Two biochemically distinct classes of fumarase in Escherichia coli

Woods, Sally A.; Schwartzbach, Steven D.; Guest, John R.

doi:10.1016/0167-4838(88)90050-7

Cited by 183 publications

(174 citation statements)

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“…Two of these,fumA andfumC, are at 35.5 min on the E. coli map (22,23) and the third,fumB, is at 93.5 min (23). Fumarases A and B are dimeric labile iron-sulfur proteins, whereas fumarase C is a tetrameric stable enzyme that has homology to aspartase and to argininosuccinase (24) and that does not contain an Abbreviations: SOD, superoxide dismutase; G6PD, glucose-6-phosphate dehydrogenase. *On leave from the Institute of Physiology, Bulgarian Academy of Sciences, Acad.…”

Section: Resultsmentioning

confidence: 99%

Fumarase C, the stable fumarase of Escherichia coli, is controlled by the soxRS regulon.

Liochev

Fridovich

1992

Proc. Natl. Acad. Sci. U.S.A.

223

173

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Fumarase C was strongly induced by paraquat in a parental strain of Escherichia coli but was not induced in a strain lacking the soxRS response. Moreover, a strain that constitutively expresses the soxRS regulon contained more fumarase C than did the parental strain. The Mn-containing superoxide dismutase and glucose-6-phosphate dehydrogenase, members of the soxRS regulon, were similarly induced by paraquat. Mutational defects in glucose-6-phosphate dehydrogenase increased the induction of fumarase C by paraquat. For Mn-containing superoxide dismutase, responsiveness to paraquat was also enhanced in the glucose-6-phosphate dehydrogenase-defective strains. Overproduction of the Mn-containing superoxide dismutase, elicited by isopropyl beta-D-thiogalactoside in a tac-sodA fusion strain, did not diminish induction of fumarase C or of glucose-6-phosphate dehydrogenase by paraquat, and induction of these enzymes was more sensitive to paraquat when the cells were growing on succinate rather than on LB medium. These results indicate that fumarase C is a member of the soxRS regulon and that this regulon does not respond to changes in O2- concentration but perhaps does respond to some consequence of a decrease in the ratio of NADPH to NADP+.

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Section: Resultsmentioning

confidence: 99%

Fumarase C, the stable fumarase of Escherichia coli, is controlled by the soxRS regulon.

Liochev

Fridovich

1992

Proc. Natl. Acad. Sci. U.S.A.

223

173

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“…Fumarate Hydratase (FH) FH converts fumarate to malate and exists in nature in two forms: class I, as found in Apicomplexa, which contains a required Fe-S cluster [45], and the Fe-S cluster-free class II, as found in mammals [58,59]. Apicomplexan FH can contribute to either (mitochondrial) TCA metabolism or (cytosolic) purine salvage, depending on its localization.…”

Section: Mitochondrial Metabolism Across the Alveolatamentioning

confidence: 99%

Apicomplexan Energy Metabolism: Carbon Source Promiscuity and the Quiescence Hyperbole

Jacot

Waller

Soldati‐Favre

et al. 2016

Trends in Parasitology

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Pages 15apicomplexan mitochondrion in energy generation has remained unclear, given the glucosereplete intracellular nature of the environmental niches of these parasites and the apparent reduction of mitochondrial metabolic pathways [4][5][6][7]. For example, apicomplexan mitochondria lack 'type I' NADH dehydrogenase (NDH, complex I of the ETC) and many apparently lack the enzymes and transporters required for fatty acid b-oxidation [8,9]. Furthermore, the pyruvate dehydrogenase complex (PDH) responsible for conversion of pyruvate into acetyl-CoA -an obligate fuel for the TCA cycle -is only present in the apicoplast [10]. Consequently, there was no obvious entry point to allow catalysis of glycolytic pyruvate by the TCA cycle [10][11][12][13][14]. Despite this, there is overwhelming evidence that apicomplexans rely on a functional and canonical TCA cycle (as reviewed [4,5,15]), and apicomplexan genome annotations indicate the presence of all enzymes of the TCA cycle. Only one clade of apicomplexans, Cryptosporidium spp., show evidence of outright loss of the TCA cycle, but these taxa retain only a highly reduced mitochondrion, the mitosome, and have also lost their apicoplast [5,8,16].This review highlights how metabolomics technologies coupled to genetic manipulation have helped in unraveling apicomplexan parasite plasticity in carbon source utilization through different life stages, revealing a complex and sometimes counter-intuitive pattern of metabolic gains, losses, and reassignments. These changes have presumably been tailored to allow these parasites to thrive within their various host niches, but may constitute some much-needed Achilles' heels in the fight against these devastating diseases. Plasmodium falciparum and the Glycolytic DeceitGlycolysis has long appeared to be the main source of ATP and NAD(P)H in the erythrocytic stages of the malaria parasites, [5,[17][18][19][20][21]. Indeed, glucose uptake in P. falciparum-infected red blood cells (RBCs) has been observed to increase 75-100-fold compared to uninfected RBC [22][23][24][25]. Up to 93% of glucose is converted directly to lactate in asexual stages [26][ 4 _ T D $ D I F F ] and is ultimately excreted into the surrounding host cell. Perturbation of glucose uptake is detrimental to parasite growth [27,28], suggesting that glycolysis is an important part of the parasite's strategy for rapid proliferation. In a manner analogous to the Warburg effect observed in highly-proliferative cancer lines and other rapidly-growing cells (e.g., yeast and bloodstream Trypanosoma spp.), Plasmodium (in erythrocytic stages) has opted for fast generation of ATP through substrate-level phosphorylation and secretion of lactate as an end-product (aerobic fermentative glycolysis), as opposed to the 'slow but efficient' mitochondrial oxidative phosphorylation and complete oxidation [29]. Reasons for this dependence on glycolytic fermentation remain unclear -after all, blood stages of Plasmodium certainly have access to oxygen -but it may be a way of avoiding excessiv...

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“…coli has three genes that encode fumarate hydratase; fumA and fumB of the class I type and fumC of the class II type. fumA and fumC genes are in tandem and are driven by a common promoter (7,29). Starting with JW4083-1, a ∆fumB strain of E. coli, a triple knockout ΔfumACB strain, in which all the three major fum …”

Section: Pffh Complements Fumarase Deficiency In E Coli-mentioning

confidence: 99%

Biochemical characterization and essentiality of fumarate hydratase

Jayaraman¹,

Suryavanshi²,

Kalale

et al. 2018

Journal of Biological Chemistry

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Plasmodium falciparum (Pf), the causative agent of malaria, has an iron-sulfur cluster-containing class I fumarate hydratase (FH) that catalyzes the interconversion of fumarate to malate, a wellknown reaction in the tricarboxylic acid cycle. In humans, the same reaction is catalyzed by class II FH that has no sequence or structural homology with the class I enzyme from Plasmodium. Fumarate is generated in large quantities in the parasite as a byproduct of AMP synthesis and is converted to malate by FH and then used in the generation of the key metabolites oxaloacetate, aspartate, and pyruvate. Previous studies have identified the FH reaction as being essential to P. falciparum, but biochemical characterizations of PfFH that may provide leads for the development of specific inhibitors are lacking. Here, we report on the kinetic characterization of purified recombinant PfFH, functional complementation of fh deficiency in Escherichia coli, and mitochondrial localization in the parasite. We found that the substrate analog mercaptosuccinic acid is a potent PfFH inhibitor, with a K i value in the nanomolar range. The fh gene could not be knocked out in Plasmodium berghei when transfectants were introduced into BALB/c mice; however, fh knockout was successful when C57BL/6 mice were used as host, suggesting that the essentiality of the fh gene to the parasite was mouse strain dependent.Plasmodium falciparum (Pf), the causative agent of the most lethal form of malaria, during its intra-erythrocytic asexual stages, derives ATP primarily from glycolysis with low contribution from mitochondrial pathways (1, 2). The bulk of pyruvate formed is converted to lactic acid with a minor amount entering the tricarboxylic acid (TCA) cycle, the flux through which is upregulated in sexual stages (2). Key intermediates that anaplerotically feed into the TCA cycle are α-ketoglutarate derived from glutamate, oxaloacetate (OAA) from phosphoenolpyruvate, and fumarate from adenosine 5΄-monophosphate (AMP) synthesis. Synthesis of AMP in the parasite is solely from inosine-5΄-monophosphate (IMP) through a pathway involving the enzymes adenylosuccinate synthetase (ADSS) and adenylosuccinate lyase (ASL). The net reaction of ADSS and ASL involves consumption of GTP and aspartate and, generation of GDP, P i and fumarate. In the rapidly dividing parasite with an AT-rich genome and high energy requirements, leading to a high demand for adenine pools, one would expect a high flux of fumarate generation. The parasite does not secrete fumarate but instead, the carbon derived from this metabolite can be traced in malate, OAA, aspartate, pyruvate (through PEP) and lactate (3). The metabolic significance of this fumarate anaplerosis is still obscure. In this context, fumarate hydratase (FH, fumarase) the key enzyme to metabolize fumarate becomes an Fumarate hydratase (fumarase, E.C. 4.2.1.2) catalyzes the reversible conversion of fumarate to malate. The stereospecific reaction involves the anti-addition of a water molecule across the carbon-carbon...

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Two biochemically distinct classes of fumarase in Escherichia coli

Cited by 183 publications

References 36 publications

Fumarase C, the stable fumarase of Escherichia coli, is controlled by the soxRS regulon.

Fumarase C, the stable fumarase of Escherichia coli, is controlled by the soxRS regulon.

Apicomplexan Energy Metabolism: Carbon Source Promiscuity and the Quiescence Hyperbole

Biochemical characterization and essentiality of fumarate hydratase

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