scholarly journals Mercury Methylation Independent of the Acetyl-Coenzyme A Pathway in Sulfate-Reducing Bacteria

2003 ◽  
Vol 69 (9) ◽  
pp. 5414-5422 ◽  
Author(s):  
Eileen B. Ekstrom ◽  
François M. M. Morel ◽  
Janina M. Benoit
Keyword(s):  
Coenzyme A ◽  
Sulfate Reducing Bacteria ◽  
Mercury Methylation ◽  
Acetyl Coa ◽  
Acetyl Coenzyme A ◽  
Sulfate Reducing ◽  
Acetyl Coenzyme ◽  
Acetyl Coa Pathway ◽  
Reducing Bacteria ◽  
Methylmercury Production

ABSTRACT Sulfate-reducing bacteria (SRB) in anoxic waters and sediments are the major producers of methylmercury in aquatic systems. Although a considerable amount of work has addressed the environmental factors that control methylmercury formation and the conditions that control bioavailability of inorganic mercury to SRB, little work has been undertaken analyzing the biochemical mechanism of methylmercury production. The acetyl-coenzyme A (CoA) pathway has been implicated as being key to mercury methylation in one SRB strain, Desulfovibrio desulfuricans LS, but this result has not been extended to other SRB species. To probe whether the acetyl-CoA pathway is the controlling biochemical process for methylmercury production in SRB, five incomplete-oxidizing SRB strains and two Desulfobacter strains that do not use the acetyl-CoA pathway for major carbon metabolism were assayed for methylmercury formation and acetyl-CoA pathway enzyme activities. Three of the SRB strains were also incubated with chloroform to inhibit the acetyl-CoA pathway. So far, all species that have been found to have acetyl-CoA activity are complete oxidizers that require the acetyl-CoA pathway for basic metabolism, as well as methylate mercury. Chloroform inhibits Hg methylation in these species either by blocking the methylating enzyme or by indirect effects on metabolism and growth. However, we have identified four incomplete-oxidizing strains that clearly do not utilize the acetyl-CoA pathway either for metabolism or mercury methylation (as confirmed by the absence of chloroform inhibition). Hg methylation is thus independent of the acetyl-CoA pathway and may not require vitamin B12 in some and perhaps many incomplete-oxidizing SRB strains.

scholarly journals Deconstructing Methanosarcina acetivorans into an acetogenic archaeon

2022 ◽  
Vol 119 (2) ◽  
pp. e2113853119
Author(s):  
Christian Schöne ◽  
Anja Poehlein ◽  
Nico Jehmlich ◽  
Norman Adlung ◽  
Rolf Daniel ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Energy Conservation ◽  
Carbon Fixation ◽  
Coenzyme A ◽  
Methanogenic Archaea ◽  
Methanosarcina Acetivorans ◽  
Acetyl Coa ◽  
Acetyl Coenzyme A ◽  
Acetyl Coenzyme ◽  
Acetyl Coa Pathway

The reductive acetyl-coenzyme A (acetyl-CoA) pathway, whereby carbon dioxide is sequentially reduced to acetyl-CoA via coenzyme-bound C1 intermediates, is the only autotrophic pathway that can at the same time be the means for energy conservation. A conceptually similar metabolism and a key process in the global carbon cycle is methanogenesis, the biogenic formation of methane. All known methanogenic archaea depend on methanogenesis to sustain growth and use the reductive acetyl-CoA pathway for autotrophic carbon fixation. Here, we converted a methanogen into an acetogen and show that Methanosarcina acetivorans can dispense with methanogenesis for energy conservation completely. By targeted disruption of the methanogenic pathway, followed by adaptive evolution, a strain was created that sustained growth via carbon monoxide–dependent acetogenesis. A minute flux (less than 0.2% of the carbon monoxide consumed) through the methane-liberating reaction remained essential, indicating that currently living methanogens utilize metabolites of this reaction also for anabolic purposes. These results suggest that the metabolic flexibility of methanogenic archaea might be much greater than currently known. Also, our ability to deconstruct a methanogen into an acetogen by merely removing cellular functions provides experimental support for the notion that methanogenesis could have evolved from the reductive acetyl-coenzyme A pathway.

scholarly journals Genome Sequence of Serratia marcescens MSU97, a Plant-Associated Bacterium That Makes Multiple Antibiotics

2017 ◽  
Vol 5 (9) ◽  
Author(s):  
Miguel A. Matilla ◽  
Zulema Udaondo ◽  
Tino Krell ◽  
George P. C. Salmond
Keyword(s):  
Serratia Marcescens ◽  
Genome Sequence ◽  
Coenzyme A ◽  
Acetyl Coa Carboxylase ◽  
Acetyl Coa ◽  
Acetyl Coenzyme A ◽  
Content Type ◽  
Acetyl Coenzyme ◽  
Multiple Antibiotics

ABSTRACT Serratia marcescens MSU97 was isolated from the Guayana region of Venezuela due to its ability to suppress plant-pathogenic oomycetes. Here, we report the genome sequence of MSU97, which produces various antibiotics, including the bacterial acetyl-coenzyme A (acetyl-CoA) carboxylase inhibitor andrimid, the chlorinated macrolide oocydin A, and the red linear tripyrrole antibiotic prodigiosin.

scholarly journals Changes of Coenzyme A and Acetyl-Coenzyme A Concentrations in Rats after a Single-Dose Intraperitoneal Injection of Hepatotoxic Thioacetamide Are Not Consistent with Rapid Recovery

2020 ◽  
Vol 21 (23) ◽  
pp. 8918
Author(s):  
Yevgeniya I. Shurubor ◽  
Arthur J. L. Cooper ◽  
Andrey B. Krasnikov ◽  
Elena P. Isakova ◽  
Yulia I. Deryabina ◽  
...  
Keyword(s):  
Liver Function ◽  
Intraperitoneal Injection ◽  
Coenzyme A ◽  
Extended Period ◽  
Rat Tissues ◽  
Delayed Effect ◽  
Acetyl Coa ◽  
Acetyl Coenzyme A ◽  
Acetyl Coenzyme ◽  
Small Biomolecules

Small biomolecules, such as coenzyme A (CoA) and acetyl coenzyme A (acetyl-CoA), play vital roles in the regulation of cellular energy metabolism. In this paper, we evaluated the delayed effect of the potent hepatotoxin thioacetamide (TAA) on the concentrations of CoA and acetyl-CoA in plasma and in different rat tissues. Administration of TAA negatively affects liver function and leads to the development of hepatic encephalopathy (HE). In our experiments, rats were administered a single intraperitoneal injection of TAA at doses of 200, 400, or 600 mg/kg. Plasma, liver, kidney, and brain samples were collected six days after the TAA administration, a period that has been suggested to allow for restoration of liver function. The concentrations of CoA and acetyl-CoA in the group of rats exposed to different doses of TAA were compared to those observed in healthy rats. The results obtained indicate that even a single administration of TAA to rats is sufficient to alter the physiological balance of CoA and acetyl-CoA in the plasma and tissues of rats for an extended period of time. The initial concentrations of CoA and acetyl-CoA were not restored even after the completion of the liver regeneration process.

scholarly journals A Pathway for Degradation of Uracil to Acetyl Coenzyme A in Bacillus megaterium

2020 ◽  
Vol 86 (7) ◽  
Author(s):  
Di Zhu ◽  
Yifeng Wei ◽  
Jinyu Yin ◽  
Dazhi Liu ◽  
Ee Lui Ang ◽  
...  
Keyword(s):  
Energy Source ◽  
Bacillus Megaterium ◽  
Coenzyme A ◽  
Catabolic Pathway ◽  
Acetyl Coa ◽  
Acetyl Coenzyme A ◽  
Content Type ◽  
Biochemical Pathways ◽  
Acetyl Coenzyme

ABSTRACT Bacteria utilize diverse biochemical pathways for the degradation of the pyrimidine ring. The function of the pathways studied to date has been the release of nitrogen for assimilation. The most widespread of these pathways is the reductive pyrimidine catabolic pathway, which converts uracil into ammonia, carbon dioxide, and β-alanine. Here, we report the characterization of a β-alanine:pyruvate aminotransferase (PydD2) and an NAD+-dependent malonic semialdehyde dehydrogenase (MSDH) from a reductive pyrimidine catabolism gene cluster in Bacillus megaterium. Together, these enzymes convert β-alanine into acetyl coenzyme A (acetyl-CoA), a key intermediate in carbon and energy metabolism. We demonstrate the growth of B. megaterium in defined medium with uracil as its sole carbon and energy source. Homologs of PydD2 and MSDH are found in association with reductive pyrimidine pathway genes in many Gram-positive bacteria in the order Bacillales. Our study provides a basis for further investigations of the utilization of pyrimidines as a carbon and energy source by bacteria. IMPORTANCE Pyrimidine has wide occurrence in natural environments, where bacteria use it as a nitrogen and carbon source for growth. Detailed biochemical pathways have been investigated with focus mainly on nitrogen assimilation in the past decades. Here, we report the discovery and characterization of two important enzymes, PydD2 and MSDH, which constitute an extension for the reductive pyrimidine catabolic pathway. These two enzymes, prevalent in Bacillales based on our bioinformatics studies, allow stepwise conversion of β-alanine, a previous “end product” of the reductive pyrimidine degradation pathway, to acetyl-CoA as carbon and energy source.

scholarly journals Protein Acetylation and Acetyl Coenzyme A Metabolism in Budding Yeast

2014 ◽  
Vol 13 (12) ◽  
pp. 1472-1483 ◽  
Author(s):  
Luciano Galdieri ◽  
Tiantian Zhang ◽  
Daniella Rogerson ◽  
Rron Lleshi ◽  
Ales Vancura
Keyword(s):  
Cell Cycle Progression ◽  
Coenzyme A ◽  
Central Position ◽  
Metabolic State ◽  
Acetyl Coa ◽  
Cycle Progression ◽  
Acetyl Coenzyme A ◽  
Cell Functions ◽  
Physical Conditions ◽  
Acetyl Coenzyme

ABSTRACT Cells sense and appropriately respond to the physical conditions and availability of nutrients in their environment. This sensing of the environment and consequent cellular responses are orchestrated by a multitude of signaling pathways and typically involve changes in transcription and metabolism. Recent discoveries suggest that the signaling and transcription machineries are regulated by signals which are derived from metabolism and reflect the metabolic state of the cell. Acetyl coenzyme A (CoA) is a key metabolite that links metabolism with signaling, chromatin structure, and transcription. Acetyl-CoA is produced by glycolysis as well as other catabolic pathways and used as a substrate for the citric acid cycle and as a precursor in synthesis of fatty acids and steroids and in other anabolic pathways. This central position in metabolism endows acetyl-CoA with an important regulatory role. Acetyl-CoA serves as a substrate for lysine acetyltransferases (KATs), which catalyze the transfer of acetyl groups to the epsilon-amino groups of lysines in histones and many other proteins. Fluctuations in the concentration of acetyl-CoA, reflecting the metabolic state of the cell, are translated into dynamic protein acetylations that regulate a variety of cell functions, including transcription, replication, DNA repair, cell cycle progression, and aging. This review highlights the synthesis and homeostasis of acetyl-CoA and the regulation of transcriptional and signaling machineries in yeast by acetylation.

scholarly journals Conversion of 4-Hydroxybutyrate to Acetyl Coenzyme A and Its Anapleurosis in the Metallosphaera sedula 3-Hydroxypropionate/4-Hydroxybutyrate Carbon Fixation Pathway

2014 ◽  
Vol 80 (8) ◽  
pp. 2536-2545 ◽  
Author(s):  
Aaron B. Hawkins ◽  
Michael W. W. Adams ◽  
Robert M. Kelly
Keyword(s):  
Carbon Fixation ◽  
Coenzyme A ◽  
Flux Analysis ◽  
Central Metabolism ◽  
Acetyl Coa ◽  
Acetyl Coenzyme A ◽  
Content Type ◽  
Metallosphaera Sedula ◽  
Acetyl Coenzyme ◽  
Coa Ligase

ABSTRACTThe extremely thermoacidophilic archaeonMetallosphaera sedula(optimum growth temperature, 73°C, pH 2.0) grows chemolithoautotrophically on metal sulfides or molecular hydrogen by employing the 3-hydroxypropionate/4-hydroxybutyrate (3HP/4HB) carbon fixation cycle. This cycle adds two CO2molecules to acetyl coenzyme A (acetyl-CoA) to generate 4HB, which is then rearranged and cleaved to form two acetyl-CoA molecules. Previous metabolic flux analysis showed that two-thirds of central carbon precursor molecules are derived from succinyl-CoA, which is oxidized to malate and oxaloacetate. The remaining one-third is apparently derived from acetyl-CoA. As such, the steps beyond succinyl-CoA are essential for completing the carbon fixation cycle and for anapleurosis of acetyl-CoA. Here, the final four enzymes of the 3HP/4HB cycle, 4-hydroxybutyrate-CoA ligase (AMP forming) (Msed_0406), 4-hydroxybutyryl-CoA dehydratase (Msed_1321), crotonyl-CoA hydratase/(S)-3-hydroxybutyryl-CoA dehydrogenase (Msed_0399), and acetoacetyl-CoA β-ketothiolase (Msed_0656), were produced recombinantly inEscherichia coli, combinedin vitro, and shown to convert 4HB to acetyl-CoA. Metabolic pathways connecting CO2fixation and central metabolism were examined using a gas-intensive bioreactor system in whichM. sedulawas grown under autotrophic (CO2-limited) and heterotrophic conditions. Transcriptomic analysis revealed the importance of the 3HP/4HB pathway in supplying acetyl-CoA to anabolic pathways generating intermediates inM. sedulametabolism. The results indicated that flux between the succinate and acetyl-CoA branches in the 3HP/4HB pathway is governed by 4-hydroxybutyrate-CoA ligase, possibly regulated posttranslationally by the protein acetyltransferase (Pat)/Sir2-dependent system. Taken together, this work confirms the final four steps of the 3HP/4HB pathway, thereby providing the framework for examining connections between CO2fixation and central metabolism inM. sedula.

scholarly journals Mercury methylation in Sphagnum moss mats and its association with sulfate-reducing bacteria in an acidic Adirondack forest lake wetland

2010 ◽  
Vol 74 (3) ◽  
pp. 655-668 ◽  
Author(s):  
Ri-Qing Yu ◽  
Isaac Adatto ◽  
Mario R. Montesdeoca ◽  
Charles T. Driscoll ◽  
Mark E. Hines ◽  
...  
Keyword(s):  
Sulfate Reducing Bacteria ◽  
Mercury Methylation ◽  
Sphagnum Moss ◽  
Sulfate Reducing ◽  
Forest Lake ◽  
Reducing Bacteria
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