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Abdul Halim MF, Fonseca DR, Niehaus TD, Costa KC. Functionally redundant formate dehydrogenases enable formate-dependent growth in Methanococcus maripaludis. J Biol Chem 2024; 300:105550. [PMID: 38072055 PMCID: PMC10805699 DOI: 10.1016/j.jbc.2023.105550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 12/01/2023] [Accepted: 12/02/2023] [Indexed: 01/02/2024] Open
Abstract
Methanogens are essential for the complete remineralization of organic matter in anoxic environments. Most cultured methanogens are hydrogenotrophic, using H2 as an electron donor to reduce CO2 to CH4, but in the absence of H2 many can also use formate. Formate dehydrogenase (Fdh) is essential for formate oxidation, where it transfers electrons for the reduction of coenzyme F420 or to a flavin-based electron bifurcating reaction catalyzed by heterodisulfide reductase (Hdr), the terminal reaction of methanogenesis. Furthermore, methanogens that use formate encode at least two isoforms of Fdh in their genomes, but how these different isoforms participate in methanogenesis is unknown. Using Methanococcus maripaludis, we undertook a biochemical characterization of both Fdh isoforms involved in methanogenesis. Both Fdh1 and Fdh2 interacted with Hdr to catalyze the flavin-based electron bifurcating reaction, and both reduced F420 at similar rates. F420 reduction preceded flavin-based electron bifurcation activity for both enzymes. In a Δfdh1 mutant background, a suppressor mutation was required for Fdh2 activity. Genome sequencing revealed that this mutation resulted in the loss of a specific molybdopterin transferase (moeA), allowing for Fdh2-dependent growth, and the metal content of the proteins suggested that isoforms are dependent on either molybdenum or tungsten for activity. These data suggest that both isoforms of Fdh are functionally redundant, but their activities in vivo may be limited by gene regulation or metal availability under different growth conditions. Together these results expand our understanding of formate oxidation and the role of Fdh in methanogenesis.
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Affiliation(s)
- Mohd Farid Abdul Halim
- Department of Plant and Microbial Biology, University of Minnesota, Twin Cities, St. Paul, Minnesota, USA
| | - Dallas R Fonseca
- Department of Plant and Microbial Biology, University of Minnesota, Twin Cities, St. Paul, Minnesota, USA
| | - Thomas D Niehaus
- Department of Plant and Microbial Biology, University of Minnesota, Twin Cities, St. Paul, Minnesota, USA
| | - Kyle C Costa
- Department of Plant and Microbial Biology, University of Minnesota, Twin Cities, St. Paul, Minnesota, USA.
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Chanderban M, Hill CA, Dhamad AE, Lessner DJ. Expression of V-nitrogenase and Fe-nitrogenase in Methanosarcina acetivorans is controlled by molybdenum, fixed nitrogen, and the expression of Mo-nitrogenase. Appl Environ Microbiol 2023; 89:e0103323. [PMID: 37695043 PMCID: PMC10537573 DOI: 10.1128/aem.01033-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 07/07/2023] [Indexed: 09/12/2023] Open
Abstract
All nitrogen-fixing bacteria and archaea (diazotrophs) use molybdenum (Mo) nitrogenase to reduce dinitrogen (N2) to ammonia, with some also containing vanadium (V) and iron-only (Fe) nitrogenases that lack Mo. Among diazotrophs, the regulation and usage of the alternative V-nitrogenase and Fe-nitrogenase in methanogens are largely unknown. Methanosarcina acetivorans contains nif, vnf, and anf gene clusters encoding putative Mo-nitrogenase, V-nitrogenase, and Fe-nitrogenase, respectively. This study investigated nitrogenase expression and growth by M. acetivorans in response to fixed nitrogen, Mo/V availability, and CRISPRi repression of the nif, vnf, and/or anf gene clusters. The availability of Mo and V significantly affected growth of M. acetivorans with N2 but not with NH4Cl. M. acetivorans exhibited the fastest growth rate and highest cell yield during growth with N2 in medium containing Mo, and the slowest growth in medium lacking Mo and V. qPCR analysis revealed the transcription of the nif operon is only moderately affected by depletion of fixed nitrogen and Mo, whereas vnf and anf transcription increased significantly when fixed nitrogen and Mo were depleted, with removal of Mo being key. Immunoblot analysis revealed Mo-nitrogenase is detected when fixed nitrogen is depleted regardless of Mo availability, while V-nitrogenase and Fe-nitrogenase are detected only in the absence of fixed nitrogen and Mo. CRISPRi repression studies revealed that V-nitrogenase and/or Fe-nitrogenase are required for Mo-independent diazotrophy, and unexpectedly that the expression of Mo-nitrogenase is also required. These results reveal that alternative nitrogenase production in M. acetivorans is tightly controlled and dependent on Mo-nitrogenase expression. IMPORTANCE Methanogens and closely related methanotrophs are the only archaea known or predicted to possess nitrogenase. Methanogens play critical roles in both the global biological nitrogen and carbon cycles. Moreover, methanogens are an ancient microbial lineage and nitrogenase likely originated in methanogens. An understanding of the usage and properties of nitrogenases in methanogens can provide new insight into the evolution of nitrogen fixation and aid in the development nitrogenase-based biotechnology. This study provides the first evidence that a methanogen can produce all three forms of nitrogenases, including simultaneously. The results reveal components of Mo-nitrogenase regulate or are needed to produce V-nitrogenase and Fe-nitrogenase in methanogens, a result not seen in bacteria. Overall, this study provides a foundation to understand the assembly, regulation, and activity of the alternative nitrogenases in methanogens.
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Affiliation(s)
- Melissa Chanderban
- Department of Biological Sciences, University of Arkansas-Fayetteville, Fayetteville, Arkansas, USA
| | - Christopher A. Hill
- Department of Biological Sciences, University of Arkansas-Fayetteville, Fayetteville, Arkansas, USA
| | - Ahmed E. Dhamad
- Department of Biological Sciences, University of Arkansas-Fayetteville, Fayetteville, Arkansas, USA
- Department of Biological Sciences, Wasit University, Wasit, Iraq
| | - Daniel J. Lessner
- Department of Biological Sciences, University of Arkansas-Fayetteville, Fayetteville, Arkansas, USA
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Fonseca DR, Loppnow MB, Day LA, Kelsey EL, Abdul Halim MF, Costa KC. Random transposon mutagenesis identifies genes essential for transformation in Methanococcus maripaludis. Mol Genet Genomics 2023. [PMID: 36823423 DOI: 10.1007/s00438-023-01994-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 01/15/2023] [Indexed: 02/25/2023]
Abstract
Natural transformation, the process whereby a cell acquires DNA directly from the environment, is an important driver of evolution in microbial populations, yet the mechanism of DNA uptake is only characterized in bacteria. To expand our understanding of natural transformation in archaea, we undertook a genetic approach to identify a catalog of genes necessary for transformation in Methanococcus maripaludis. Using an optimized method to generate random transposon mutants, we screened 6144 mutant strains for defects in natural transformation and identified 25 transformation-associated candidate genes. Among these are genes encoding components of the type IV-like pilus, transcription/translation associated genes, genes encoding putative membrane bound transport proteins, and genes of unknown function. Interestingly, similar genes were identified regardless of whether replicating or integrating plasmids were provided as a substrate for transformation. Using allelic replacement mutagenesis, we confirmed that several genes identified in these screens are essential for transformation. Finally, we identified a homolog of a membrane bound substrate transporter in Methanoculleus thermophilus and verified its importance for transformation using allelic replacement mutagenesis, suggesting a conserved mechanism for DNA transfer in multiple archaea. These data represent an initial characterization of the genes important for transformation which will inform efforts to understand gene flow in natural populations. Additionally, knowledge of the genes necessary for natural transformation may assist in identifying signatures of transformation machinery in archaeal genomes and aid the establishment of new model genetic systems for studying archaea.
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Vallejos-Baccelliere G, Kaufman SB, González-Lebrero RM, Castro-Fernandez V, Guixé V. Characterisation of kinetics, substrate inhibition and product activation by AMP of bifunctional ADP-dependent glucokinase/phosphofructokinase from Methanococcus maripaludis. FEBS J 2022; 289:7519-7536. [PMID: 35717557 DOI: 10.1111/febs.16557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 05/20/2022] [Accepted: 06/16/2022] [Indexed: 01/14/2023]
Abstract
Methanogenic archaea have received attention due to their potential use in biotechnological applications such as methane production, so their metabolism and regulation are topics of special interest. When growing in a nutrient-rich medium, these organisms exhibit gluconeogenic metabolism; however, under starvation conditions, they turn to glycolytic metabolism. To date, no regulatory mechanism has been described for this gluconeogenic/glycolytic metabolic switch. Here, we report that adenosine monophosphate (AMP) activates both enzymatic activities of the bifunctional adenosine diphosphate (ADP)-dependent phosphofructokinase/glucokinase from Methanococcus maripaludis (MmPFK/GK). To understand this phenomenon, we performed a comprehensive kinetic characterisation, including determination of the kinetics, substrate inhibition and AMP activation mechanism of this enzyme. We determined that MmPFK/GK has an ordered-sequential mechanism, in which MgADP is the first substrate to bind and AMP is the last product released. The enzyme also displays substrate inhibition by both sugar substrates; we determined that this inhibition occurs through the formation of catalytically nonproductive enzyme complexes caused by sugar binding. For both activities, the AMP activation mechanism occurs primarily through incremental changes in the affinity for the sugar substrate, with this effect being higher in the GK than in the PFK activity. Interestingly, due to the increase in the sugar substrate affinity caused by AMP, an enhancement in the sugar substrate inhibition effect was also observed for both activities, which can be explained by an increase in sugar binding leading to the formation of dead-end complexes. These results shed light on the regulatory mechanisms of methanogenic archaeal sugar metabolism, a phenomenon that has been largely unexplored.
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Affiliation(s)
- Gabriel Vallejos-Baccelliere
- Laboratorio de Bioquímica y Biología Molecular, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Sergio B Kaufman
- Departamento de Química Biológica, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires - IQUIFIB (UBA-CONICET), Argentina
| | - Rodolfo M González-Lebrero
- Departamento de Química Biológica, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires - IQUIFIB (UBA-CONICET), Argentina
| | - Víctor Castro-Fernandez
- Laboratorio de Bioquímica y Biología Molecular, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Victoria Guixé
- Laboratorio de Bioquímica y Biología Molecular, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
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Li J, Akinyemi TS, Shao N, Chen C, Dong X, Liu Y, Whitman WB. Genetic and Metabolic Engineering of Methanococcus spp. Current Research in Biotechnology 2022. [DOI: 10.1016/j.crbiot.2022.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Thevasundaram K, Gallagher JJ, Cherng F, Chang MCY. Engineering nonphotosynthetic carbon fixation for production of bioplastics by methanogenic archaea. Proc Natl Acad Sci U S A 2022; 119:e2118638119. [PMID: 35639688 DOI: 10.1073/pnas.2118638119] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
SignificanceBiological carbon fixation provides opportunities to directly utilize CO2 to synthesize a broad range of value-added compounds, potentially displacing petroleum feedstock use in industry. Chemoautotrophs are particularly interesting as their carbon fixation can be driven chemically by renewable H2 in place of light, which can limit industrial fermentation of photosynthetic organisms. We describe the development of a methanogenic host, Methanococcus maripaludis, for metabolic engineering. Since redox cofactors used in upstream archaeal carbon fixation pathways are orthogonal to typical downstream biosynthetic pathways, it was necessary to engineer both NADH biosynthesis and turnover. In doing so, we are able to show that methanogenic archaea can, indeed, serve as a platform for the high-yield production of bioplastics and monomers from CO2 and H2.
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Cong S, Xu Y, Lu Y. Growth Coordination Between Butyrate-Oxidizing Syntrophs and Hydrogenotrophic Methanogens. Front Microbiol 2021; 12:742531. [PMID: 34603271 PMCID: PMC8481629 DOI: 10.3389/fmicb.2021.742531] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 08/18/2021] [Indexed: 11/13/2022] Open
Abstract
Syntrophy is a thermodynamically required mutualistic cooperation between fatty acid-oxidizing bacteria and methanogens that plays the important role in organic decomposition and methanogenesis in anoxic environments. In this study, three experiments were conducted to evaluate the cell-to-cell interaction in a thermophilic coculture consisting of Syntrophothermus lipocalidus and Methanocella conradii and a mesophilic coculture consisting of Syntrophomonas wolfei and Methanococcus maripaludis. First, syntrophs and methanogens were inoculated at different initial cell ratios to evaluate the growth synchronization. The quantitative PCR analysis revealed that the organism with a lower relative abundance at the beginning always grew faster, and the cell ratio converged over time to relative constant values in both the thermophilic and mesophilic cocultures. Next, intermittent ultrasound and constant shaking treatments were used to evaluate the influence of physical disturbance on microbial aggregation in the mesophilic coculture. The fluorescence in situ hybridization and scanning electron microscopy revealed that the tendency of syntrophic aggregation was not affected by the physical disturbances, although the activity was slightly depressed. Syntrophomonas dominated in the initial microbial aggregates, which, however, did not grow until Methanococcus was attached and increased to a significant extent, indicating the local growth synchronization during the formation and maturation of syntrophic aggregates. Last, microfluidic experiments revealed that whether or not Syntrophomonas or Methanococcus was loaded first, the second organism preferred moving to the place where the first organism was located, suggesting the cell-to-cell attraction between Syntrophomonas and Methanococcus. Collectively, our study demonstrated the growth synchronization and cell-to-cell attraction between the butyrate-oxidizing bacteria and methanogens for optimizing the syntrophic cooperation.
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Affiliation(s)
- Shuqi Cong
- College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Yiqin Xu
- College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Yahai Lu
- College of Urban and Environmental Sciences, Peking University, Beijing, China
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Long F, Cheung CY, Whitman WB, Cook GM, Ronimus RS. Using genome comparisons of wild-type and resistant mutants of Methanococcus maripaludis to help understand mechanisms of resistance to methane inhibitors. Access Microbiol 2021; 3:000244. [PMID: 34595395 PMCID: PMC8479958 DOI: 10.1099/acmi.0.000244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 06/08/2021] [Indexed: 11/24/2022] Open
Abstract
Methane emissions from enteric fermentation in the ruminant digestive system generated by methanogenic archaea are a significant contributor to anthropogenic greenhouse gas emissions. Additionally, methane produced as an end-product of enteric fermentation is an energy loss from digested feed. To control the methane emissions from ruminants, extensive research in the last decades has been focused on developing viable enteric methane mitigation practices, particularly, using methanogen-specific inhibitors. We report here the utilization of two known inhibitors of methanogenic archaea, neomycin and chloroform, together with a recently identified inhibitor, echinomycin, to produce resistant mutants of Methanococcus maripaludis S2 and S0001. Whole-genome sequencing at high coverage (> 100-fold) was performed subsequently to investigate the potential targets of these inhibitors at the genomic level. Upon analysis of the whole-genome sequencing data, we identified mutations in a number of genetic loci pointing to potential mechanisms of inhibitor action and their underlying mechanisms of resistance.
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Affiliation(s)
- Feng Long
- Department of Microbiology, University of Georgia, Athens, Georgia, USA
- Present address: Department of Inflammation and Immunity, Cleveland Clinic, Cleveland, OH, USA
| | - Chen-Yi Cheung
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - William B Whitman
- Department of Microbiology, University of Georgia, Athens, Georgia, USA
| | - Gregory M Cook
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Ron S Ronimus
- Rumen Microbiology, AgResearch Ltd., Palmerston North, New Zealand
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9
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Chan PP, Lin BY, Mak AJ, Lowe TM. tRNAscan-SE 2.0: improved detection and functional classification of transfer RNA genes. Nucleic Acids Res 2021; 49:9077-9096. [PMID: 34417604 PMCID: PMC8450103 DOI: 10.1093/nar/gkab688] [Citation(s) in RCA: 422] [Impact Index Per Article: 140.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/23/2021] [Accepted: 07/27/2021] [Indexed: 12/17/2022] Open
Abstract
tRNAscan-SE has been widely used for transfer RNA (tRNA) gene prediction for over twenty years, developed just as the first genomes were decoded. With the massive increase in quantity and phylogenetic diversity of genomes, the accurate detection and functional prediction of tRNAs has become more challenging. Utilizing a vastly larger training set, we created nearly one hundred specialized isotype- and clade-specific models, greatly improving tRNAscan-SE’s ability to identify and classify both typical and atypical tRNAs. We employ a new comparative multi-model strategy where predicted tRNAs are scored against a full set of isotype-specific covariance models, allowing functional prediction based on both the anticodon and the highest-scoring isotype model. Comparative model scoring has also enhanced the program's ability to detect tRNA-derived SINEs and other likely pseudogenes. For the first time, tRNAscan-SE also includes fast and highly accurate detection of mitochondrial tRNAs using newly developed models. Overall, tRNA detection sensitivity and specificity is improved for all isotypes, particularly those utilizing specialized models for selenocysteine and the three subtypes of tRNA genes encoding a CAU anticodon. These enhancements will provide researchers with more accurate and detailed tRNA annotation for a wider variety of tRNAs, and may direct attention to tRNAs with novel traits.
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Affiliation(s)
- Patricia P Chan
- Department of Biomolecular Engineering, Baskin School of Engineering, University of California, Santa Cruz, CA 95064, USA
| | - Brian Y Lin
- Department of Biomolecular Engineering, Baskin School of Engineering, University of California, Santa Cruz, CA 95064, USA
| | - Allysia J Mak
- Department of Biomolecular Engineering, Baskin School of Engineering, University of California, Santa Cruz, CA 95064, USA
| | - Todd M Lowe
- Department of Biomolecular Engineering, Baskin School of Engineering, University of California, Santa Cruz, CA 95064, USA
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Holten MP, Fonseca DR, Costa KC. The Oligosaccharyltransferase AglB Supports Surface-Associated Growth and Iron Oxidation in Methanococcus maripaludis. Appl Environ Microbiol 2021; 87:e0099521. [PMID: 34132588 DOI: 10.1128/AEM.00995-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Most microbial organisms grow as surface-attached communities known as biofilms. However, the mechanisms whereby methanogenic archaea grow attached to surfaces have remained understudied. Here, we show that the oligosaccharyltransferase AglB is essential for growth of Methanococcus maripaludis strain JJ on glass or metal surfaces. AglB glycosylates several cellular structures, such as pili, archaella, and the cell surface layer (S-layer). We show that the S-layer of strain JJ, but not strain S2, is a glycoprotein, that only strain JJ was capable of growth on surfaces, and that deletion of aglB blocked S-layer glycosylation and abolished surface-associated growth. A strain JJ mutant lacking structural components of the type IV-like pilus did not have a growth defect under any conditions tested, while a mutant lacking the preflagellin peptidase (ΔflaK) was defective for surface growth only when formate was provided as the sole electron donor. Finally, for strains that are capable of Fe0 oxidation, we show that deletion of aglB decreases the rate of anaerobic Fe0 oxidation, presumably due to decreased association of biomass with the Fe0 surface. Together, these data provide an initial characterization of surface-associated growth in a member of the methanogenic archaea. IMPORTANCE Methanogenic archaea are responsible for producing the majority of methane on Earth and catalyze the terminal reactions in the degradation of organic matter in anoxic environments. Methanogens often grow as biofilms associated with surfaces or partner organisms; however, the molecular details of surface-associated growth remain uncharacterized. We have found evidence that glycosylation of the cell surface layer is essential for growth of M. maripaludis on surfaces and can enhance rates of anaerobic iron corrosion. These results provide insight into the physiology of surface-associated methanogenic organisms and highlight the importance of surface association for anaerobic iron corrosion.
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Kakuk B, Wirth R, Maróti G, Szuhaj M, Rakhely G, Laczi K, Kovács KL, Bagi Z. Early response of methanogenic archaea to H 2 as evaluated by metagenomics and metatranscriptomics. Microb Cell Fact 2021; 20:127. [PMID: 34217274 PMCID: PMC8254922 DOI: 10.1186/s12934-021-01618-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Accepted: 06/24/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The molecular machinery of the complex microbiological cell factory of biomethane production is not fully understood. One of the process control elements is the regulatory role of hydrogen (H2). Reduction of carbon dioxide (CO2) by H2 is rate limiting factor in methanogenesis, but the community intends to keep H2 concentration low in order to maintain the redox balance of the overall system. H2 metabolism in methanogens becomes increasingly important in the Power-to-Gas renewable energy conversion and storage technologies. RESULTS The early response of the mixed mesophilic microbial community to H2 gas injection was investigated with the goal of uncovering the first responses of the microbial community in the CH4 formation and CO2 mitigation Power-to-Gas process. The overall microbial composition changes, following a 10 min excessive bubbling of H2 through the reactor, was investigated via metagenome and metatranscriptome sequencing. The overall composition and taxonomic abundance of the biogas producing anaerobic community did not change appreciably 2 hours after the H2 treatment, indicating that this time period was too short to display differences in the proliferation of the members of the microbial community. There was, however, a substantial increase in the expression of genes related to hydrogenotrophic methanogenesis of certain groups of Archaea. As an early response to H2 exposure the activity of the hydrogenotrophic methanogenesis in the genus Methanoculleus was upregulated but the hydrogenotrophic pathway in genus Methanosarcina was downregulated. The RT-qPCR data corroborated the metatranscriptomic RESULTS: H2 injection also altered the metabolism of a number of microbes belonging in the kingdom Bacteria. Many Bacteria possess the enzyme sets for the Wood-Ljungdahl pathway. These and the homoacetogens are partners for syntrophic community interactions between the distinct kingdoms of Archaea and Bacteria. CONCLUSIONS External H2 regulates the functional activity of certain Bacteria and Archaea. The syntrophic cross-kingdom interactions in H2 metabolism are important for the efficient operation of the Power-to-Gas process. Therefore, mixed communities are recommended for the large scale Power-to-Gas process rather than single hydrogenotrophic methanogen strains. Fast and reproducible response from the microbial community can be exploited in turn-off and turn-on of the Power-to-Gas microbial cell factories.
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Affiliation(s)
- Balázs Kakuk
- Institute of Medical Biology, University of Szeged, Szeged, Hungary
- Department of Biotechnology, University of Szeged, Szeged, Hungary
| | - Roland Wirth
- Department of Biotechnology, University of Szeged, Szeged, Hungary
- Institute of Plant Biology, Biological Research Center, Szeged, Hungary
| | - Gergely Maróti
- Institute of Plant Biology, Biological Research Center, Szeged, Hungary
| | - Márk Szuhaj
- Department of Biotechnology, University of Szeged, Szeged, Hungary
| | - Gábor Rakhely
- Department of Biotechnology, University of Szeged, Szeged, Hungary
- Institute of Biophysics, Biological Research Center, Szeged, Hungary
| | - Krisztián Laczi
- Department of Biotechnology, University of Szeged, Szeged, Hungary
| | - Kornél L Kovács
- Department of Biotechnology, University of Szeged, Szeged, Hungary.
- Department of Oral Biology and Experimental Dental Research, University of Szeged, Szeged, Hungary.
| | - Zoltán Bagi
- Department of Biotechnology, University of Szeged, Szeged, Hungary.
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Prorok P, Grin IR, Matkarimov BT, Ishchenko AA, Laval J, Zharkov DO, Saparbaev M. Evolutionary Origins of DNA Repair Pathways: Role of Oxygen Catastrophe in the Emergence of DNA Glycosylases. Cells 2021; 10:1591. [PMID: 34202661 DOI: 10.3390/cells10071591] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 06/17/2021] [Accepted: 06/18/2021] [Indexed: 11/23/2022] Open
Abstract
It was proposed that the last universal common ancestor (LUCA) evolved under high temperatures in an oxygen-free environment, similar to those found in deep-sea vents and on volcanic slopes. Therefore, spontaneous DNA decay, such as base loss and cytosine deamination, was the major factor affecting LUCA’s genome integrity. Cosmic radiation due to Earth’s weak magnetic field and alkylating metabolic radicals added to these threats. Here, we propose that ancient forms of life had only two distinct repair mechanisms: versatile apurinic/apyrimidinic (AP) endonucleases to cope with both AP sites and deaminated residues, and enzymes catalyzing the direct reversal of UV and alkylation damage. The absence of uracil–DNA N-glycosylases in some Archaea, together with the presence of an AP endonuclease, which can cleave uracil-containing DNA, suggests that the AP endonuclease-initiated nucleotide incision repair (NIR) pathway evolved independently from DNA glycosylase-mediated base excision repair. NIR may be a relic that appeared in an early thermophilic ancestor to counteract spontaneous DNA damage. We hypothesize that a rise in the oxygen level in the Earth’s atmosphere ~2 Ga triggered the narrow specialization of AP endonucleases and DNA glycosylases to cope efficiently with a widened array of oxidative base damage and complex DNA lesions.
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Alqahtani MF, Bajracharya S, Katuri KP, Ali M, Xu J, Alarawi MS, Saikaly PE. Enrichment of salt-tolerant CO 2-fixing communities in microbial electrosynthesis systems using porous ceramic hollow tube wrapped with carbon cloth as cathode and for CO 2 supply. Sci Total Environ 2021; 766:142668. [PMID: 33077225 DOI: 10.1016/j.scitotenv.2020.142668] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 09/20/2020] [Accepted: 09/20/2020] [Indexed: 06/11/2023]
Abstract
Microbial inocula from marine origins are less explored for CO2 reduction in microbial electrosynthesis (MES) system, although effective CO2-fixing communities in marine environments are well-documented. We explored natural saline habitats, mainly salt marsh (SM) and mangrove (M) sediments, as potential inoculum sources for enriching salt-tolerant CO2 reducing community using two enrichment strategies: H2:CO2 (80:20) enrichment in serum vials and enrichment in cathode chamber of MES reactors operated at -1.0 V vs. Ag/AgCl. Porous ceramic hollow tube wrapped with carbon cloth was used as cathode and for direct CO2 delivery to CO2 reducing communities growing on the cathode surface. Methanogenesis was dominant in both the M- and SM-seeded MES and the methanogenic Archaea Methanococcus was the most dominant genus. Methane production was slightly higher in the SM-seeded MES (4.9 ± 1.7 mmol) compared to the M-seeded MES (3.8 ± 1.1 mmol). In contrast, acetate production was almost two times higher in the M-seeded MES (3.1 ± 0.9 mmol) than SM-seeded MES (1.5 ± 1.3 mmol). The high relative abundance of the genus Acetobacterium in the M-seeded serum vials correlates with the high acetate production obtained. The different enrichment strategies affected the community composition, though the communities in MES reactors and serum vials were performing similar functions (methanogenesis and acetogenesis). Despite similar operating conditions, the microbial community composition of M-seeded serum vials and MES reactors differed from the SM-seeded serum vials and MES reactors, supporting the importance of inoculum source in the evolution of CO2-reducing microbial communities.
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Affiliation(s)
- Manal F Alqahtani
- Biological and Environmental Science and Engineering (BESE) Division, Water Desalination and Reuse Center, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Suman Bajracharya
- Biological and Environmental Science and Engineering (BESE) Division, Water Desalination and Reuse Center, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Krishna P Katuri
- Biological and Environmental Science and Engineering (BESE) Division, Water Desalination and Reuse Center, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Muhammad Ali
- Biological and Environmental Science and Engineering (BESE) Division, Water Desalination and Reuse Center, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Jiajie Xu
- Biological and Environmental Science and Engineering (BESE) Division, Water Desalination and Reuse Center, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Mohammed S Alarawi
- Computational Biosciences Research Center, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Pascal E Saikaly
- Biological and Environmental Science and Engineering (BESE) Division, Water Desalination and Reuse Center, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia.
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14
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Zhu X, Chen Y, Liu X, Li D. Effects of higher temperature on antibiotic resistance genes for in-situ biogas upgrading reactors with H 2 addition. Sci Total Environ 2021; 764:144639. [PMID: 33401045 DOI: 10.1016/j.scitotenv.2020.144639] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/10/2020] [Accepted: 12/14/2020] [Indexed: 06/12/2023]
Abstract
In-situ biogas upgrading by H2 injection is a promising method for bio-natural gas production, yet the effect of H2 addition on antibiotic resistance genes during the in-situ biogas upgrading process remains unknown. We analyzed mesophilic and thermophilic in-situ biogas upgrading digesters with intermittent or continuous mixing models using metagenomic and metatranscriptomic methods to evaluate the effects of H2 addition on antibiotic resistance profiles. We found that H2 addition had less impact in the mesophilic reactor. In the thermophilic reactor, the influenced antibiotic resistance ontology (AROs) was mostly bound to the integral membrane transporters of the ATP-binding cassette and major facilitator superfamily. The annotated gene numbers of four drug classes, including macrolide, glycopeptide, lincosamide, and fluoroquinolone, increased distinctly after H2 addition. Acetate concentration is a vital indicator for distinguishing the abundance of different antibiotic efflux pumps. Most of the AROs influenced by Ruminiclostridium replaced the original dominant species Clostridium, and the versatile genus Methanosarcina was the sole methanogen correlated with the altered AROs of efflux pumps conferring antibiotic resistance. The introduced H2 was synthesized to CH4via the hydrogenotrophic pathway of Methanosarcina flavescens, and part of the consumed H2 was used for cell growth.
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Affiliation(s)
- Xianpu Zhu
- Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Science, Chengdu 610041, China; Biomass Energy Engineering Research Centre, School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Yichao Chen
- Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Science, Chengdu 610041, China
| | - Xiaofeng Liu
- Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Science, Chengdu 610041, China
| | - Dong Li
- Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Science, Chengdu 610041, China.
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15
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Shalvarjian KE, Nayak DD. Transcriptional regulation of methanogenic metabolism in archaea. Curr Opin Microbiol 2021; 60:8-15. [PMID: 33561735 DOI: 10.1016/j.mib.2021.01.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 01/21/2021] [Accepted: 01/21/2021] [Indexed: 11/25/2022]
Abstract
Methanogenesis is a widespread metabolism of evolutionary and environmental importance that is likely to have originated on early Earth. Microorganisms that perform methanogenesis, termed methanogens, belong exclusively to the domain Archaea. Despite maintaining eukaryotic transcription machinery and homologs of bacterial regulators, archaeal transcription and gene regulation appear to be distinct from either domain. While genes involved in methanogenic metabolism have been identified and characterized, their regulation in response to both extracellular and intracellular signals is less understood. Here, we review recent reports on transcriptional regulation of methanogenesis using two model methanogens, Methanococcus maripaludis and Methanosarcina acetivorans, and highlight directions for future research in this nascent field.
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Affiliation(s)
- Katie E Shalvarjian
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - Dipti D Nayak
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA.
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16
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Fonseca DR, Halim MFA, Holten MP, Costa KC. Type IV-Like Pili Facilitate Transformation in Naturally Competent Archaea. J Bacteriol 2020; 202:e00355-20. [PMID: 32817089 DOI: 10.1128/JB.00355-20] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 08/07/2020] [Indexed: 12/19/2022] Open
Abstract
Naturally competent organisms are capable of DNA uptake directly from the environment through the process of transformation. Despite the importance of transformation to microbial evolution, DNA uptake remains poorly characterized outside of the bacterial domain. Here, we identify the pilus as a necessary component of the transformation machinery in archaea. We describe two naturally competent organisms, Methanococcus maripaludis and Methanoculleus thermophilus In M. maripaludis, replicative vectors were transferred with an average efficiency of 2.4 × 103 transformants μg-1 DNA. In M. thermophilus, integrative vectors were transferred with an average efficiency of 2.7 × 103 transformants μg-1 DNA. Additionally, natural transformation of M. thermophilus could be used to introduce chromosomal mutations. To our knowledge, this is the first demonstration of a method to introduce targeted mutations in a member of the order Methanomicrobiales For both organisms, mutants lacking structural components of the type IV-like pilus filament were defective for DNA uptake, demonstrating the importance of pili for natural transformation. Interestingly, competence could be induced in a noncompetent strain of M. maripaludis by expressing pilin genes from a replicative vector. These results expand the known natural competence pili to include examples from the archaeal domain and highlight the importance of pili for DNA uptake in diverse microbial organisms.IMPORTANCE Microbial organisms adapt and evolve by acquiring new genetic material through horizontal gene transfer. One way that this occurs is natural transformation, the direct uptake and genomic incorporation of environmental DNA by competent organisms. Archaea represent up to a third of the biodiversity on Earth, yet little is known about transformation in these organisms. Here, we provide the first characterization of a component of the archaeal DNA uptake machinery. We show that the type IV-like pilus is essential for natural transformation in two archaeal species. This suggests that pili are important for transformation across the tree of life and further expands our understanding of gene flow in archaea.
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Vo CH, Goyal N, Karimi IA, Kraft M. First Observation of an Acetate Switch in a Methanogenic Autotroph ( Methanococcus maripaludis S2). Microbiol Insights 2020; 13:1178636120945300. [PMID: 32843840 PMCID: PMC7416134 DOI: 10.1177/1178636120945300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 07/01/2020] [Indexed: 11/17/2022] Open
Abstract
The transition from acetate production by a microorganism in its early growth phase to acetate re-uptake in its late growth phase has been termed acetate switch. It has been observed in several heterotrophic prokaryotes, but not in an autotroph. Furthermore, all reports hitherto have involved the tricarboxylic acid cycle. This study reports the first observation of acetate switch in a methanogenic autotroph Methanococcus maripaludis S2, which uses the Wolfe cycle for its anaerobic respiration. When grown in minimal medium with carbon dioxide as the sole carbon source, and either ammonium or dinitrogen as the sole nitrogen source, M. maripaludis S2 dissimilated acetate in the early growth phase and assimilated it back in the late growth phase. The acetate switch was more pronounced in the dinitrogen-grown cultures. We postulate that the acetate dissimilation in M. maripaludis S2 may serve as a metabolic outlet for the carbon overflow in the early growth phase, and the assimilation in the late growth phase may be due to the scarcity of the carbon source. Based on the primary and secondary protein structures, we propose that MMP0253 may function as the adenosine diphosphate (ADP)-forming acetyl-CoA synthetase to catalyse acetate formation from acetyl-CoA. To verify this, we produced MMP0253 via the ligation-independent cloning technique in Escherichia coli strain Rosetta (DE3) using pNIC28-Bsa4 as the vector. The recombinant protein showed catalytic activity, when added into a mixture of acetyl-CoA, ADP, and inorganic phosphate (Pi). The concentration profile of acetate, together with the enzymatic activity of MMP0253, shows that M. maripaludis S2 can produce acetate and exhibit an acetate switch.
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Affiliation(s)
- Chi Hung Vo
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore.,Cambridge Centre for Advanced Research and Education in Singapore Ltd, Singapore
| | - Nishu Goyal
- Department of Chemical Engineering, University of Petroleum and Energy Studies, Dehradun, India
| | - Iftekhar A Karimi
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore.,Cambridge Centre for Advanced Research and Education in Singapore Ltd, Singapore
| | - Markus Kraft
- Cambridge Centre for Advanced Research and Education in Singapore Ltd, Singapore.,Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK.,School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore
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Wells M, Kanmanii NJ, Al Zadjali AM, Janecka JE, Basu P, Oremland RS, Stolz JF. Methane, arsenic, selenium and the origins of the DMSO reductase family. Sci Rep 2020; 10:10946. [PMID: 32616801 DOI: 10.1038/s41598-020-67892-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 06/16/2020] [Indexed: 11/16/2022] Open
Abstract
Mononuclear molybdoenzymes of the dimethyl sulfoxide reductase (DMSOR) family catalyze a number of reactions essential to the carbon, nitrogen, sulfur, arsenic, and selenium biogeochemical cycles. These enzymes are also ancient, with many lineages likely predating the divergence of the last universal common ancestor into the Bacteria and Archaea domains. We have constructed rooted phylogenies for over 1,550 representatives of the DMSOR family using maximum likelihood methods to investigate the evolution of the arsenic biogeochemical cycle. The phylogenetic analysis provides compelling evidence that formylmethanofuran dehydrogenase B subunits, which catalyze the reduction of CO2 to formate during hydrogenotrophic methanogenesis, constitutes the most ancient lineage. Our analysis also provides robust support for selenocysteine as the ancestral ligand for the Mo/W atom. Finally, we demonstrate that anaerobic arsenite oxidase and respiratory arsenate reductase catalytic subunits represent a more ancient lineage of DMSORs compared to aerobic arsenite oxidase catalytic subunits, which evolved from the assimilatory nitrate reductase lineage. This provides substantial support for an active arsenic biogeochemical cycle on the anoxic Archean Earth. Our work emphasizes that the use of chalcophilic elements as substrates as well as the Mo/W ligand in DMSORs has indelibly shaped the diversification of these enzymes through deep time.
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20
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Lyu Z, Shao N, Chou CW, Shi H, Patel R, Duin EC, Whitman WB. Posttranslational Methylation of Arginine in Methyl Coenzyme M Reductase Has a Profound Impact on both Methanogenesis and Growth of Methanococcus maripaludis. J Bacteriol 2020; 202:e00654-19. [PMID: 31740491 DOI: 10.1128/JB.00654-19] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 11/09/2019] [Indexed: 02/05/2023] Open
Abstract
Catalyzing the key step for anaerobic production and/or oxidation of methane and likely other short-chain alkanes, methyl coenzyme M reductase (Mcr) and its homologs play a key role in the global carbon cycle. The McrA subunit possesses up to five conserved posttranslational modifications (PTMs) at its active site. It was previously suggested that methanogenesis marker protein 10 (Mmp10) could play an important role in methanogenesis. To systematically examine its physiological role, mmpX (locus tag MMP1554), the gene encoding Mmp10 in Methanococcus maripaludis, was deleted with a new genetic tool, resulting in the complete loss of the 5-C-(S)-methylarginine PTM of residue 275 in the McrA subunit. When the ΔmmpX mutant was complemented with the wild-type gene expressed by either a strong or a weak promoter, methylation was fully restored. Compared to the parental strain, maximal rates of methane formation by whole cells were reduced by 40 to 60% in the ΔmmpX mutant. The reduction in activity was fully reversed by the complement with the strong promoter. Site-directed mutagenesis of mmpX resulted in a differential loss of arginine methylation among the mutants in vivo, suggesting that activities of Mmp10 directly modulated methylation. R275 was present in a highly conserved PXRR275(A/S)R(G/A) signature sequence in McrAs. The only other protein in M. maripaludis containing a similar sequence was not methylated, suggesting that Mmp10 is specific for McrA. In conclusion, Mmp10 modulates the methyl-Arg PTM on McrA in a highly specific manner, which has a profound impact on Mcr activity.IMPORTANCE Mcr is the key enzyme in methanogenesis and a promising candidate for bioengineering the conversion of methane to liquid fuel. Our knowledge of Mcr is still limited. In terms of complexity, uniqueness, and environmental importance, Mcr is more comparable to photosynthetic reaction centers than conventional enzymes. PTMs have long been hypothesized to play key roles in modulating Mcr activity. Here, we directly link the mmpX gene to the arginine PTM of Mcr, demonstrate its association with methanogenesis activity, and offer insights into its substrate specificity and putative cofactor binding sites. This is also the first time that a PTM of McrA has been shown to have a substantial impact on both methanogenesis and growth in the absence of additional stressors.
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Rother M, Quitzke V. Selenoprotein synthesis and regulation in Archaea. Biochim Biophys Acta Gen Subj 2018; 1862:2451-2462. [DOI: 10.1016/j.bbagen.2018.04.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 04/09/2018] [Accepted: 04/10/2018] [Indexed: 01/23/2023]
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22
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Quitzke V, Fersch J, Seyhan D, Rother M. Selenium-dependent gene expression in Methanococcus maripaludis: Involvement of the transcriptional regulator HrsM. Biochim Biophys Acta Gen Subj 2018; 1862:2441-2450. [DOI: 10.1016/j.bbagen.2018.03.030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 03/28/2018] [Accepted: 03/29/2018] [Indexed: 01/23/2023]
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23
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Tsurumaru H, Ito N, Mori K, Wakai S, Uchiyama T, Iino T, Hosoyama A, Ataku H, Nishijima K, Mise M, Shimizu A, Harada T, Horikawa H, Ichikawa N, Sekigawa T, Jinno K, Tanikawa S, Yamazaki J, Sasaki K, Yamazaki S, Fujita N, Harayama S. An extracellular [NiFe] hydrogenase mediating iron corrosion is encoded in a genetically unstable genomic island in Methanococcus maripaludis. Sci Rep 2018; 8:15149. [PMID: 30310166 PMCID: PMC6181927 DOI: 10.1038/s41598-018-33541-5] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 10/01/2018] [Indexed: 11/09/2022] Open
Abstract
Certain methanogens deteriorate steel surfaces through a process called microbiologically influenced corrosion (MIC). However, the mechanisms of MIC, whereby methanogens oxidize zerovalent iron (Fe0), are largely unknown. In this study, Fe0-corroding Methanococcus maripaludis strain OS7 and its derivative (strain OS7mut1) defective in Fe0-corroding activity were isolated. Genomic analysis of these strains demonstrated that the strain OS7mut1 contained a 12-kb chromosomal deletion. The deleted region, termed "MIC island", encoded the genes for the large and small subunits of a [NiFe] hydrogenase, the TatA/TatC genes necessary for the secretion of the [NiFe] hydrogenase, and a gene for the hydrogenase maturation protease. Thus, the [NiFe] hydrogenase may be secreted outside the cytoplasmic membrane, where the [NiFe] hydrogenase can make direct contact with Fe0, and oxidize it, generating hydrogen gas: Fe0 + 2 H+ → Fe2+ + H2. Comparative analysis of extracellular and intracellular proteomes of strain OS7 supported this hypothesis. The identification of the MIC genes enables the development of molecular tools to monitor epidemiology, and to perform surveillance and risk assessment of MIC-inducing M. maripaludis.
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Affiliation(s)
- Hirohito Tsurumaru
- NITE Biological Resource Center (NBRC), National Institute of Technology and Evaluation (NITE), Chiba, 292-0818, Japan
| | - Naofumi Ito
- NITE Biological Resource Center (NBRC), National Institute of Technology and Evaluation (NITE), Chiba, 292-0818, Japan
| | - Koji Mori
- NITE Biological Resource Center (NBRC), National Institute of Technology and Evaluation (NITE), Chiba, 292-0818, Japan
| | - Satoshi Wakai
- NITE Biological Resource Center (NBRC), National Institute of Technology and Evaluation (NITE), Chiba, 292-0818, Japan
| | - Taku Uchiyama
- NITE Biological Resource Center (NBRC), National Institute of Technology and Evaluation (NITE), Chiba, 292-0818, Japan
| | - Takao Iino
- NITE Biological Resource Center (NBRC), National Institute of Technology and Evaluation (NITE), Chiba, 292-0818, Japan
| | - Akira Hosoyama
- NITE Biological Resource Center (NBRC), National Institute of Technology and Evaluation (NITE), Chiba, 292-0818, Japan
| | - Hanako Ataku
- NITE Biological Resource Center (NBRC), National Institute of Technology and Evaluation (NITE), Chiba, 292-0818, Japan
| | - Keiko Nishijima
- NITE Biological Resource Center (NBRC), National Institute of Technology and Evaluation (NITE), Chiba, 292-0818, Japan
| | - Miyako Mise
- NITE Biological Resource Center (NBRC), National Institute of Technology and Evaluation (NITE), Chiba, 292-0818, Japan
| | - Ai Shimizu
- NITE Biological Resource Center (NBRC), National Institute of Technology and Evaluation (NITE), Chiba, 292-0818, Japan
| | - Takeshi Harada
- NITE Biological Resource Center (NBRC), National Institute of Technology and Evaluation (NITE), Chiba, 292-0818, Japan
| | - Hiroshi Horikawa
- NITE Biological Resource Center (NBRC), National Institute of Technology and Evaluation (NITE), Chiba, 292-0818, Japan
| | - Natsuko Ichikawa
- NITE Biological Resource Center (NBRC), National Institute of Technology and Evaluation (NITE), Chiba, 292-0818, Japan
| | - Tomohiro Sekigawa
- NITE Biological Resource Center (NBRC), National Institute of Technology and Evaluation (NITE), Chiba, 292-0818, Japan
| | - Koji Jinno
- NITE Biological Resource Center (NBRC), National Institute of Technology and Evaluation (NITE), Chiba, 292-0818, Japan
| | - Satoshi Tanikawa
- NITE Biological Resource Center (NBRC), National Institute of Technology and Evaluation (NITE), Chiba, 292-0818, Japan
| | - Jun Yamazaki
- NITE Biological Resource Center (NBRC), National Institute of Technology and Evaluation (NITE), Chiba, 292-0818, Japan
| | - Kazumi Sasaki
- NITE Biological Resource Center (NBRC), National Institute of Technology and Evaluation (NITE), Chiba, 292-0818, Japan
| | - Syuji Yamazaki
- NITE Biological Resource Center (NBRC), National Institute of Technology and Evaluation (NITE), Chiba, 292-0818, Japan
| | - Nobuyuki Fujita
- NITE Biological Resource Center (NBRC), National Institute of Technology and Evaluation (NITE), Chiba, 292-0818, Japan
| | - Shigeaki Harayama
- NITE Biological Resource Center (NBRC), National Institute of Technology and Evaluation (NITE), Chiba, 292-0818, Japan.
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Abstract
Archaea are major contributors to biogeochemical cycles, possess unique metabolic capabilities, and resist extreme stress. To regulate the expression of genes encoding these unique programs, archaeal cells use gene regulatory networks (GRNs) composed of transcription factor proteins and their target genes. Recent developments in genetics, genomics, and computational methods used with archaeal model organisms have enabled the mapping and prediction of global GRN structures. Experimental tests of these predictions have revealed the dynamical function of GRNs in response to environmental variation. Here, we review recent progress made in this area, from investigating the mechanisms of transcriptional regulation of individual genes to small-scale subnetworks and genome-wide global networks. At each level, archaeal GRNs consist of a hybrid of bacterial, eukaryotic, and uniquely archaeal mechanisms. We discuss this theme from the perspective of the role of individual transcription factors in genome-wide regulation, how these proteins interact to compile GRN topological structures, and how these topologies lead to emergent, high-level GRN functions. We conclude by discussing how systems biology approaches are a fruitful avenue for addressing remaining challenges, such as discovering gene function and the evolution of GRNs.
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Affiliation(s)
| | - Peter D Tonner
- Department of Biology, Duke University, Durham, North Carolina 27708, USA.,Graduate Program in Computational Biology and Bioinformatics, Duke University, Durham, North Carolina 27708, USA
| | - Cynthia L Darnell
- Department of Biology, Duke University, Durham, North Carolina 27708, USA
| | - Amy K Schmid
- Department of Biology, Duke University, Durham, North Carolina 27708, USA.,Graduate Program in Computational Biology and Bioinformatics, Duke University, Durham, North Carolina 27708, USA.,Center for Genomic and Computational Biology, Duke University, Durham, North Carolina 27708, USA;
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Vishnivetskaya TA, Buongiorno J, Bird J, Krivushin K, Spirina EV, Oshurkova V, Shcherbakova VA, Wilson G, Lloyd KG, Rivkina EM. Methanogens in the Antarctic Dry Valley permafrost. FEMS Microbiol Ecol 2018; 94:5033399. [DOI: 10.1093/femsec/fiy109] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Accepted: 06/01/2018] [Indexed: 11/14/2022] Open
Affiliation(s)
- Tatiana A Vishnivetskaya
- Institute of Physicochemical and Biological Problems in Soil Science, Russian Academy of Sciences, Pushchino, 142290, Russia
- University of Tennessee, Knoxville, TN, 37996, USA
| | | | - Jordan Bird
- University of Tennessee, Knoxville, TN, 37996, USA
| | - Kirill Krivushin
- Institute of Physicochemical and Biological Problems in Soil Science, Russian Academy of Sciences, Pushchino, 142290, Russia
| | - Elena V Spirina
- Institute of Physicochemical and Biological Problems in Soil Science, Russian Academy of Sciences, Pushchino, 142290, Russia
| | - Victoria Oshurkova
- Institute of Physicochemical and Biological Problems in Soil Science, Russian Academy of Sciences, Pushchino, 142290, Russia
- Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino, 142290, Russia
| | - Victoria A Shcherbakova
- Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino, 142290, Russia
| | - Gary Wilson
- University of Otago, Dunedin, 9054, New Zealand
| | | | - Elizaveta M Rivkina
- Institute of Physicochemical and Biological Problems in Soil Science, Russian Academy of Sciences, Pushchino, 142290, Russia
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26
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Hodge-Hanson KM, Zoino A, Downs DM. Expression of Pyridoxal 5'-Phosphate-Independent Racemases Can Reduce 2-Aminoacrylate Stress in Salmonella enterica. J Bacteriol 2018; 200:e00751-17. [PMID: 29440254 DOI: 10.1128/JB.00751-17] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 02/09/2018] [Indexed: 11/20/2022] Open
Abstract
The RidA protein (PF01042) from Salmonella enterica is a deaminase that quenches 2-aminoacrylate (2AA) and other reactive metabolites. In the absence of RidA, 2AA accumulates, damages cellular enzymes, and compromises the metabolic network. In vitro, RidA homologs from all domains of life deaminate 2AA, and RidA proteins from plants, bacteria, yeast, and humans complement the mutant phenotype of a ridA mutant strain of S. enterica In the present study, a methanogenic archaeon, Methanococcus maripaludis S2, was used to probe alternative mechanisms to restore metabolic balance. M. maripaludis MMP0739, which is annotated as an aspartate/glutamate racemase, complemented a ridA mutant strain and reduced the intracellular 2AA burden. The aspartate/glutamate racemase YgeA from Escherichia coli or S. enterica, when provided in trans, similarly restored wild-type growth to a ridA mutant. These results uncovered a new mechanism to ameliorate metabolic stress, and they suggest that direct quenching by RidA is not the only strategy to quench 2AA.IMPORTANCE 2-Aminoacrylate is an endogenously generated reactive metabolite that can damage cellular enzymes if not directly quenched by the conserved deaminase RidA. This study used an archaeon to identify a RidA-independent mechanism to prevent metabolic stress caused by 2AA. The data suggest that a gene product annotated as an aspartate/glutamate racemase (MMP0739) produces a metabolite that can quench 2AA, expanding our understanding of strategies available to quench reactive metabolites.
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Poehlein A, Heym D, Quitzke V, Fersch J, Daniel R, Rother M. Complete Genome Sequence of the Methanococcus maripaludis Type Strain JJ (DSM 2067), a Model for Selenoprotein Synthesis in Archaea. Genome Announc 2018; 6:e00237-18. [PMID: 29622618 DOI: 10.1128/genomeA.00237-18] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Methanococcus maripaludis type strain JJ (DSM 2067) is an important organism because it serves as a model for primary energy metabolism and hydrogenotrophic methanogenesis and is amenable to genetic manipulation. The complete genome (1.7 Mb) harbors 1,815 predicted protein-encoding genes, including 9 encoding selenoproteins.
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Lienemann M, Deutzmann JS, Milton RD, Sahin M, Spormann AM. Mediator-free enzymatic electrosynthesis of formate by the Methanococcus maripaludis heterodisulfide reductase supercomplex. Bioresour Technol 2018; 254:278-283. [PMID: 29413934 DOI: 10.1016/j.biortech.2018.01.036] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 01/05/2018] [Accepted: 01/06/2018] [Indexed: 06/08/2023]
Abstract
Electrosynthesis of formate is a promising technology to convert CO2 and electricity from renewable sources into a biocompatible, soluble, non-flammable, and easily storable compound. In the model methanogen Methanococcus maripaludis, uptake of cathodic electrons was shown to proceed indirectly via formation of formate or H2 by undefined, cell-derived enzymes. Here, we identified that the multi-enzyme heterodisulfide reductase supercomplex (Hdr-SC) of M. maripaludis is capable of direct electron uptake and catalyzes rapid H2 and formate formation in electrochemical reactors (-800 mV vs Ag/AgCl) and in Fe(0) corrosion assays. In Fe(0) corrosion assays and electrochemical reactors, purified Hdr-SC primarily catalyzed CO2 reduction to formate with a coulombic efficiency of 90% in the electrochemical cells for 5 days. Thus, this report identified the first enzyme that stably catalyzes the mediator-free electrochemical reduction of CO2 to formate, which can serve as the basis of an enzyme electrode for sustained electrochemical production of formate.
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Affiliation(s)
- Michael Lienemann
- VTT Technical Research Centre of Finland Ltd, Espoo 02150, Finland; Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305, USA
| | - Jörg Stefan Deutzmann
- Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305, USA
| | - Ross Dean Milton
- Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305, USA
| | - Merve Sahin
- Tri-Institutional Training Program in Computational Biology and Medicine, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Alfred Michael Spormann
- Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305, USA; Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA.
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Lyu Z, Chou CW, Shi H, Wang L, Ghebreab R, Phillips D, Yan Y, Duin EC, Whitman WB. Assembly of Methyl Coenzyme M Reductase in the Methanogenic Archaeon Methanococcus maripaludis. J Bacteriol 2018; 200:e00746-17. [PMID: 29339414 DOI: 10.1128/JB.00746-17] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2017] [Accepted: 01/04/2018] [Indexed: 01/22/2023] Open
Abstract
Methyl coenzyme M reductase (MCR) is a complex enzyme that catalyzes the final step in biological methanogenesis. To better understand its assembly, the recombinant MCR from the thermophile Methanothermococcus okinawensis (rMCRok) was expressed in the mesophile Methanococcus maripaludis The rMCRok was posttranslationally modified correctly and contained McrD and the unique nickel tetrapyrrole coenzyme F430 Subunits of the native M. maripaludis (MCRmar) were largely absent, suggesting that the recombinant enzyme was formed by an assembly of cotranscribed subunits. Strong support for this hypothesis was obtained by expressing a chimeric operon comprising the His-tagged mcrA from M. maripaludis and the mcrBDCG from M. okinawensis in M. maripaludis The His-tagged purified rMCR then contained the M. maripaludis McrA and the M. okinawensis McrBDG. The present study prompted us to form a working model for MCR assembly, which can be further tested by the heterologous expression system established here.IMPORTANCE Approximately 1.6% of the net primary production of plants, algae, and cyanobacteria are processed by biological methane production in anoxic environments. This accounts for about 74% of the total global methane production, up to 25% of which is consumed by anaerobic oxidation of methane (AOM). Methyl coenzyme M reductase (MCR) is the key enzyme in both methanogenesis and AOM. MCR is assembled as a dimer of two heterotrimers, where posttranslational modifications and F430 cofactors are embedded in the active sites. However, this complex assembly process remains unknown. Here, we established a heterologous expression system for MCR to learn how MCR is assembled.
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Abdel Azim A, Rittmann SKMR, Fino D, Bochmann G. The physiological effect of heavy metals and volatile fatty acids on Methanococcus maripaludis S2. Biotechnol Biofuels 2018; 11:301. [PMID: 30410576 PMCID: PMC6214177 DOI: 10.1186/s13068-018-1302-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 10/25/2018] [Indexed: 05/16/2023]
Abstract
BACKGROUND Methanogenic archaea are of importance to the global C-cycle and to biological methane (CH4) production through anaerobic digestion and pure culture. Here, the individual and combined effects of copper (Cu), zinc (Zn), acetate, and propionate on the metabolism of the autotrophic, hydrogenotrophic methanogen Methanococcus maripaludis S2 were investigated. Cu, Zn, acetate, and propionate may interfere directly and indirectly with the acetyl-CoA synthesis and biological CH4 production. Thus, these compounds can compromise or improve the performance of M. maripaludis, an organism which can be applied as biocatalyst in the carbon dioxide (CO2)-based biological CH4 production (CO2-BMP) process or of methanogenic organisms applied in anaerobic digestion. RESULTS Here, we show that Cu concentration of 1.9 µmol L-1 reduced growth of M. maripaludis, whereas 4.4 and 6.3 µmol L-1 of Cu even further retarded biomass production. However, 1.0 mmol L-1 of Zn enhanced growth, but at Zn concentrations > 2.4 mmol L-1 no growth could be observed. When both, Cu and Zn, were supplemented to the medium, growth and CH4 production could even be observed at the highest tested concentration of Cu (6.3 µmol L-1). Hence, it seems that the addition of 1 mmol L-1 of Zn enhanced the ability of M. maripaludis to counteract the toxic effect of Cu. The physiological effect to rising concentrations of acetate (12.2, 60.9, 121.9 mmol L-1) and/or propionate (10.3, 52.0, 104.1 mmol L-1) was also investigated. When instead of acetate 10.3 mmol L-1 propionate was provided in the growth medium, M. maripaludis could grow without reduction of the specific growth rate (µ) or the specific CH4 productivity (qCH4). A combination of inorganic and/or organic compounds resulted in an increase of µ and qCH4 for Zn/Cu and Zn/acetate beyond the values that were observed if only the individual concentrations of Zn, Cu, acetate were used. CONCLUSIONS Our study sheds light on the physiological effect of VFAs and heavy metals on M. maripaludis. Differently from µ and qCH4, MER was not influenced by the presence of these compounds. This indicated that each of these compounds directly interacted with the C-fixation machinery of M. maripaludis. Until now, the uptake of VFAs other than acetate was not considered to enhance growth and CH4 production of methanogens. The finding of propionate uptake by M. maripaludis is important for the interpretation of VFA cycling in anaerobic microenvironments. Due to the importance of methanogens in natural and artificial anaerobic environments, our results help to enhance the understanding the physiological and biotechnological importance with respect to anaerobic digestion, anaerobic wastewater treatment, and CO2-BMP. Finally, we propose a possible mechanism for acetate uptake into M. maripaludis supported by in silico analyses.
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Affiliation(s)
- Annalisa Abdel Azim
- Institute for Environmental Biotechnology, IFA Department Tulln, University of Natural Resources and Life Sciences, Vienna, Austria
- Archaea Physiology & Biotechnology Group, Archaea Biology and Ecogenomics Division, Department of Ecogenomics and Systems Biology, Universität Wien, Althanstraße 14, 1090 Vienna, Austria
- Department of Applied Science and Technology (DISAT), Politecnico di Torino, Turin, Italy
- Center for Sustainable Future Technologies, Istituto Italiano di Tecnologia, Turin, Italy
| | - Simon K.-M. R. Rittmann
- Archaea Physiology & Biotechnology Group, Archaea Biology and Ecogenomics Division, Department of Ecogenomics and Systems Biology, Universität Wien, Althanstraße 14, 1090 Vienna, Austria
| | - Debora Fino
- Department of Applied Science and Technology (DISAT), Politecnico di Torino, Turin, Italy
| | - Günther Bochmann
- Institute for Environmental Biotechnology, IFA Department Tulln, University of Natural Resources and Life Sciences, Vienna, Austria
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Weimar MR, Cheung J, Dey D, McSweeney C, Morrison M, Kobayashi Y, Whitman WB, Carbone V, Schofield LR, Ronimus RS, Cook GM. Development of Multiwell-Plate Methods Using Pure Cultures of Methanogens To Identify New Inhibitors for Suppressing Ruminant Methane Emissions. Appl Environ Microbiol 2017; 83:e00396-17. [PMID: 28526787 DOI: 10.1128/AEM.00396-17] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 05/09/2017] [Indexed: 12/30/2022] Open
Abstract
Hydrogenotrophic methanogens typically require strictly anaerobic culturing conditions in glass tubes with overpressures of H2 and CO2 that are both time-consuming and costly. To increase the throughput for screening chemical compound libraries, 96-well microtiter plate methods for the growth of a marine (environmental) methanogen Methanococcus maripaludis strain S2 and the rumen methanogen Methanobrevibacter species AbM4 were developed. A number of key parameters (inoculum size, reducing agents for medium preparation, assay duration, inhibitor solvents, and culture volume) were optimized to achieve robust and reproducible growth in a high-throughput microtiter plate format. The method was validated using published methanogen inhibitors and statistically assessed for sensitivity and reproducibility. The Sigma-Aldrich LOPAC library containing 1,280 pharmacologically active compounds and an in-house natural product library (120 compounds) were screened against M. maripaludis as a proof of utility. This screen identified a number of bioactive compounds, and MIC values were confirmed for some of them against M. maripaludis and M. AbM4. The developed method provides a significant increase in throughput for screening compound libraries and can now be used to screen larger compound libraries to discover novel methanogen-specific inhibitors for the mitigation of ruminant methane emissions.IMPORTANCE Methane emissions from ruminants are a significant contributor to global greenhouse gas emissions, and new technologies are required to control emissions in the agriculture technology (agritech) sector. The discovery of small-molecule inhibitors of methanogens using high-throughput phenotypic (growth) screening against compound libraries (synthetic and natural products) is an attractive avenue. However, phenotypic inhibitor screening is currently hindered by our inability to grow methanogens in a high-throughput format. We have developed, optimized, and validated a high-throughput 96-well microtiter plate assay for growing environmental and rumen methanogens. Using this platform, we identified several new inhibitors of methanogen growth, demonstrating the utility of this approach to fast track the development of methanogen-specific inhibitors for controlling ruminant methane emissions.
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Walters AD, Chong JPJ. Non-essential MCM-related proteins mediate a response to DNA damage in the archaeon Methanococcus maripaludis. Microbiology (Reading) 2017; 163:745-753. [PMID: 28516862 DOI: 10.1099/mic.0.000460] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The single minichromosome maintenance (MCM) protein found in most archaea has been widely studied as a simplified model for the MCM complex that forms the catalytic core of the eukaryotic replicative helicase. Organisms of the order Methanococcales are unusual in possessing multiple MCM homologues. The Methanococcus maripaludis S2 genome encodes four MCM homologues, McmA-McmD. DNA helicase assays reveal that the unwinding activity of the three MCM-like proteins is highly variable despite sequence similarities and suggests additional motifs that influence MCM function are yet to be identified. While the gene encoding McmA could not be deleted, strains harbouring individual deletions of genes encoding each of the other MCMs display phenotypes consistent with these proteins modulating DNA damage responses. M. maripaludis S2 is the first archaeon in which MCM proteins have been shown to influence the DNA damage response.
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Affiliation(s)
- Alison D Walters
- Department of Biology (Area 5), University of York, Wentworth Way, Heslington, York, YO10 5DD, UK.,Present address: NIH/NIDDK, 8 Center Drive, Bethesda, 20892 MD, USA
| | - James P J Chong
- Department of Biology (Area 5), University of York, Wentworth Way, Heslington, York, YO10 5DD, UK
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Conway de Macario E, Robb FT, Macario AJL. Prokaryotic Chaperonins as Experimental Models for Elucidating Structure-Function Abnormalities of Human Pathogenic Mutant Counterparts. Front Mol Biosci 2017; 3:84. [PMID: 28119916 PMCID: PMC5220055 DOI: 10.3389/fmolb.2016.00084] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 12/12/2016] [Indexed: 01/29/2023] Open
Abstract
All archaea have a chaperonin of Group II (thermosome) in their cytoplasm and some have also a chaperonin of Group I (GroEL; Cpn60; Hsp60). Conversely, all bacteria have GroEL, some in various copies, but only a few have, in addition, a chaperonin (tentatively designated Group III chaperonin) very similar to that occurring in all archaea, i.e., the thermosome subunit, and in the cytosol of eukaryotic cells, named CCT. Thus, nature offers a range of prokaryotic organisms that are potentially useful as experimental models to study the human CCT and its abnormalities. This is important because many diseases, the chaperonopathies, have been identified in which abnormal chaperones, including mutant CCT, are determinant etiologic-pathogenic factors and, therefore, research is needed to elucidate their pathologic features at the molecular level. Such research should lead to the clarification of the molecular mechanisms underlying the pathologic lesions observed in the tissues and organs of patients with chaperonopathies. Information on these key issues is necessary to make progress in diagnosis and treatment. Some of the archaeal organisms as well as some of the bacterial models suitable for studying molecular aspects pertinent to human mutant chaperones are discussed here, focusing on CCT. Results obtained with the archaeon Pyrococcus furiosus model to investigate the impact of a pathogenic CCT5 mutation on molecular properties and chaperoning functions are reviewed. The pathogenic mutation examined weakens the ability of the chaperonin subunit to form stable hexadecamers and as a consequence, the chaperoning functions of the complex are impaired. The future prospect is to find means for stabilizing the hexadecamer, which should lead to a recovering of chaperone function and the improving of lesions and clinical condition.
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Affiliation(s)
- Everly Conway de Macario
- Department of Microbiology and Immunology, School of Medicine, University of Maryland at Baltimore, Columbus Center; Institute of Marine and Environmental TechnologyBaltimore, MD, USA; Euro-Mediterranean Institute of Science and TechnologyPalermo, Italy
| | - Frank T Robb
- Department of Microbiology and Immunology, School of Medicine, University of Maryland at Baltimore, Columbus Center; Institute of Marine and Environmental TechnologyBaltimore, MD, USA; Institute for Bioscience and Biotechnology Research, University of Maryland, College ParkRockville, MD, USA
| | - Alberto J L Macario
- Department of Microbiology and Immunology, School of Medicine, University of Maryland at Baltimore, Columbus Center; Institute of Marine and Environmental TechnologyBaltimore, MD, USA; Euro-Mediterranean Institute of Science and TechnologyPalermo, Italy
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Richards MA, Lie TJ, Zhang J, Ragsdale SW, Leigh JA, Price ND. Exploring Hydrogenotrophic Methanogenesis: a Genome Scale Metabolic Reconstruction of Methanococcus maripaludis. J Bacteriol 2016; 198:3379-90. [PMID: 27736793 DOI: 10.1128/JB.00571-16] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 09/22/2016] [Indexed: 02/03/2023] Open
Abstract
Hydrogenotrophic methanogenesis occurs in multiple environments, ranging from the intestinal tracts of animals to anaerobic sediments and hot springs. Energy conservation in hydrogenotrophic methanogens was long a mystery; only within the last decade was it reported that net energy conservation for growth depends on electron bifurcation. In this work, we focus on Methanococcus maripaludis, a well-studied hydrogenotrophic marine methanogen. To better understand hydrogenotrophic methanogenesis and compare it with methylotrophic methanogenesis that utilizes oxidative phosphorylation rather than electron bifurcation, we have built iMR539, a genome scale metabolic reconstruction that accounts for 539 of the 1,722 protein-coding genes of M. maripaludis strain S2. Our reconstructed metabolic network uses recent literature to not only represent the central electron bifurcation reaction but also incorporate vital biosynthesis and assimilation pathways, including unique cofactor and coenzyme syntheses. We show that our model accurately predicts experimental growth and gene knockout data, with 93% accuracy and a Matthews correlation coefficient of 0.78. Furthermore, we use our metabolic network reconstruction to probe the implications of electron bifurcation by showing its essentiality, as well as investigating the infeasibility of aceticlastic methanogenesis in the network. Additionally, we demonstrate a method of applying thermodynamic constraints to a metabolic model to quickly estimate overall free-energy changes between what comes in and out of the cell. Finally, we describe a novel reconstruction-specific computational toolbox we created to improve usability. Together, our results provide a computational network for exploring hydrogenotrophic methanogenesis and confirm the importance of electron bifurcation in this process. IMPORTANCE Understanding and applying hydrogenotrophic methanogenesis is a promising avenue for developing new bioenergy technologies around methane gas. Although a significant portion of biological methane is generated through this environmentally ubiquitous pathway, existing methanogen models portray the more traditional energy conservation mechanisms that are found in other methanogens. We have constructed a genome scale metabolic network of Methanococcus maripaludis that explicitly accounts for all major reactions involved in hydrogenotrophic methanogenesis. Our reconstruction demonstrates the importance of electron bifurcation in central metabolism, providing both a window into hydrogenotrophic methanogenesis and a hypothesis-generating platform to fuel metabolic engineering efforts.
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Ding Y, Nash J, Berezuk A, Khursigara CM, Langelaan DN, Smith SP, Jarrell KF. Identification of the first transcriptional activator of an archaellum operon in a euryarchaeon. Mol Microbiol 2016; 102:54-70. [PMID: 27314758 DOI: 10.1111/mmi.13444] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/16/2016] [Indexed: 12/21/2022]
Abstract
The archaellum is the swimming organelle of the third domain, the Archaea. In the euryarchaeon Methanococcus maripaludis, genes involved in archaella formation, including the three archaellins flaB1, flaB2 and flaB3, are mainly located in the fla operon. Previous studies have shown that transcription of fla genes and expression of Fla proteins are regulated under different growth conditions. In this study, we identify MMP1718 as the first transcriptional activator that directly regulates the fla operon in M. maripaludis. Mutants carrying an in-frame deletion in mmp1718 did not express FlaB2 detected by western blotting. Quantitative reverse transcription PCR analysis of purified RNA from the Δmmp1718 mutant showed that transcription of flaB2 was negligible compared to wildtype cells. In addition, no archaella were observed on the cell surface of the Δmmp1718 mutant. FlaB2 expression and archaellation were restored when the Δmmp1718 mutant was complemented with mmp1718 in trans. Electrophoretic motility shift assay and isothermal titration calorimetry results demonstrated the specific binding of purified MMP1718 to DNA fragments upstream of the fla promoter. Four 6 bp consensus sequences were found immediately upstream of the fla promoter and are considered the putative MMP1718-binding sites. Herein, we designate MMP1718 as EarA, the first euryarchaeal archaellum regulator.
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Affiliation(s)
- Yan Ding
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, K7L 3N6, Canada
| | - John Nash
- Laboratory for Foodborne Zoonoses, Public Health Agency of Canada, Guelph, Ontario, N1G 3W4, Canada
| | - Alison Berezuk
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
| | - Cezar M Khursigara
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
| | - David N Langelaan
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, K7L 3N6, Canada
| | - Steven P Smith
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, K7L 3N6, Canada
| | - Ken F Jarrell
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, K7L 3N6, Canada.
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Abstract
The rapid autotrophic growth of the methanogenic archaeon Methanococcus maripaludis on H2 and CO2 makes it an attractive microbial chassis to inexpensively produce biochemicals. To explore this potential, a synthetic gene encoding geraniol synthase (GES) derived from Ocimum basilicum was cloned into a M. maripaludis expression vector under selection for puromycin resistance. Recombinant expression of GES in M. maripaludis during autotrophic growth on H2/CO2 or formate yielded geraniol at 2.8 and 4.0 mg g(-1) of dry weight, respectively. The yield of geraniol decreased 2-3-fold when organic carbon sources were added to stimulate heterotrophic growth. In the absence of puromycin, geraniol production during autotrophic growth on formate increased to 4.6 mg g(-1) of dry weight. A conceptual model centered on the autotrophic acetyl coenzyme A biosynthetic pathway identified strategies to divert more autotrophic carbon flux to geraniol production.
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Affiliation(s)
- Zhe Lyu
- Department of Microbiology, ‡College of Engineering, and §Department of Biochemistry and Molecular
Biology, University of Georgia, Athens, Georgia 30602, United States
| | - Rachit Jain
- Department of Microbiology, ‡College of Engineering, and §Department of Biochemistry and Molecular
Biology, University of Georgia, Athens, Georgia 30602, United States
| | - Peyton Smith
- Department of Microbiology, ‡College of Engineering, and §Department of Biochemistry and Molecular
Biology, University of Georgia, Athens, Georgia 30602, United States
| | - Travis Fetchko
- Department of Microbiology, ‡College of Engineering, and §Department of Biochemistry and Molecular
Biology, University of Georgia, Athens, Georgia 30602, United States
| | - Yajun Yan
- Department of Microbiology, ‡College of Engineering, and §Department of Biochemistry and Molecular
Biology, University of Georgia, Athens, Georgia 30602, United States
| | - William B. Whitman
- Department of Microbiology, ‡College of Engineering, and §Department of Biochemistry and Molecular
Biology, University of Georgia, Athens, Georgia 30602, United States
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Abstract
Methanococcus maripaludis is a rapidly growing, fully sequenced, genetically tractable model organism among hydrogenotrophic methanogens. It has the ability to convert CO2 and H2 into a useful cleaner energy fuel (CH4). In fact, this conversion enhances in the presence of free nitrogen as the sole nitrogen source due to prolonged cell growth. Given the global importance of GHG emissions and climate change, diazotrophy can be attractive for carbon capture and utilization applications from appropriately treated flue gases, where surplus hydrogen is available from renewable electricity sources. In addition, M. maripaludis can be engineered to produce other useful products such as terpenoids, hydrogen, methanol, etc. M. maripaludis with its unique abilities has the potential to be a workhorse like Escherichia coli and S. cerevisiae for fundamental and experimental biotechnology studies. More than 100 experimental studies have explored different specific aspects of the biochemistry and genetics of CO2 and N2 fixation by M. maripaludis. Its genome-scale metabolic model (iMM518) also exists to study genetic perturbations and complex biological interactions. However, a comprehensive review describing its cell structure, metabolic processes, and methanogenesis is still lacking in the literature. This review fills this crucial gap. Specifically, it integrates distributed information from the literature to provide a complete and detailed view for metabolic processes such as acetyl-CoA synthesis, pyruvate synthesis, glycolysis/gluconeogenesis, reductive tricarboxylic acid (RTCA) cycle, non-oxidative pentose phosphate pathway (NOPPP), nitrogen metabolism, amino acid metabolism, and nucleotide biosynthesis. It discusses energy production via methanogenesis and its relation to metabolism. Furthermore, it reviews taxonomy, cell structure, culture/storage conditions, molecular biology tools, genome-scale models, and potential industrial and environmental applications. Through the discussion, it develops new insights and hypotheses from experimental and modeling observations, and identifies opportunities for further research and applications.
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Affiliation(s)
- Nishu Goyal
- />Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore, 117585 Singapore
| | - Zhi Zhou
- />School of Civil Engineering and Division of Environmental and Ecological Engineering, Purdue University, 550 Stadium Mall Drive, West Lafayette, IN 47907 USA
| | - Iftekhar A. Karimi
- />Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore, 117585 Singapore
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Greening C, Ahmed FH, Mohamed AE, Lee BM, Pandey G, Warden AC, Scott C, Oakeshott JG, Taylor MC, Jackson CJ. Physiology, Biochemistry, and Applications of F420- and Fo-Dependent Redox Reactions. Microbiol Mol Biol Rev 2016; 80:451-93. [PMID: 27122598 DOI: 10.1128/MMBR.00070-15] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
5-Deazaflavin cofactors enhance the metabolic flexibility of microorganisms by catalyzing a wide range of challenging enzymatic redox reactions. While structurally similar to riboflavin, 5-deazaflavins have distinctive and biologically useful electrochemical and photochemical properties as a result of the substitution of N-5 of the isoalloxazine ring for a carbon. 8-Hydroxy-5-deazaflavin (Fo) appears to be used for a single function: as a light-harvesting chromophore for DNA photolyases across the three domains of life. In contrast, its oligoglutamyl derivative F420 is a taxonomically restricted but functionally versatile cofactor that facilitates many low-potential two-electron redox reactions. It serves as an essential catabolic cofactor in methanogenic, sulfate-reducing, and likely methanotrophic archaea. It also transforms a wide range of exogenous substrates and endogenous metabolites in aerobic actinobacteria, for example mycobacteria and streptomycetes. In this review, we discuss the physiological roles of F420 in microorganisms and the biochemistry of the various oxidoreductases that mediate these roles. Particular focus is placed on the central roles of F420 in methanogenic archaea in processes such as substrate oxidation, C1 pathways, respiration, and oxygen detoxification. We also describe how two F420-dependent oxidoreductase superfamilies mediate many environmentally and medically important reactions in bacteria, including biosynthesis of tetracycline and pyrrolobenzodiazepine antibiotics by streptomycetes, activation of the prodrugs pretomanid and delamanid by Mycobacterium tuberculosis, and degradation of environmental contaminants such as picrate, aflatoxin, and malachite green. The biosynthesis pathways of Fo and F420 are also detailed. We conclude by considering opportunities to exploit deazaflavin-dependent processes in tuberculosis treatment, methane mitigation, bioremediation, and industrial biocatalysis.
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Seyhan D, Jehmlich N, von Bergen M, Fersch J, Rother M. Selenocysteine-independent suppression of UGA codons in the archaeon Methanococcus maripaludis. Biochim Biophys Acta Gen Subj 2015. [PMID: 26215786 DOI: 10.1016/j.bbagen.2015.07.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
BACKGROUND Proteins containing selenocysteine (sec) are found in Bacteria, Eukarya, and Archaea. While selenium-dependence of methanogenesis from H(2)+CO(2) in the archaeon Methanococcus maripaludis JJ is compensated by induction of a set of cysteine-containing homologs, growth on formate is abrogated in the absence of sec due to the dependence of formate dehydrogenase (Fdh) on selenium. Despite this dependence, formate-dependent growth occurs after prolonged incubation of M. maripaludis mutants lacking sec. METHODS To study this phenomenon, a M. maripaludis strain with only one Fdh isoform and an FdhA selenoprotein C-terminally tagged for affinity enrichment was constructed. Factors required for sec synthesis were deleted in this strain and translation of UGA in fdhA was analyzed physiologically, enzymatically, immunologically, and via mass spectrometry. RESULTS M. maripaludis JJ mutants lacking sec synthesis grew at least five times more slowly than the wild type on formate due to a 20-35-fold reduction of Fdh activity. The enzyme in the mutant strains lacked sec but was still produced as a full-length protein. Peptide mass spectrometry revealed that both cysteine (cys) and tryptophan (trp) were inserted at the UGA encoding sec without apparent mutations in tRNA(cys) or tRNA(trp), respectively. CONCLUSIONS We demonstrate that M. maripaludis has the inherent capacity to translate UGA with cys and trp; other mechanisms to replace sec with cys in the absence of selenium could thereby be ruled out. GENERAL SIGNIFICANCE This study exemplifies how an organism uses the inherent flexibility in its canonical protein synthesis machinery to recover some activity of an essential selenium-dependent enzyme in the absence of sec.
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Affiliation(s)
- Deniz Seyhan
- Institute of Molecular Biosciences, Johann Wolfgang Goethe Universität Frankfurt, Marie-Curie-Str. 9, 60439 Frankfurt am Main, Germany
| | - Nico Jehmlich
- Department of Proteomics, Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig, Germany
| | - Martin von Bergen
- Department of Proteomics, Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig, Germany; Department of Metabolomics, Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig, Germany; Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7, 9220 Aalborg, Denmark
| | - Julia Fersch
- Institute of Microbiology, Technische Universität Dresden, 01062 Dresden, Germany
| | - Michael Rother
- Institute of Molecular Biosciences, Johann Wolfgang Goethe Universität Frankfurt, Marie-Curie-Str. 9, 60439 Frankfurt am Main, Germany; Institute of Microbiology, Technische Universität Dresden, 01062 Dresden, Germany.
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Lyu Z, Lu Y. Comparative genomics of three Methanocellales strains reveal novel taxonomic and metabolic features. Environ Microbiol Rep 2015; 7:526-537. [PMID: 25727385 DOI: 10.1111/1758-2229.12283] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Accepted: 02/22/2015] [Indexed: 06/04/2023]
Abstract
Methanocellales represents a new order of methanogens, which is widespread in environments and plays specifically the important role in methane emissions from paddy fields. To gain more insights into Methanocellales, comparative genomic studies were performed among three Methanocellales strains through the same annotation pipeline. Genetic relationships among strains revealed by genome alignment, pan-genome reconstruction and comparison of amino average identity suggest that they should be classified in different genera. In addition, multiple copies of cell cycle regulator proteins were identified for the first time in Archaea. Core metabolisms were reconstructed, predicting certain unique and novel features for Methanocellales, including a set of methanogenesis genes potentially organized toward specialization in utilizing low concentrations of H2, a new route of disulfide reduction catalysed by a disulfide-reducing hydrogenase (Drh) complex phylogenetically related to sulfate-reducing prokaryotes, an oxidative tricarboxylic acid (TCA) cycle, a sophisticated nitrogen uptake and regulation system as well as a versatile sulfur utilization system. These core metabolisms are largely conserved among the three strains, but differences in gene copy number and metabolic diversity are evident. The present study thus adds new dimensions to the unique ecophysiology of Methanocellales and offers a road map for further experimental characterization of this methanogen lineage.
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Affiliation(s)
- Zhe Lyu
- College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China
| | - Yahai Lu
- College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China
- College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China
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Abstract
Type IV pili are ancient proteinaceous structures present on the cell surface of species in nearly all bacterial and archaeal phyla. These filaments, which are required for a diverse array of important cellular processes, are assembled employing a conserved set of core components. While type IV pilins, the structural subunits of pili, share little sequence homology, their signal peptides are structurally conserved allowing for in silico prediction. Recently, in vivo studies in model archaea representing the euryarchaeal and crenarchaeal kingdoms confirmed that several of these pilins are incorporated into type IV adhesion pili. In addition to facilitating surface adhesion, these in vivo studies also showed that several predicted pilins are required for additional functions that are critical to biofilm formation. Examples include the subunits of Sulfolobus acidocaldarius Ups pili, which are induced by exposure to UV light and promote cell aggregation and conjugation, and a subset of the Haloferax volcanii adhesion pilins, which play a critical role in microcolony formation while other pilins inhibit this process. The recent discovery of novel pilin functions such as the ability of haloarchaeal adhesion pilins to regulate swimming motility may point to novel regulatory pathways conserved across prokaryotic domains. In this review, we will discuss recent advances in our understanding of the functional roles played by archaeal type IV adhesion pili and their subunits, with particular emphasis on their involvement in biofilm formation.
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Affiliation(s)
| | - Rianne N Esquivel
- Department of Biology, University of Pennsylvania Philadelphia, PA, USA
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Siu S, Robotham A, Logan SM, Kelly JF, Uchida K, Aizawa S, Jarrell KF. Evidence that biosynthesis of the second and third sugars of the archaellin Tetrasaccharide in the archaeon Methanococcus maripaludis occurs by the same pathway used by Pseudomonas aeruginosa to make a di-N-acetylated sugar. J Bacteriol 2015; 197:1668-80. [PMID: 25733616 DOI: 10.1128/JB.00040-15] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 02/24/2015] [Indexed: 01/09/2023] Open
Abstract
UNLABELLED Methanococcus maripaludis has two surface appendages, archaella and type IV pili, which are composed of glycoprotein subunits. Archaellins are modified with an N-linked tetrasaccharide with the structure Sug-1,4-β-ManNAc3NAmA6Thr-1,4-β-GlcNAc3NAcA-1,3-β-GalNAc, where Sug is (5S)-2-acetamido-2,4-dideoxy-5-O-methyl-α-L-erythro-hexos-5-ulo-1,5-pyranose. The pilin glycan has an additional hexose attached to GalNAc. In this study, genes located in two adjacent, divergently transcribed operons (mmp0350-mmp0354 and mmp0359-mmp0355) were targeted for study based on annotations suggesting their involvement in biosynthesis of N-glycan sugars. Mutants carrying deletions in mmp0350, mmp0351, mmp0352, or mmp0353 were nonarchaellated and synthesized archaellins modified with a 1-sugar glycan, as estimated from Western blots. Mass spectroscopy analysis of pili purified from the Δmmp0352 strain confirmed a glycan with only GalNAc, suggesting mmp0350 to mmp0353 were all involved in biosynthesis of the second sugar (GlcNAc3NAcA). The Δmmp0357 mutant was archaellated and had archaellins with a 2-sugar glycan, as confirmed by mass spectroscopy of purified archaella, indicating a role for MMP0357 in biosynthesis of the third sugar (ManNAc3NAmA6Thr). M. maripaludis mmp0350, mmp0351, mmp0352, mmp0353, and mmp0357 are proposed to be functionally equivalent to Pseudomonas aeruginosa wbpABEDI, involved in converting UDP-N-acetylglucosamine to UDP-2,3-diacetamido-2,3-dideoxy-d-mannuronic acid, an O5-specific antigen sugar. Cross-domain complementation of the final step of the P. aeruginosa pathway with mmp0357 supports this hypothesis. IMPORTANCE This work identifies a series of genes in adjacent operons that are shown to encode the enzymes that complete the entire pathway for generation of the second and third sugars of the N-linked tetrasaccharide that modifies archaellins of Methanococcus maripaludis. This posttranslational modification of archaellins is important, as it is necessary for archaellum assembly. Pilins are modified with a different N-glycan consisting of the archaellin tetrasaccharide but with an additional hexose attached to the linking sugar. Mass spectrometry analysis of the pili of one mutant strain provided insight into how this different glycan might ultimately be assembled. This study includes a rare example of an archaeal gene functionally replacing a bacterial gene in a complex sugar biosynthesis pathway.
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Nair DB, Jarrell KF. Pilin Processing Follows a Different Temporal Route than That of Archaellins in Methanococcus maripaludis. Life (Basel) 2015; 5:85-101. [PMID: 25569238 PMCID: PMC4390842 DOI: 10.3390/life5010085] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 12/26/2014] [Indexed: 11/16/2022] Open
Abstract
Methanococcus maripaludis has two different surface appendages: type IV-like pili and archaella. Both structures are believed to be assembled using a bacterial type IV pilus mechanism. Each structure is composed of multiple subunits, either pilins or archaellins. Both pilins and archaellins are made initially as preproteins with type IV pilin-like signal peptides, which must be removed by a prepilin peptidase-like enzyme. This enzyme is FlaK for archaellins and EppA for pilins. In addition, both pilins and archaellins are modified with N-linked glycans. The archaellins possess an N-linked tetrasaccharide while the pilins have a pentasaccharide which consists of the archaellin tetrasaccharide but with an additional sugar, an unidentified hexose, attached to the linking sugar. In this report, we show that archaellins can be processed by FlaK in the absence of N-glycosylation and N-glycosylation can occur on archaellins that still retain their signal peptides. In contrast, pilins are not glycosylated unless they have been acted on by EppA to have the signal peptide removed. However, EppA can still remove signal peptides from non-glycosylated pilins. These findings indicate that there is a difference in the order of the posttranslational modifications of pilins and archaellins even though both are type IV pilin-like proteins.
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Affiliation(s)
- Divya B Nair
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON K7L 3N6, Canada.
| | - Ken F Jarrell
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON K7L 3N6, Canada.
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Hartmann T, Schwanhold N, Leimkühler S. Assembly and catalysis of molybdenum or tungsten-containing formate dehydrogenases from bacteria. Biochim Biophys Acta 2014; 1854:1090-100. [PMID: 25514355 DOI: 10.1016/j.bbapap.2014.12.006] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 12/04/2014] [Accepted: 12/06/2014] [Indexed: 11/28/2022]
Abstract
The global carbon cycle depends on the biological transformations of C1 compounds, which include the reductive incorporation of CO₂into organic molecules (e.g. in photosynthesis and other autotrophic pathways), in addition to the production of CO₂from formate, a reaction that is catalyzed by formate dehydrogenases (FDHs). FDHs catalyze, in general, the oxidation of formate to CO₂and H⁺. However, selected enzymes were identified to act as CO₂reductases, which are able to reduce CO₂to formate under physiological conditions. This reaction is of interest for the generation of formate as a convenient storage form of H₂for future applications. Cofactor-containing FDHs are found in anaerobic bacteria and archaea, in addition to facultative anaerobic or aerobic bacteria. These enzymes are highly diverse and employ different cofactors such as the molybdenum cofactor (Moco), FeS clusters and flavins, or cytochromes. Some enzymes include tungsten (W) in place of molybdenum (Mo) at the active site. For catalytic activity, a selenocysteine (SeCys) or cysteine (Cys) ligand at the Mo atom in the active site is essential for the reaction. This review will focus on the characterization of Mo- and W-containing FDHs from bacteria, their active site structure, subunit compositions and its proposed catalytic mechanism. We will give an overview on the different mechanisms of substrate conversion available so far, in addition to providing an outlook on bio-applications of FDHs. This article is part of a Special Issue entitled: Cofactor-dependent proteins: evolution, chemical diversity and bio-applications.
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Affiliation(s)
- Tobias Hartmann
- Institute of Biochemistry and Biology, Department of Molecular Enzymology, University of Potsdam, D-14476 Potsdam, Germany
| | - Nadine Schwanhold
- Institute of Biochemistry and Biology, Department of Molecular Enzymology, University of Potsdam, D-14476 Potsdam, Germany
| | - Silke Leimkühler
- Institute of Biochemistry and Biology, Department of Molecular Enzymology, University of Potsdam, D-14476 Potsdam, Germany.
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Maus I, Wibberg D, Stantscheff R, Stolze Y, Blom J, Eikmeyer FG, Fracowiak J, König H, Pühler A, Schlüter A. Insights into the annotated genome sequence of Methanoculleus bourgensis MS2(T), related to dominant methanogens in biogas-producing plants. J Biotechnol 2014; 201:43-53. [PMID: 25455016 DOI: 10.1016/j.jbiotec.2014.11.020] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Revised: 11/18/2014] [Accepted: 11/21/2014] [Indexed: 01/13/2023]
Abstract
The final step of the biogas production process, the methanogenesis, is frequently dominated by members of the genus Methanoculleus. In particular, the species Methanoculleus bourgensis was identified to play a role in different biogas reactor systems. The genome of the type strain M. bourgensis MS2(T), originally isolated from a sewage sludge digestor, was completely sequenced to analyze putative adaptive genome features conferring competitiveness within biogas reactor environments to the strain. Sequencing and assembly of the M. bourgensis MS2(T) genome yielded a chromosome with a size of 2,789,773 bp. Comparative analysis of M. bourgensis MS2(T) and Methanoculleus marisnigri JR1 revealed significant similarities. The absence of genes for a putative ammonium uptake system may indicate that M. bourgensis MS2(T) is adapted to environments rich in ammonium/ammonia. Specific genes featuring predicted functions in the context of osmolyte production were detected in the genome of M. bourgensis MS2(T). Mapping of metagenome sequences derived from a production-scale biogas plant revealed that M. bourgensis MS2(T) almost completely comprises the genetic information of dominant methanogens present in the biogas reactor analyzed. Hence, availability of the M. bourgensis MS2(T) genome sequence may be valuable regarding further research addressing the performance of Methanoculleus species in agricultural biogas plants.
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Affiliation(s)
- Irena Maus
- Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Daniel Wibberg
- Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Robbin Stantscheff
- Institute of Microbiology and Wine Research, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Yvonne Stolze
- Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Jochen Blom
- Department of Bioinformatics and Systems Biology, Justus-Liebig-University Gießen, Gießen, Germany
| | | | - Jochen Fracowiak
- Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Helmut König
- Institute of Microbiology and Wine Research, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Alfred Pühler
- Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Andreas Schlüter
- Center for Biotechnology, Bielefeld University, Bielefeld, Germany.
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Goyal N, Widiastuti H, Karimi IA, Zhou Z. A genome-scale metabolic model of Methanococcus maripaludis S2 for CO2 capture and conversion to methane. Mol Biosyst 2014; 10:1043-54. [PMID: 24553424 DOI: 10.1039/c3mb70421a] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Methane is a major energy source for heating and electricity. Its production by methanogenic bacteria is widely known in nature. M. maripaludis S2 is a fully sequenced hydrogenotrophic methanogen and an excellent laboratory strain with robust genetic tools. However, a quantitative systems biology model to complement these tools is absent in the literature. To understand and enhance its methanogenesis from CO2, this work presents the first constraint-based genome-scale metabolic model (iMM518). It comprises 570 reactions, 556 distinct metabolites, and 518 genes along with gene-protein-reaction (GPR) associations, and covers 30% of open reading frames (ORFs). The model was validated using biomass growth data and experimental phenotypic studies from the literature. Its comparison with the in silico models of Methanosarcina barkeri, Methanosarcina acetivorans, and Sulfolobus solfataricus P2 shows M. maripaludis S2 to be a better organism for producing methane. Using the model, genes essential for growth were identified, and the efficacies of alternative carbon, hydrogen and nitrogen sources were studied. The model can predict the effects of reengineering M. maripaludis S2 to guide or expedite experimental efforts.
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Affiliation(s)
- Nishu Goyal
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117576.
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Bräsen C, Esser D, Rauch B, Siebers B. Carbohydrate metabolism in Archaea: current insights into unusual enzymes and pathways and their regulation. Microbiol Mol Biol Rev 2014; 78:89-175. [PMID: 24600042 DOI: 10.1128/MMBR.00041-13] [Citation(s) in RCA: 200] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The metabolism of Archaea, the third domain of life, resembles in its complexity those of Bacteria and lower Eukarya. However, this metabolic complexity in Archaea is accompanied by the absence of many "classical" pathways, particularly in central carbohydrate metabolism. Instead, Archaea are characterized by the presence of unique, modified variants of classical pathways such as the Embden-Meyerhof-Parnas (EMP) pathway and the Entner-Doudoroff (ED) pathway. The pentose phosphate pathway is only partly present (if at all), and pentose degradation also significantly differs from that known for bacterial model organisms. These modifications are accompanied by the invention of "new," unusual enzymes which cause fundamental consequences for the underlying regulatory principles, and classical allosteric regulation sites well established in Bacteria and Eukarya are lost. The aim of this review is to present the current understanding of central carbohydrate metabolic pathways and their regulation in Archaea. In order to give an overview of their complexity, pathway modifications are discussed with respect to unusual archaeal biocatalysts, their structural and mechanistic characteristics, and their regulatory properties in comparison to their classic counterparts from Bacteria and Eukarya. Furthermore, an overview focusing on hexose metabolic, i.e., glycolytic as well as gluconeogenic, pathways identified in archaeal model organisms is given. Their energy gain is discussed, and new insights into different levels of regulation that have been observed so far, including the transcript and protein levels (e.g., gene regulation, known transcription regulators, and posttranslational modification via reversible protein phosphorylation), are presented.
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Kletzin A. General Characteristics and Important Model Organisms. In: Cavicchioli R, editor. Archaea. Washington: ASM Press; 2007. pp. 14-92. [DOI: 10.1128/9781555815516.ch2] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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