Characterization of methylmalonyl-CoA mutase involved in the propionate photoassimilation of Euglena gracilis Z

Miyamoto, Emi; Tanioka, Yuri; Nishizawa‐Yokoi, Ayako; Yabuta, Yukinori; Ohnishi, Kouhei; Misono, Haruo; Shigeoka, Shigeru; Nakano, Yoshiaki; Watanabe, Fumio

doi:10.1007/s00203-010-0572-x

Cited by 15 publications

(21 citation statements)

References 30 publications

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“…Propionyl-CoA is produced via the same short methylmalonyl-CoAdependent route as that found in animal mitochondria (Schneider and Betz 1985), and homologs of the underlying enzymes, methylmalonyl-CoA mutase and propionyl-CoA carboxylase (which provides ATP via substratelevel phosphorylation), are abundantly expressed in euglenoid EST data (Ahmadinejad et al 2007). Methylmalonyl-CoA mutase from Euglena has been characterized (Miyamoto et al 2010); the enzyme is also present in humans, where it is one of our only two vitamin B 12 (cobalamin)-dependent enzymes (Roth et al 1996). Euglena growth was once the standard assay for serum B 12 levels, because of its B 12 -dependent ribonucleotide reductase (Torrents et al 2006).…”

Section: Rhodoquinonementioning

confidence: 98%

The Mitochondrion of Euglena gracilis

Zimorski

Rauch

Hellemond

et al. 2017

Advances in Experimental Medicine and Biology

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In the presence of oxygen, Euglena gracilis mitochondria function much like mammalian mitochondria. Under anaerobiosis, E. gracilis mitochondria perform a malonyl-CoA independent synthesis of fatty acids leading to accumulation of wax esters, which serve as the sink for electrons stemming from glycolytic ATP synthesis and pyruvate oxidation. Some components (enzymes and cofactors) of Euglena's anaerobic energy metabolism are found among the anaerobic mitochondria of invertebrates, others are found among hydrogenosomes, the H-producing anaerobic mitochondria of protists.

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Section: Rhodoquinonementioning

confidence: 98%

The Mitochondrion of Euglena gracilis

Zimorski

Rauch

Hellemond

et al. 2017

Advances in Experimental Medicine and Biology

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“…Euglena L-methylmalonyl-CoA mutase was purified and its cDNA sequence was determined (Miyamoto et al 2010). This enzyme, a homodimeric protein with a molecular mass of 78 kDa, contained one adenosylcobalamin per subunit, and sequence similarity betwee n Euglena and mammalian enzymes was over 65%.…”

Section: Formation Of Propionyl-coa As a Primer For Oddnumbered Fattymentioning

confidence: 99%

Wax Ester Fermentation and Its Application for Biofuel Production

Inui

Ishikawa

Tamoi

2017

Advances in Experimental Medicine and Biology

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In Euglena cells under anaerobic conditions, paramylon, the storage polysaccharide, is promptly degraded and converted to wax esters. The wax esters synthesized are composed of saturated fatty acids and alcohols with chain lengths of 10-18, and the major constituents are myristic acid and myristyl alcohol. Since the anaerobic cells gain ATP through the conversion of paramylon to wax esters, the phenomenon is named "wax ester fermentation". The wax ester fermentation is quite unique in that the end products, i.e. wax esters, have relatively high molecular weights, are insoluble in water, and accumulate in the cells, in contrast to the common fermentation end products such as lactic acid and ethanol.A unique metabolic pathway involved in the wax ester fermentation is the mitochondrial fatty acid synthetic system. In this system, fatty acid are synthesized by the reversal of β-oxidation with an exception that trans-2-enoyl-CoA reductase functions instead of acyl-CoA dehydrogenase. Therefore, acetyl-CoA is directly used as a C donor in this fatty acid synthesis, and the conversion of acetyl-CoA to malonyl-CoA, which requires ATP, is not necessary. Consequently, the mitochondrial fatty acid synthetic system makes possible the net gain of ATP through the synthesis of wax esters from paramylon. In addition, acetyl-CoA is provided in the anaerobic cells from pyruvate by the action of a unique enzyme, oxygen sensitive pyruvate:NADP oxidoreductase, instead of the common pyruvate dehydrogenase multienzyme complex.Wax esters produced by anaerobic Euglena are promising biofuels because myristic acid (C) in contrast to other algal produced fatty acids, such as palmitic acid (C) and stearic acid (C), has a low freezing point making it suitable as a drop-in jet fuel. To improve wax ester production, the molecular mechanisms by which wax ester fermentation is regulated in response to aerobic and anaerobic conditions have been gradually elucidated by identifying individual genes related to the wax ester fermentation metabolic pathway and by comprehensive gene/protein expression analysis. In addition, expression of the cyanobacterial Calvin cycle fructose-1,6-bisphosphatase/sedohepturose-1,7-bisphosphatase, in Euglena provided photosynthesis resulting in increased paramylon accumulation enhancing wax ester production. This chapter will discuss the biochemistry of the wax ester fermentation, recent advances in our understanding of the regulation of the wax ester fermentation and genetic engineering approaches to increase production of wax esters for biofuels.

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“…MCMs from Streptomyces cinnamonensis (11), P. shermanii (37), and Methylobacterium extorquens (48) are heterodimers, based on the presence of 80-kDa (MCM-␣) and 65-kDa (MCM-␤) subunits. All other characterized MCMs (from Pleurochrysis carterae [47], Sinorhizobium meliloti [46], Homo sapiens [20], and Euglena gracilis Z [45]) are homodimers based on the presence of ϳ80-kDa subunits. The M. sedula MCM is heterotetrameric (␣ 2 ␤ 2 ) and, therefore, somewhat different in molecular assembly, especially since the B 12 -binding subunit is ϳ15 kDa.…”

Section: Resultsmentioning

confidence: 99%

Epimerase (Msed_0639) and Mutase (Msed_0638 and Msed_2055) Convert ( S )-Methylmalonyl-Coenzyme A (CoA) to Succinyl-CoA in the Metallosphaera sedula 3-Hydroxypropionate/4-Hydroxybutyrate Cycle

Han

Hawkins

Adams

et al. 2012

Appl Environ Microbiol

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ABSTRACTCrenarchaeotal genomes encode the 3-hydroxypropionate/4-hydroxybutyrate (3-HP/4-HB) cycle for carbon dioxide fixation. Of the 13 enzymes putatively comprising the cycle, several of them, including methylmalonyl-coenzyme A (CoA) epimerase (MCE) and methylmalonyl-CoA mutase (MCM), which convert (S)-methylmalonyl-CoA to succinyl-CoA, have not been confirmed and characterized biochemically. In the genome ofMetallosphaera sedula(optimal temperature [Topt], 73°C), the gene encoding MCE (Msed_0639) is adjacent to that encoding the catalytic subunit of MCM-α (Msed_0638), while the gene for the coenzyme B12-binding subunit of MCM (MCM-β) is located remotely (Msed_2055). The expression of all three genes was significantly upregulated under autotrophic compared to heterotrophic growth conditions, implying a role in CO2fixation. Recombinant forms of MCE and MCM were produced inEscherichia coli; soluble, active MCM was produced only if MCM-α and MCM-β were coexpressed. MCE is a homodimer and MCM is a heterotetramer (α2β2) with specific activities of 218 and 2.2 μmol/min/mg, respectively, at 75°C. The heterotetrameric MCM differs from the homo- or heterodimeric orthologs in other organisms. MCE was activated by divalent cations (Ni2+, Co2+, and Mg2+), and the predicted metal binding/active sites were identified through sequence alignments with less-thermophilic MCEs. The conserved coenzyme B12-binding motif (DXHXXG-SXL-GG) was identified inM. sedulaMCM-β. The two enzymes together catalyzed the two-step conversion of (S)-methylmalonyl-CoA to succinyl-CoA, consistent with their proposed role in the 3-HP/4-HB cycle. Based on the highly conserved occurrence of single copies of MCE and MCM inSulfolobaceaegenomes, theM. sedulaenzymes are likely to be representatives of these enzymes in the 3-HP/4-HB cycle in crenarchaeal thermoacidophiles.

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Characterization of methylmalonyl-CoA mutase involved in the propionate photoassimilation of Euglena gracilis Z

Cited by 15 publications

References 30 publications

The Mitochondrion of Euglena gracilis

The Mitochondrion of Euglena gracilis

Wax Ester Fermentation and Its Application for Biofuel Production

Epimerase (Msed_0639) and Mutase (Msed_0638 and Msed_2055) Convert ( S )-Methylmalonyl-Coenzyme A (CoA) to Succinyl-CoA in the Metallosphaera sedula 3-Hydroxypropionate/4-Hydroxybutyrate Cycle

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