and sll1226) that encode the bidirectional NiFe-hydrogenase, as well as hydrogenase maturation gene hypA1 (slr1675, top 1% of changing transcripts) (see also Table S4 in the supplemental material). Interestingly, the largest overall fold change was observed for sll0741, encoding the pyruvate flavodoxin/ferredoxin oxidoreductase, which was recently shown to be the electron source of the hydrogenase (37). However, protein levels of ferredoxin-nitrite reductase remained stable, whereas ferredoxin-nitrate reductase was not detected (see Table S1).…”

Section: Resultsmentioning

confidence: 90%

Culturing Synechocystis sp. Strain PCC 6803 with N ₂ and CO ₂ in a Diel Regime Reveals Multiphase Glycogen Dynamics with Low Maintenance Costs

Angermayr

Alphen

Hasdemir

et al. 2016

Appl Environ Microbiol

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Investigating the physiology of cyanobacteria cultured under a diel light regime is relevant for a better understanding of the resulting growth characteristics and for specific biotechnological applications that are foreseen for these photosynthetic organisms. Here, we present the results of a multiomics study of the model cyanobacterium Synechocystis sp. strain PCC 6803, cultured in a lab-scale photobioreactor in physiological conditions relevant for large-scale culturing. The culture was sparged with N 2 and CO 2 , leading to an anoxic environment during the dark period. Growth followed the availability of light. Metabolite analysis performed with 1 H nuclear magnetic resonance analysis showed that amino acids involved in nitrogen and sulfur assimilation showed elevated levels in the light. Most protein levels, analyzed through mass spectrometry, remained rather stable. However, several high-light-response proteins and stress-response proteins showed distinct changes at the onset of the light period. Microarray-based transcript analysis found common patterns of ϳ56% of the transcriptome following the diel regime. These oscillating transcripts could be grouped coarsely into genes that were upregulated and downregulated in the dark period. The accumulated glycogen was degraded in the anaerobic environment in the dark. A small part was degraded gradually, reflecting basic maintenance requirements of the cells in darkness. Surprisingly, the largest part was degraded rapidly in a short time span at the end of the dark period. This degradation could allow rapid formation of metabolic intermediates at the end of the dark period, preparing the cells for the resumption of growth at the start of the light period. IMPORTANCEIndustrial-scale biotechnological applications are anticipated for cyanobacteria. We simulated large-scale high-cell-density culturing of Synechocystis sp. PCC 6803 under a diel light regime in a lab-scale photobioreactor. In BG-11 medium, Synechocystis grew only in the light. Metabolite analysis grouped the collected samples according to the light and dark conditions. Proteome analysis suggested that the majority of enzyme-activity regulation was not hierarchical but rather occurred through enzyme activity regulation. An abrupt light-on condition induced high-light-stress proteins. Transcript analysis showed distinct patterns for the light and dark periods. Glycogen gradually accumulated in the light and was rapidly consumed in the last quarter of the dark period. This suggests that the circadian clock primed the cellular machinery for immediate resumption of growth in the light. Understanding cyanobacterial physiology in a diel environment is of interest to understand circadian regulation in general and for the utilization of these organisms in biotechnological applications. Our exploration of the effect of a diel light cycle on a cyanobacterial culture started with the wish to investigate the response of the metabolic network of the cells to the imposed repetitively fluctuating environment,...

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Section: Resultsmentioning

confidence: 90%

Culturing Synechocystis sp. Strain PCC 6803 with N ₂ and CO ₂ in a Diel Regime Reveals Multiphase Glycogen Dynamics with Low Maintenance Costs

Angermayr

Alphen

Hasdemir

et al. 2016

Appl Environ Microbiol

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“…In the cyanobacterium Synechocystis spp. PCC 6803 it was shown that the bidirectional hydrogenase could also directly accept electrons from Fd or flavodoxin, which explains the production of H 2 by overreduction of the Fd pool in the light or fermentative metabolism under anoxic dark conditions [91].…”

Section: Group 3d This Subgroup Consists Of Bidirectional Heteromultmentioning

confidence: 99%

[FeFe]- and [NiFe]-hydrogenase diversity, mechanism, and maturation

Peters

Schut

Boyd

et al. 2015

Biochimica et Biophysica Acta (BBA) - Molecular Cell Research

411

397

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The [FeFe]- and [NiFe]-hydrogenases catalyze the formal interconversion between hydrogen and protons and electrons, possess characteristic non-protein ligands at their catalytic sites and thus share common mechanistic features. Despite the similarities between these two types of hydrogenases, they clearly have distinct evolutionary origins and likely emerged from different selective pressures. [FeFe]-hydrogenases are widely distributed in fermentative anaerobic microorganisms and likely evolved under selective pressure to couple hydrogen production to the recycling of electron carriers that accumulate during anaerobic metabolism. In contrast, many [NiFe]-hydrogenases catalyze hydrogen oxidation as part of energy metabolism and were likely key enzymes in early life and arguably represent the predecessors of modern respiratory metabolism. Although the reversible combination of protons and electrons to generate hydrogen gas is the simplest of chemical reactions, the [FeFe]- and [NiFe]-hydrogenases have distinct mechanisms and differ in the fundamental chemistry associated with proton transfer and control of electron flow that also help to define catalytic bias. A unifying feature of these enzymes is that hydrogen activation itself has been restricted to one solution involving diatomic ligands (carbon monoxide and cyanide) bound to an Fe ion. On the other hand, and quite remarkably, the biosynthetic mechanisms to produce these ligands are exclusive to each type of enzyme. Furthermore, these mechanisms represent two independent solutions to the formation of complex bioinorganic active sites for catalyzing the simplest of chemical reactions, reversible hydrogen oxidation. As such, the [FeFe]- and [NiFe]-hydrogenases are arguably the most profound case of convergent evolution. This article is part of a Special Issue entitled: Fe/S proteins: Analysis, structure, function, biogenesis and diseases.

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“…Cyanobacterial hydrogenases, thus, are linked to both photosynthetic and respiratory electron transport chains (Cournac et al 2004;Schmitz and Bothe 1996;Appel and Schulz 1996). Moreover, recent evident suggests that both ferredoxins and flavodoxins could act as electron donors to the cyanobacterial hydrogenase (Gutekunst et al 2014). Besides the major enzymatic differences between [FeFe] and [NiFe]-enzymes described above, it must be noted that [NiFe]-hydrogenases are constitutively expressed, while the expression of [FeFe]-hydrogenases requires anaerobic induction.…”

Section: Hydrogenasesmentioning

confidence: 96%

Implementation of photobiological H2 production: the O2 sensitivity of hydrogenases

Ghirardi

2015

Photosynth Res

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The search for the ultimate carbon-free fuel has intensified in recent years, with a major focus on photoproduction of H2. Biological sources of H2 include oxygenic photosynthetic green algae and cyanobacteria, both of which contain hydrogenase enzymes. Although algal and cyanobacterial hydrogenases perform the same enzymatic reaction through metallo-clusters, their hydrogenases have evolved separately, are expressed differently (transcription of algal hydrogenases is anaerobically induced, while bacterial hydrogenases are constitutively expressed), and display different sensitivity to O2 inactivation. Among various physiological factors, the sensitivity of hydrogenases to O2 has been one of the major factors preventing implementation of biological systems for commercial production of renewable H2. This review addresses recent strategies aimed at engineering increased O2 tolerance into hydrogenases (as of now mainly unsuccessful), as well as towards the development of methods to bypass the O2 sensitivity of hydrogenases (successful but still yielding low solar conversion efficiencies). The author concludes with a description of current approaches from various laboratories to incorporate multiple genetic traits into either algae or cyanobacteria to jointly address limiting factors other than the hydrogenase O2 sensitivity and achieve more sustained H2 photoproduction activity.

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The Bidirectional NiFe-hydrogenase in Synechocystis sp. PCC 6803 Is Reduced by Flavodoxin and Ferredoxin and Is Essential under Mixotrophic, Nitrate-limiting Conditions

Cited by 116 publications

References 53 publications

Culturing Synechocystis sp. Strain PCC 6803 with N ₂ and CO ₂ in a Diel Regime Reveals Multiphase Glycogen Dynamics with Low Maintenance Costs

Culturing Synechocystis sp. Strain PCC 6803 with N ₂ and CO ₂ in a Diel Regime Reveals Multiphase Glycogen Dynamics with Low Maintenance Costs

[FeFe]- and [NiFe]-hydrogenase diversity, mechanism, and maturation

Implementation of photobiological H2 production: the O2 sensitivity of hydrogenases

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The Bidirectional NiFe-hydrogenase in Synechocystis sp. PCC 6803 Is Reduced by Flavodoxin and Ferredoxin and Is Essential under Mixotrophic, Nitrate-limiting Conditions

Cited by 116 publications

References 53 publications

Culturing Synechocystis sp. Strain PCC 6803 with N 2 and CO 2 in a Diel Regime Reveals Multiphase Glycogen Dynamics with Low Maintenance Costs

Culturing Synechocystis sp. Strain PCC 6803 with N 2 and CO 2 in a Diel Regime Reveals Multiphase Glycogen Dynamics with Low Maintenance Costs

[FeFe]- and [NiFe]-hydrogenase diversity, mechanism, and maturation

Implementation of photobiological H2 production: the O2 sensitivity of hydrogenases

Contact Info

Product

Resources

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Culturing Synechocystis sp. Strain PCC 6803 with N ₂ and CO ₂ in a Diel Regime Reveals Multiphase Glycogen Dynamics with Low Maintenance Costs

Culturing Synechocystis sp. Strain PCC 6803 with N ₂ and CO ₂ in a Diel Regime Reveals Multiphase Glycogen Dynamics with Low Maintenance Costs