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Koch NG, Budisa N. Evolution of Pyrrolysyl-tRNA Synthetase: From Methanogenesis to Genetic Code Expansion. Chem Rev 2024. [PMID: 38953775 DOI: 10.1021/acs.chemrev.4c00031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/04/2024]
Abstract
Over 20 years ago, the pyrrolysine encoding translation system was discovered in specific archaea. Our Review provides an overview of how the once obscure pyrrolysyl-tRNA synthetase (PylRS) tRNA pair, originally responsible for accurately translating enzymes crucial in methanogenic metabolic pathways, laid the foundation for the burgeoning field of genetic code expansion. Our primary focus is the discussion of how to successfully engineer the PylRS to recognize new substrates and exhibit higher in vivo activity. We have compiled a comprehensive list of ncAAs incorporable with the PylRS system. Additionally, we also summarize recent successful applications of the PylRS system in creating innovative therapeutic solutions, such as new antibody-drug conjugates, advancements in vaccine modalities, and the potential production of new antimicrobials.
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Affiliation(s)
- Nikolaj G Koch
- Department of Chemistry, Institute of Physical Chemistry, University of Basel, 4058 Basel, Switzerland
- Department of Biosystems Science and Engineering, ETH Zurich, 4058 Basel, Switzerland
| | - Nediljko Budisa
- Biocatalysis Group, Institute of Chemistry, Technische Universität Berlin, 10623 Berlin, Germany
- Chemical Synthetic Biology Chair, Department of Chemistry, University of Manitoba, Winnipeg MB R3T 2N2, Canada
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2
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Hampton JT, Liu WR. Diversification of Phage-Displayed Peptide Libraries with Noncanonical Amino Acid Mutagenesis and Chemical Modification. Chem Rev 2024; 124:6051-6077. [PMID: 38686960 PMCID: PMC11082904 DOI: 10.1021/acs.chemrev.4c00004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 04/11/2024] [Accepted: 04/15/2024] [Indexed: 05/02/2024]
Abstract
Sitting on the interface between biologics and small molecules, peptides represent an emerging class of therapeutics. Numerous techniques have been developed in the past 30 years to take advantage of biological methods to generate and screen peptide libraries for the identification of therapeutic compounds, with phage display being one of the most accessible techniques. Although traditional phage display can generate billions of peptides simultaneously, it is limited to expression of canonical amino acids. Recently, several groups have successfully undergone efforts to apply genetic code expansion to introduce noncanonical amino acids (ncAAs) with novel reactivities and chemistries into phage-displayed peptide libraries. In addition to biological methods, several different chemical approaches have also been used to install noncanonical motifs into phage libraries. This review focuses on these recent advances that have taken advantage of both biological and chemical means for diversification of phage libraries with ncAAs.
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Affiliation(s)
- J. Trae Hampton
- Texas
A&M Drug Discovery Center and Department of Chemistry, College
of Arts and Sciences, Texas A&M University, College Station, Texas 77843, United States
| | - Wenshe Ray Liu
- Texas
A&M Drug Discovery Center and Department of Chemistry, College
of Arts and Sciences, Texas A&M University, College Station, Texas 77843, United States
- Institute
of Biosciences and Technology and Department of Translational Medical
Sciences, College of Medicine, Texas A&M
University, Houston, Texas 77030, United States
- Department
of Biochemistry and Biophysics, College of Agriculture and Life Sciences, Texas A&M University, College Station, Texas 77843, United States
- Department
of Cell Biology and Genetics, College of Medicine, Texas A&M University, College
Station, Texas 77843, United States
- Department
of Pharmaceutical Sciences, Irma Lerma Rangel College of Pharmacy, Texas A&M University, College Station, Texas 77843, United States
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3
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Xie F, Zhao S, Zhan X, Zhou Y, Li Y, Zhu W, Pope PB, Attwood GT, Jin W, Mao S. Unraveling the phylogenomic diversity of Methanomassiliicoccales and implications for mitigating ruminant methane emissions. Genome Biol 2024; 25:32. [PMID: 38263062 PMCID: PMC10804542 DOI: 10.1186/s13059-024-03167-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 01/07/2024] [Indexed: 01/25/2024] Open
Abstract
BACKGROUND Methanomassiliicoccales are a recently identified order of methanogens that are diverse across global environments particularly the gastrointestinal tracts of animals; however, their metabolic capacities are defined via a limited number of cultured strains. RESULTS Here, we profile and analyze 243 Methanomassiliicoccales genomes assembled from cultured representatives and uncultured metagenomes recovered from various biomes, including the gastrointestinal tracts of different animal species. Our analyses reveal the presence of numerous undefined genera and genetic variability in metabolic capabilities within Methanomassiliicoccales lineages, which is essential for adaptation to their ecological niches. In particular, gastrointestinal tract Methanomassiliicoccales demonstrate the presence of co-diversified members with their hosts over evolutionary timescales and likely originated in the natural environment. We highlight the presence of diverse clades of vitamin transporter BtuC proteins that distinguish Methanomassiliicoccales from other archaeal orders and likely provide a competitive advantage in efficiently handling B12. Furthermore, genome-centric metatranscriptomic analysis of ruminants with varying methane yields reveal elevated expression of select Methanomassiliicoccales genera in low methane animals and suggest that B12 exchanges could enable them to occupy ecological niches that possibly alter the direction of H2 utilization. CONCLUSIONS We provide a comprehensive and updated account of divergent Methanomassiliicoccales lineages, drawing from numerous uncultured genomes obtained from various habitats. We also highlight their unique metabolic capabilities involving B12, which could serve as promising targets for mitigating ruminant methane emissions by altering H2 flow.
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Affiliation(s)
- Fei Xie
- Ruminant Nutrition and Feed Engineering Technology Research Center, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
- Laboratory of Gastrointestinal Microbiology, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, National Center for International Research on Animal Gut Nutrition, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Shengwei Zhao
- Ruminant Nutrition and Feed Engineering Technology Research Center, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
- Laboratory of Gastrointestinal Microbiology, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, National Center for International Research on Animal Gut Nutrition, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Xiaoxiu Zhan
- Ruminant Nutrition and Feed Engineering Technology Research Center, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
- Laboratory of Gastrointestinal Microbiology, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, National Center for International Research on Animal Gut Nutrition, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Yang Zhou
- Ruminant Nutrition and Feed Engineering Technology Research Center, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
- Laboratory of Gastrointestinal Microbiology, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, National Center for International Research on Animal Gut Nutrition, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Yin Li
- Ruminant Nutrition and Feed Engineering Technology Research Center, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
- Laboratory of Gastrointestinal Microbiology, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, National Center for International Research on Animal Gut Nutrition, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Weiyun Zhu
- Ruminant Nutrition and Feed Engineering Technology Research Center, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
- Laboratory of Gastrointestinal Microbiology, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, National Center for International Research on Animal Gut Nutrition, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Phillip B Pope
- Department of Animal and Aquacultural Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, Ås, Norway
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Graeme T Attwood
- AgResearch Limited, Grasslands Research Centre, Palmerston North, New Zealand
| | - Wei Jin
- Ruminant Nutrition and Feed Engineering Technology Research Center, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China.
- Laboratory of Gastrointestinal Microbiology, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, National Center for International Research on Animal Gut Nutrition, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China.
| | - Shengyong Mao
- Ruminant Nutrition and Feed Engineering Technology Research Center, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China.
- Laboratory of Gastrointestinal Microbiology, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, National Center for International Research on Animal Gut Nutrition, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China.
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Ellenbogen JB, Borton MA, McGivern BB, Cronin DR, Hoyt DW, Freire-Zapata V, McCalley CK, Varner RK, Crill PM, Wehr RA, Chanton JP, Woodcroft BJ, Tfaily MM, Tyson GW, Rich VI, Wrighton KC. Methylotrophy in the Mire: direct and indirect routes for methane production in thawing permafrost. mSystems 2024; 9:e0069823. [PMID: 38063415 PMCID: PMC10805028 DOI: 10.1128/msystems.00698-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 10/24/2023] [Indexed: 01/24/2024] Open
Abstract
While wetlands are major sources of biogenic methane (CH4), our understanding of resident microbial metabolism is incomplete, which compromises the prediction of CH4 emissions under ongoing climate change. Here, we employed genome-resolved multi-omics to expand our understanding of methanogenesis in the thawing permafrost peatland of Stordalen Mire in Arctic Sweden. In quadrupling the genomic representation of the site's methanogens and examining their encoded metabolism, we revealed that nearly 20% of the metagenome-assembled genomes (MAGs) encoded the potential for methylotrophic methanogenesis. Further, 27% of the transcriptionally active methanogens expressed methylotrophic genes; for Methanosarcinales and Methanobacteriales MAGs, these data indicated the use of methylated oxygen compounds (e.g., methanol), while for Methanomassiliicoccales, they primarily implicated methyl sulfides and methylamines. In addition to methanogenic methylotrophy, >1,700 bacterial MAGs across 19 phyla encoded anaerobic methylotrophic potential, with expression across 12 phyla. Metabolomic analyses revealed the presence of diverse methylated compounds in the Mire, including some known methylotrophic substrates. Active methylotrophy was observed across all stages of a permafrost thaw gradient in Stordalen, with the most frozen non-methanogenic palsa found to host bacterial methylotrophy and the partially thawed bog and fully thawed fen seen to house both methanogenic and bacterial methylotrophic activities. Methanogenesis across increasing permafrost thaw is thus revised from the sole dominance of hydrogenotrophic production and the appearance of acetoclastic at full thaw to consider the co-occurrence of methylotrophy throughout. Collectively, these findings indicate that methanogenic and bacterial methylotrophy may be an important and previously underappreciated component of carbon cycling and emissions in these rapidly changing wetland habitats.IMPORTANCEWetlands are the biggest natural source of atmospheric methane (CH4) emissions, yet we have an incomplete understanding of the suite of microbial metabolism that results in CH4 formation. Specifically, methanogenesis from methylated compounds is excluded from all ecosystem models used to predict wetland contributions to the global CH4 budget. Though recent studies have shown methylotrophic methanogenesis to be active across wetlands, the broad climatic importance of the metabolism remains critically understudied. Further, some methylotrophic bacteria are known to produce methanogenic by-products like acetate, increasing the complexity of the microbial methylotrophic metabolic network. Prior studies of Stordalen Mire have suggested that methylotrophic methanogenesis is irrelevant in situ and have not emphasized the bacterial capacity for metabolism, both of which we countered in this study. The importance of our findings lies in the significant advancement toward unraveling the broader impact of methylotrophs in wetland methanogenesis and, consequently, their contribution to the terrestrial global carbon cycle.
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Affiliation(s)
- Jared B. Ellenbogen
- Department of Soil and Crop Science, Colorado State University, Fort Collins, Colorado, USA
| | - Mikayla A. Borton
- Department of Soil and Crop Science, Colorado State University, Fort Collins, Colorado, USA
| | - Bridget B. McGivern
- Department of Soil and Crop Science, Colorado State University, Fort Collins, Colorado, USA
| | - Dylan R. Cronin
- Department of Microbiology, The Ohio State University, Columbus, Ohio, USA
| | - David W. Hoyt
- Environmental Molecular Sciences Laboratory, Earth and Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington, USA
| | | | - Carmody K. McCalley
- Gosnell School of Life Sciences, Rochester Institute of Technology, Rochester, New York, USA
| | - Ruth K. Varner
- Department of Earth Sciences and Institute for the Study of Earth, Oceans and Space, University of New Hampshire, Durham, New Hampshire, USA
| | - Patrick M. Crill
- Department of Geological Sciences, Bolin Center for Climate Research, Stockholm University, Stockholm, Sweden
| | - Richard A. Wehr
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona, USA
| | - Jeffrey P. Chanton
- Earth Ocean and Atmospheric Sciences, Florida State University, Tallahassee, Florida, USA
| | - Ben J. Woodcroft
- Centre for Microbiome Research, School of Biomedical Sciences, Queensland University of Technology (QUT), Translational Research Institute, Woolloongabba, Queensland, Australia
| | - Malak M. Tfaily
- Department of Environmental Science, University of Arizona, Tucson, Arizona, USA
| | - Gene W. Tyson
- Centre for Microbiome Research, School of Biomedical Sciences, Queensland University of Technology (QUT), Translational Research Institute, Woolloongabba, Queensland, Australia
| | - Virginia I. Rich
- Department of Microbiology, The Ohio State University, Columbus, Ohio, USA
| | - Kelly C. Wrighton
- Department of Soil and Crop Science, Colorado State University, Fort Collins, Colorado, USA
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5
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Tsola SL, Zhu Y, Chen Y, Sanders IA, Economou CK, Brüchert V, Eyice Ö. Methanolobus use unspecific methyltransferases to produce methane from dimethylsulphide in Baltic Sea sediments. MICROBIOME 2024; 12:3. [PMID: 38172958 PMCID: PMC10762971 DOI: 10.1186/s40168-023-01720-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 11/14/2023] [Indexed: 01/05/2024]
Abstract
BACKGROUND In anoxic coastal and marine sediments, degradation of methylated compounds is the major route to the production of methane, a powerful greenhouse gas. Dimethylsulphide (DMS) is the most abundant biogenic organic sulphur compound in the environment and an abundant methylated compound leading to methane production in anoxic sediments. However, understanding of the microbial diversity driving DMS-dependent methanogenesis is limited, and the metabolic pathways underlying this process in the environment remain unexplored. To address this, we used anoxic incubations, amplicon sequencing, genome-centric metagenomics and metatranscriptomics of brackish sediments collected along the depth profile of the Baltic Sea with varying sulphate concentrations. RESULTS We identified Methanolobus as the dominant methylotrophic methanogens in all our DMS-amended sediment incubations (61-99%) regardless of their sulphate concentrations. We also showed that the mtt and mta genes (trimethylamine- and methanol-methyltransferases) from Methanolobus were highly expressed when the sediment samples were incubated with DMS. Furthermore, we did not find mtsA and mtsB (methylsulphide-methyltransferases) in metatranscriptomes, metagenomes or in the Methanolobus MAGs, whilst mtsD and mtsF were found 2-3 orders of magnitude lower in selected samples. CONCLUSIONS Our study demonstrated that the Methanolobus genus is likely the key player in anaerobic DMS degradation in brackish Baltic Sea sediments. This is also the first study analysing the metabolic pathways of anaerobic DMS degradation in the environment and showing that methylotrophic methane production from DMS may not require a substrate-specific methyltransferase as was previously accepted. This highlights the versatility of the key enzymes in methane production in anoxic sediments, which would have significant implications for the global greenhouse gas budget and the methane cycle. Video Abstract.
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Affiliation(s)
- S L Tsola
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, UK
| | - Y Zhu
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, UK
| | - Y Chen
- School of Life Sciences, University of Warwick, Coventry, UK
| | - I A Sanders
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, UK
| | - C K Economou
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, UK
| | - V Brüchert
- Department of Geological Sciences, Stockholm University, Stockholm, Sweden
- Bolin Centre for Climate Research, Stockholm University, Stockholm, Sweden
| | - Ö Eyice
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, UK.
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6
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Liu S, Hu R, Peng N, Zhou Z, Chen R, He Z, Wang C. Phylogenetic and ecophysiological novelty of subsurface mercury methylators in mangrove sediments. THE ISME JOURNAL 2023; 17:2313-2325. [PMID: 37880540 PMCID: PMC10689504 DOI: 10.1038/s41396-023-01544-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 10/12/2023] [Accepted: 10/13/2023] [Indexed: 10/27/2023]
Abstract
Mangrove sediment is a crucial component in the global mercury (Hg) cycling and acts as a hotspot for methylmercury (MeHg) production. Early evidence has documented the ubiquity of well-studied Hg methylators in mangrove superficial sediments; however, their diversity and metabolic adaptation in the more anoxic and highly reduced subsurface sediments are lacking. Through MeHg biogeochemical assay and metagenomic sequencing, we found that mangrove subsurface sediments (20-100 cm) showed a less hgcA gene abundance but higher diversity of Hg methylators than superficial sediments (0-20 cm). Regional-scale investigation of mangrove subsurface sediments spanning over 1500 km demonstrated a prevalence and family-level novelty of Hg-methylating microbial lineages (i.e., those affiliated to Anaerolineae, Phycisphaerae, and Desulfobacterales). We proposed the candidate phylum Zixibacteria lineage with sulfate-reducing capacity as a currently understudied Hg methylator across anoxic environments. Unlike other Hg methylators, the Zixibacteria lineage does not use the Wood-Ljungdahl pathway but has unique capabilities of performing methionine synthesis to donate methyl groups. The absence of cobalamin biosynthesis pathway suggests that this Hg-methylating lineage may depend on its syntrophic partners (i.e., Syntrophobacterales members) for energy in subsurface sediments. Our results expand the diversity of subsurface Hg methylators and uncover their unique ecophysiological adaptations in mangrove sediments.
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Affiliation(s)
- Songfeng Liu
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou, 510006, China
| | - Ruiwen Hu
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou, 510006, China
| | - Nenglong Peng
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou, 510006, China
| | - Zhengyuan Zhou
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou, 510006, China
| | - Ruihan Chen
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou, 510006, China
| | - Zhili He
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou, 510006, China
| | - Cheng Wang
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou, 510006, China.
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7
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Arya CK, Maurya S, Ramanathan G. Insight into the metabolic pathways of Paracoccus sp. strain DMF: a non-marine halotolerant methylotroph capable of degrading aliphatic amines/amides. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:125947-125964. [PMID: 38010547 DOI: 10.1007/s11356-023-30858-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 10/31/2023] [Indexed: 11/29/2023]
Abstract
Paracoccus sp. strain DMF (P. DMF from henceforth) is a gram-negative heterotroph known to tolerate and utilize high concentrations of N,N-dimethylformamide (DMF). The work presented here elaborates on the metabolic pathways involved in the degradation of C1 compounds, many of which are well-known pollutants and toxic to the environment. Investigations on microbial growth and detection of metabolic intermediates corroborate the outcome of the functional genome analysis. Several classes of C1 compounds, such as methanol, methylated amines, aliphatic amides, and naturally occurring quaternary amines like glycine betaine, were tested as growth substrates. The detailed growth and kinetic parameter analyses reveal that P. DMF can efficiently aerobically degrade trimethylamine (TMA) and grow on quaternary amines such as glycine betaine. The results show that the mechanism for halotolerant adaptation in the presence of glycine betaine is dissimilar from those observed for conventional trehalose-mediated halotolerance in heterotrophic bacteria. In addition, a close genomic survey revealed the presence of a Co(I)-based substrate-specific corrinoid methyltransferase operon, referred to as mtgBC. This demethylation system has been associated with glycine betaine catabolism in anaerobic methanogens and is unknown in denitrifying aerobic heterotrophs. This report on an anoxic-specific demethylation system in an aerobic heterotroph is unique. Our finding exposes the metabolic potential for the degradation of a variety of C1 compounds by P. DMF, making it a novel organism of choice for remediating a wide range of possible environmental contaminants.
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Affiliation(s)
- Chetan Kumar Arya
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, India
| | - Shiwangi Maurya
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, India
| | - Gurunath Ramanathan
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, India.
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8
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Borton MA, Shaffer M, Hoyt DW, Jiang R, Ellenbogen JB, Purvine S, Nicora CD, Eder EK, Wong AR, Smulian AG, Lipton MS, Krzycki JA, Wrighton KC. Targeted curation of the gut microbial gene content modulating human cardiovascular disease. mBio 2023; 14:e0151123. [PMID: 37695138 PMCID: PMC10653893 DOI: 10.1128/mbio.01511-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 07/17/2023] [Indexed: 09/12/2023] Open
Abstract
IMPORTANCE One of the most-cited examples of the gut microbiome modulating human disease is the microbial metabolism of quaternary amines from protein-rich foods. By-products of this microbial processing promote atherosclerotic heart disease, a leading cause of human mortality globally. Our research addresses current knowledge gaps in our understanding of this microbial metabolism by holistically inventorying the microorganisms and expressed genes catalyzing critical atherosclerosis-promoting and -ameliorating reactions in the human gut. This led to the creation of an open-access resource, the Methylated Amine Gene Inventory of Catabolism database, the first systematic inventory of gut methylated amine metabolism. More importantly, using this resource we deliver here, we show for the first time that these gut microbial genes can predict human disease, paving the way for microbiota-inspired diagnostics and interventions.
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Affiliation(s)
- Mikayla A. Borton
- Department of Soil and Crop Sciences, Colorado State University, Fort Collins, Colorado, USA
| | - Michael Shaffer
- Department of Soil and Crop Sciences, Colorado State University, Fort Collins, Colorado, USA
| | - David W. Hoyt
- Environmental and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington, USA
| | - Ruisheng Jiang
- Department of Microbiology, The Ohio State University, Columbus, Ohio, USA
| | | | - Samuel Purvine
- Environmental and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington, USA
| | - Carrie D. Nicora
- Environmental and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington, USA
| | - Elizabeth K. Eder
- Environmental and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington, USA
| | - Allison R. Wong
- Environmental and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington, USA
| | - A. George Smulian
- Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| | - Mary S. Lipton
- Environmental and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington, USA
| | - Joseph A. Krzycki
- Department of Microbiology, The Ohio State University, Columbus, Ohio, USA
| | - Kelly C. Wrighton
- Department of Soil and Crop Sciences, Colorado State University, Fort Collins, Colorado, USA
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9
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Downing BE, Gupta D, Nayak DD. The dual role of a multi-heme cytochrome in methanogenesis: MmcA is important for energy conservation and carbon metabolism in Methanosarcina acetivorans. Mol Microbiol 2023; 119:350-363. [PMID: 36660820 DOI: 10.1111/mmi.15029] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 01/05/2023] [Accepted: 01/16/2023] [Indexed: 01/21/2023]
Abstract
Methanogenic archaea belonging to the Order Methanosarcinales conserve energy using an electron transport chain (ETC). In the genetically tractable strain Methanosarcina acetivorans, ferredoxin donates electrons to the ETC via the Rnf (Rhodobacter nitrogen fixation) complex. The Rnf complex in M. acetivorans, unlike its counterpart in Bacteria, contains a multiheme c-type cytochrome (MHC) subunit called MmcA. Early studies hypothesized MmcA is a critical component of Rnf, however recent work posits that the primary role of MmcA is facilitating extracellular electron transport. To explore the physiological role of MmcA, we characterized M. acetivorans mutants lacking either the entire Rnf complex (∆mmcA-rnf) or just the MmcA subunit (∆mmcA). Our data show that MmcA is essential for growth during acetoclastic methanogenesis but neither Rnf nor MmcA is required for methanogenic growth on methylated compounds. On methylated compounds, the absence of MmcA alone leads to a more severe growth defect compared to a Rnf deletion likely due to different strategies for ferredoxin oxidation that arise in each strain. Transcriptomic data suggest that the ∆mmcA mutant might oxidize ferredoxin by upregulating the cytosolic Wood-Ljundahl pathway for acetyl-CoA synthesis, whereas the ∆mmcA-rnf mutant may repurpose the F420 dehydrogenase complex (Fpo) to oxidize ferredoxin coupled to proton translocation. Beyond energy conservation, the deletion of rnf or mmcA leads to global transcriptional changes of genes involved in methanogenesis, carbon assimilation and regulation. Overall, our study provides systems-level insights into the non-overlapping roles of the Rnf bioenergetic complex and the associated MHC, MmcA.
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Affiliation(s)
- Blake E Downing
- Department of Plant and Microbial Biology, University of California, Berkeley, California, USA
| | - Dinesh Gupta
- Department of Molecular and Cell Biology, University of California, Berkeley, California, USA
| | - Dipti D Nayak
- Department of Molecular and Cell Biology, University of California, Berkeley, California, USA
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10
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Update of the Pyrrolysyl-tRNA Synthetase/tRNA Pyl Pair and Derivatives for Genetic Code Expansion. J Bacteriol 2023; 205:e0038522. [PMID: 36695595 PMCID: PMC9945579 DOI: 10.1128/jb.00385-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The cotranslational incorporation of pyrrolysine (Pyl), the 22nd proteinogenic amino acid, into proteins in response to the UAG stop codon represents an outstanding example of natural genetic code expansion. Genetic encoding of Pyl is conducted by the pyrrolysyl-tRNA synthetase (PylRS) and its cognate tRNA, tRNAPyl. Owing to the high tolerance of PylRS toward diverse amino acid substrates and great orthogonality in various model organisms, the PylRS/tRNAPyl-derived pairs are ideal for genetic code expansion to insert noncanonical amino acids (ncAAs) into proteins of interest. Since the discovery of cellular components involved in the biosynthesis and genetic encoding of Pyl, synthetic biologists have been enthusiastic about engineering PylRS/tRNAPyl-derived pairs to rewrite the genetic code of living cells. Recently, considerable progress has been made in understanding the molecular phylogeny, biochemical properties, and structural features of the PylRS/tRNAPyl pair, guiding its further engineering and optimization. In this review, we cover the basic and updated knowledge of the PylRS/tRNAPyl pair's unique characteristics that make it an outstanding tool for reprogramming the genetic code. In addition, we summarize the recent efforts to create efficient and (mutually) orthogonal PylRS/tRNAPyl-derived pairs for incorporation of diverse ncAAs by genome mining, rational design, and advanced directed evolution methods.
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11
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Li J, Kang PT, Jiang R, Lee JY, Soares JA, Krzycki JA, Chan MK. Insights into pyrrolysine function from structures of a trimethylamine methyltransferase and its corrinoid protein complex. Commun Biol 2023; 6:54. [PMID: 36646841 PMCID: PMC9842639 DOI: 10.1038/s42003-022-04397-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 12/21/2022] [Indexed: 01/18/2023] Open
Abstract
The 22nd genetically encoded amino acid, pyrrolysine, plays a unique role in the key step in the growth of methanogens on mono-, di-, and tri-methylamines by activating the methyl group of these substrates for transfer to a corrinoid cofactor. Previous crystal structures of the Methanosarcina barkeri monomethylamine methyltransferase elucidated the structure of pyrrolysine and provide insight into its role in monomethylamine activation. Herein, we report the second structure of a pyrrolysine-containing protein, the M. barkeri trimethylamine methyltransferase MttB, and its structure bound to sulfite, a substrate analog of trimethylamine. We also report the structure of MttB in complex with its cognate corrinoid protein MttC, which specifically receives the methyl group from the pyrrolysine-activated trimethylamine substrate during methanogenesis. Together these structures provide key insights into the role of pyrrolysine in methyl group transfer from trimethylamine to the corrinoid cofactor in MttC.
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Affiliation(s)
- Jiaxin Li
- grid.10784.3a0000 0004 1937 0482School of Life Sciences, and Center of Novel Biomaterials, The Chinese University of Hong Kong, Shatin, Hong Kong, China
| | - Patrick T. Kang
- grid.261103.70000 0004 0459 7529Department of Integrative Medical Sciences, College of Medicine, Northeast Ohio Medical University, Rootstown, OH 44272 USA ,grid.261331.40000 0001 2285 7943Ohio State University Biochemistry Program, Columbus, OH 43210 USA
| | - Ruisheng Jiang
- grid.261331.40000 0001 2285 7943Department of Microbiology, The Ohio State University, Columbus, OH 43210 USA
| | - Jodie Y. Lee
- grid.261331.40000 0001 2285 7943Department of Microbiology, The Ohio State University, Columbus, OH 43210 USA ,grid.422834.b0000 0004 0387 4571TechLab, Inc., Blacksburg, VA 24060 USA
| | - Jitesh A. Soares
- grid.261331.40000 0001 2285 7943Department of Microbiology, The Ohio State University, Columbus, OH 43210 USA ,grid.286879.a0000 0001 1090 0879Division of Scientific Advancement, American Chemical Society, Washington, DC 20036 USA
| | - Joseph A. Krzycki
- grid.261331.40000 0001 2285 7943Ohio State University Biochemistry Program, Columbus, OH 43210 USA ,grid.261331.40000 0001 2285 7943Department of Microbiology, The Ohio State University, Columbus, OH 43210 USA
| | - Michael K. Chan
- grid.10784.3a0000 0004 1937 0482School of Life Sciences, and Center of Novel Biomaterials, The Chinese University of Hong Kong, Shatin, Hong Kong, China ,grid.261331.40000 0001 2285 7943Ohio State University Biochemistry Program, Columbus, OH 43210 USA
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12
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Holland SI, Vázquez-Campos X, Ertan H, Edwards RJ, Manefield MJ, Lee M. Metaproteomics reveals methyltransferases implicated in dichloromethane and glycine betaine fermentation by ' Candidatus Formimonas warabiya' strain DCMF. Front Microbiol 2022; 13:1035247. [PMID: 36569084 PMCID: PMC9768040 DOI: 10.3389/fmicb.2022.1035247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 11/15/2022] [Indexed: 12/12/2022] Open
Abstract
Dichloromethane (DCM; CH2Cl2) is a widespread pollutant with anthropogenic and natural sources. Anaerobic DCM-dechlorinating bacteria use the Wood-Ljungdahl pathway, yet dechlorination reaction mechanisms remain unclear and the enzyme(s) responsible for carbon-chlorine bond cleavage have not been definitively identified. Of the three bacterial taxa known to carry out anaerobic dechlorination of DCM, 'Candidatus Formimonas warabiya' strain DCMF is the only organism that can also ferment non-chlorinated substrates, including quaternary amines (i.e., choline and glycine betaine) and methanol. Strain DCMF is present within enrichment culture DFE, which was derived from an organochlorine-contaminated aquifer. We utilized the metabolic versatility of strain DCMF to carry out comparative metaproteomics of cultures grown with DCM or glycine betaine. This revealed differential abundance of numerous proteins, including a methyltransferase gene cluster (the mec cassette) that was significantly more abundant during DCM degradation, as well as highly conserved amongst anaerobic DCM-degrading bacteria. This lends strong support to its involvement in DCM dechlorination. A putative glycine betaine methyltransferase was also discovered, adding to the limited knowledge about the fate of this widespread osmolyte in anoxic subsurface environments. Furthermore, the metagenome of enrichment culture DFE was assembled, resulting in five high quality and two low quality draft metagenome-assembled genomes. Metaproteogenomic analysis did not reveal any genes or proteins for utilization of DCM or glycine betaine in the cohabiting bacteria, supporting the previously held idea that they persist via necromass utilization.
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Affiliation(s)
- Sophie I. Holland
- Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW, Australia
| | - Xabier Vázquez-Campos
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Haluk Ertan
- School of Chemical Engineering, University of New South Wales, Sydney, NSW, Australia,Department of Molecular Biology and Genetics, Istanbul University, Istanbul, Turkey
| | - Richard J. Edwards
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Michael J. Manefield
- Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW, Australia,School of Chemical Engineering, University of New South Wales, Sydney, NSW, Australia
| | - Matthew Lee
- Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW, Australia,*Correspondence: Matthew Lee,
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13
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Highlighting the Unique Roles of Radical S-Adenosylmethionine Enzymes in Methanogenic Archaea. J Bacteriol 2022; 204:e0019722. [PMID: 35880875 PMCID: PMC9380564 DOI: 10.1128/jb.00197-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Radical S-adenosylmethionine (SAM) enzymes catalyze an impressive variety of difficult biochemical reactions in various pathways across all domains of life. These metalloenzymes employ a reduced [4Fe-4S] cluster and SAM to generate a highly reactive 5'-deoxyadenosyl radical that is capable of initiating catalysis on otherwise unreactive substrates. Interestingly, the genomes of methanogenic archaea encode many unique radical SAM enzymes with underexplored or completely unknown functions. These organisms are responsible for the yearly production of nearly 1 billion tons of methane, a potent greenhouse gas as well as a valuable energy source. Thus, understanding the details of methanogenic metabolism and elucidating the functions of essential enzymes in these organisms can provide insights into strategies to decrease greenhouse gas emissions as well as inform advances in bioenergy production processes. This minireview provides an overview of the current state of the field regarding the functions of radical SAM enzymes in methanogens and discusses gaps in knowledge that should be addressed.
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14
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Chadwick GL, Skennerton CT, Laso-Pérez R, Leu AO, Speth DR, Yu H, Morgan-Lang C, Hatzenpichler R, Goudeau D, Malmstrom R, Brazelton WJ, Woyke T, Hallam SJ, Tyson GW, Wegener G, Boetius A, Orphan VJ. Comparative genomics reveals electron transfer and syntrophic mechanisms differentiating methanotrophic and methanogenic archaea. PLoS Biol 2022; 20:e3001508. [PMID: 34986141 PMCID: PMC9012536 DOI: 10.1371/journal.pbio.3001508] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 04/15/2022] [Accepted: 12/08/2021] [Indexed: 11/25/2022] Open
Abstract
The anaerobic oxidation of methane coupled to sulfate reduction is a microbially mediated process requiring a syntrophic partnership between anaerobic methanotrophic (ANME) archaea and sulfate-reducing bacteria (SRB). Based on genome taxonomy, ANME lineages are polyphyletic within the phylum Halobacterota, none of which have been isolated in pure culture. Here, we reconstruct 28 ANME genomes from environmental metagenomes and flow sorted syntrophic consortia. Together with a reanalysis of previously published datasets, these genomes enable a comparative analysis of all marine ANME clades. We review the genomic features that separate ANME from their methanogenic relatives and identify what differentiates ANME clades. Large multiheme cytochromes and bioenergetic complexes predicted to be involved in novel electron bifurcation reactions are well distributed and conserved in the ANME archaea, while significant variations in the anabolic C1 pathways exists between clades. Our analysis raises the possibility that methylotrophic methanogenesis may have evolved from a methanotrophic ancestor. A comparative genomics study of anaerobic methanotrophic (ANME) archaea reveals the genetic "parts list" associated with the repeated evolutionary transition between methanogenic and methanotrophic metabolism in the archaeal domain of life.
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Affiliation(s)
- Grayson L. Chadwick
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, United States of America
- * E-mail: (GLC); (VJO)
| | - Connor T. Skennerton
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, United States of America
| | - Rafael Laso-Pérez
- Max-Planck Institute for Marine Microbiology, Bremen, Germany
- MARUM, Center for Marine Environmental Science, and Department of Geosciences, University of Bremen, Bremen, Germany
| | - Andy O. Leu
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia
| | - Daan R. Speth
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, United States of America
| | - Hang Yu
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, United States of America
| | - Connor Morgan-Lang
- Graduate Program in Bioinformatics, University of British Columbia, Genome Sciences Centre, Vancouver, British Columbia, Canada
| | - Roland Hatzenpichler
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, United States of America
| | - Danielle Goudeau
- US Department of Energy Joint Genome Institute, Berkeley, California, United States of America
| | - Rex Malmstrom
- US Department of Energy Joint Genome Institute, Berkeley, California, United States of America
| | - William J. Brazelton
- School of Biological Sciences, University of Utah, Salt Lake City, Utah, United States of America
| | - Tanja Woyke
- US Department of Energy Joint Genome Institute, Berkeley, California, United States of America
| | - Steven J. Hallam
- Graduate Program in Bioinformatics, University of British Columbia, Genome Sciences Centre, Vancouver, British Columbia, Canada
- Department of Microbiology & Immunology, University of British Columbia, British Columbia, Canada
- Genome Science and Technology Program, University of British Columbia, Vancouver, British Columbia, Canada
- ECOSCOPE Training Program, University of British Columbia, Vancouver, British Columbia, Canada
- Life Sciences Institute, University of British Columbia, British Columbia, Canada
| | - Gene W. Tyson
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia
| | - Gunter Wegener
- Max-Planck Institute for Marine Microbiology, Bremen, Germany
- MARUM, Center for Marine Environmental Science, and Department of Geosciences, University of Bremen, Bremen, Germany
| | - Antje Boetius
- Max-Planck Institute for Marine Microbiology, Bremen, Germany
- MARUM, Center for Marine Environmental Science, and Department of Geosciences, University of Bremen, Bremen, Germany
- Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany
| | - Victoria J. Orphan
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, United States of America
- * E-mail: (GLC); (VJO)
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15
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Ragsdale SW. Not a 'they' but a 'we': the microbiome helps promote our well-being. J Biol Chem 2021; 298:101511. [PMID: 34929162 PMCID: PMC8800098 DOI: 10.1016/j.jbc.2021.101511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/13/2021] [Indexed: 11/18/2022] Open
Abstract
Anaerobic microbes in the human gut produce beneficial and harmful compounds, as well as neutral compounds like trimethylamine (TMA), which undergoes microbial metabolism or host-catalyzed transformation into proatherogenic trimethylamine-N-oxide (TMAO). Ellenbogen et al. identified a microbiome-associated demethylase that short-circuits the production of TMAO from the metabolite γ-butyrobetaine and instead produces methyltetrahydrofolate, a key intermediate in the microbial production of beneficial small chain fatty acids. This paper highlights an example of how the microbiome is integrally involved in producing metabolites that support our health and in preventing the formation of compounds that promote disease.
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Affiliation(s)
- Stephen W Ragsdale
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan, USA.
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16
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The MttB superfamily member MtyB from the human gut symbiont Eubacterium limosum is a cobalamin-dependent γ-butyrobetaine methyltransferase. J Biol Chem 2021; 297:101327. [PMID: 34688665 PMCID: PMC8604678 DOI: 10.1016/j.jbc.2021.101327] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 10/05/2021] [Accepted: 10/06/2021] [Indexed: 12/12/2022] Open
Abstract
The production of trimethylamine (TMA) from quaternary amines such as l-carnitine or γ-butyrobetaine (4-(trimethylammonio)butanoate) by gut microbial enzymes has been linked to heart disease. This has led to interest in enzymes of the gut microbiome that might ameliorate net TMA production, such as members of the MttB superfamily of proteins, which can demethylate TMA (e.g., MttB) or l-carnitine (e.g., MtcB). Here, we show that the human gut acetogen Eubacterium limosum demethylates γ-butyrobetaine and produces MtyB, a previously uncharacterized MttB superfamily member catalyzing the demethylation of γ-butyrobetaine. Proteomic analyses of E. limosum grown on either γ-butyrobetaine or dl-lactate were employed to identify candidate proteins underlying catabolic demethylation of the growth substrate. Three proteins were significantly elevated in abundance in γ-butyrobetaine-grown cells: MtyB, MtqC (a corrinoid-binding protein), and MtqA (a corrinoid:tetrahydrofolate methyltransferase). Together, these proteins act as a γ-butyrobetaine:tetrahydrofolate methyltransferase system, forming a key intermediate of acetogenesis. Recombinant MtyB acts as a γ-butyrobetaine:MtqC methyltransferase but cannot methylate free cobalamin cofactor. MtyB is very similar to MtcB, the carnitine methyltransferase, but neither was detectable in cells grown on carnitine nor was detectable in cells grown with γ-butyrobetaine. Both quaternary amines are substrates for either enzyme, but kinetic analysis revealed that, in comparison to MtcB, MtyB has a lower apparent Km for γ-butyrobetaine and higher apparent Vmax, providing a rationale for MtyB abundance in γ-butyrobetaine-grown cells. As TMA is readily produced from γ-butyrobetaine, organisms with MtyB-like proteins may provide a means to lower levels of TMA and proatherogenic TMA-N-oxide via precursor competition.
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17
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Kivenson V, Paul BG, Valentine DL. An Ecological Basis for Dual Genetic Code Expansion in Marine Deltaproteobacteria. Front Microbiol 2021; 12:680620. [PMID: 34335502 PMCID: PMC8318568 DOI: 10.3389/fmicb.2021.680620] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 05/20/2021] [Indexed: 01/04/2023] Open
Abstract
Marine benthic environments may be shaped by anthropogenic and other localized events, leading to changes in microbial community composition evident decades after a disturbance. Marine sediments in particular harbor exceptional taxonomic diversity and can shed light on distinctive evolutionary strategies. Genetic code expansion is a strategy that increases the structural and functional diversity of proteins in cells, by repurposing stop codons to encode non-canonical amino acids: pyrrolysine (Pyl) and selenocysteine (Sec). Here, we report both a study of the microbiome at a deep sea industrial waste dumpsite and an unanticipated discovery of codon reassignment in its most abundant member, with potential ramifications for interpreting microbial interactions with ocean-dumped wastes. The genomes of abundant Deltaproteobacteria from the sediments of a deep-ocean chemical waste dump site have undergone genetic code expansion. Pyl and Sec in these organisms appear to augment trimethylamine (TMA) and one-carbon metabolism, representing an increased metabolic versatility. The inferred metabolism of these sulfate-reducing bacteria places them in competition with methylotrophic methanogens for TMA, a contention further supported by earlier isotope tracer studies and reanalysis of metatranscriptomic studies. A survey of genomic data further reveals a broad geographic distribution of a niche group of similarly specialized Deltaproteobacteria, including at sulfidic sites in the Atlantic Ocean, Gulf of Mexico, Guaymas Basin, and North Sea, as well as in terrestrial and estuarine environments. These findings reveal an important biogeochemical role for specialized Deltaproteobacteria at the interface of the carbon, nitrogen, selenium, and sulfur cycles, with their niche adaptation and ecological success potentially augmented by genetic code expansion.
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Affiliation(s)
- Veronika Kivenson
- Interdepartmental Graduate Program in Marine Science, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Blair G. Paul
- Department of Earth Science and Marine Science Institute, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - David L. Valentine
- Department of Earth Science and Marine Science Institute, University of California, Santa Barbara, Santa Barbara, CA, United States
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18
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Kröber E, Cunningham MR, Peixoto J, Spurgin L, Wischer D, Kruger R, Kumaresan D. Comparative genomics analyses indicate differential methylated amine utilization trait within members of the genus Gemmobacter. ENVIRONMENTAL MICROBIOLOGY REPORTS 2021; 13:195-208. [PMID: 33484104 DOI: 10.1111/1758-2229.12927] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 01/11/2021] [Accepted: 01/11/2021] [Indexed: 05/22/2023]
Abstract
Methylated amines are ubiquitous in the environment and play a role in regulating the earth's climate via a set of complex biological and chemical reactions. Microbial degradation of these compounds is thought to be a major sink. Recently we isolated a facultative methylotroph, Gemmobacter sp. LW-1, an isolate from the unique environment Movile Cave, Romania, which is capable of methylated amine utilization as a carbon source. Here, using a comparative genomics approach, we investigate how widespread methylated amine utilization is within members of the bacterial genus Gemmobacter. Seven genomes of different Gemmobacter species isolated from diverse environments, such as activated sludge, fresh water, sulphuric cave waters (Movile Cave) and the marine environment were available from the public repositories and used for the analysis. Our results indicate that methylamine utilization is a distinctive feature of selected members of the genus Gemmobacter, namely G. aquatilis, G. lutimaris, G. sp. HYN0069, G. caeni and G. sp. LW-1 have the genetic potential while others (G. megaterium and G. nectariphilus) have not.
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Affiliation(s)
- Eileen Kröber
- Department of Symbiosis, Max-Planck Institute for Marine Microbiology, Bremen, Germany
| | - Mark R Cunningham
- School of Biological Sciences, Institute for Global Food Security, Queen's University Belfast, Belfast, UK
| | - Julianna Peixoto
- Department of Cellular Biology, University of Brasília, Brasília, Brazil
| | - Lewis Spurgin
- School of Environmental Sciences, University of East Anglia, Norwich, UK
| | - Daniela Wischer
- School of Environmental Sciences, University of East Anglia, Norwich, UK
| | - Ricardo Kruger
- Department of Cellular Biology, University of Brasília, Brasília, Brazil
| | - Deepak Kumaresan
- School of Biological Sciences, Institute for Global Food Security, Queen's University Belfast, Belfast, UK
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Molecular Evidence for an Active Microbial Methane Cycle in Subsurface Serpentinite-Hosted Groundwaters in the Samail Ophiolite, Oman. Appl Environ Microbiol 2021; 87:AEM.02068-20. [PMID: 33127818 DOI: 10.1128/aem.02068-20] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 10/20/2020] [Indexed: 01/04/2023] Open
Abstract
Serpentinization can generate highly reduced fluids replete with hydrogen (H2) and methane (CH4), potent reductants capable of driving microbial methanogenesis and methanotrophy, respectively. However, CH4 in serpentinized waters is thought to be primarily abiogenic, raising key questions about the relative importance of methanogens and methanotrophs in the production and consumption of CH4 in these systems. Herein, we apply molecular approaches to examine the functional capability and activity of microbial CH4 cycling in serpentinization-impacted subsurface waters intersecting multiple rock and water types within the Samail Ophiolite of Oman. Abundant 16S rRNA genes and transcripts affiliated with the methanogenic genus Methanobacterium were recovered from the most alkaline (pH, >10), H2- and CH4-rich subsurface waters. Additionally, 16S rRNA genes and transcripts associated with the aerobic methanotrophic genus Methylococcus were detected in wells that spanned varied fluid geochemistry. Metagenomic sequencing yielded genes encoding homologs of proteins involved in the hydrogenotrophic pathway of microbial CH4 production and in microbial CH4 oxidation. Transcripts of several key genes encoding methanogenesis/methanotrophy enzymes were identified, predominantly in communities from the most hyperalkaline waters. These results indicate active methanogenic and methanotrophic populations in waters with hyperalkaline pH in the Samail Ophiolite, thereby supporting a role for biological CH4 cycling in aquifers that undergo low-temperature serpentinization.IMPORTANCE Serpentinization of ultramafic rock can generate conditions favorable for microbial methane (CH4) cycling, including the abiotic production of hydrogen (H2) and possibly CH4 Systems of low-temperature serpentinization are geobiological targets due to their potential to harbor microbial life and ubiquity throughout Earth's history. Biomass in fracture waters collected from the Samail Ophiolite of Oman, a system undergoing modern serpentinization, yielded DNA and RNA signatures indicative of active microbial methanogenesis and methanotrophy. Intriguingly, transcripts for proteins involved in methanogenesis were most abundant in the most highly reacted waters that have hyperalkaline pH and elevated concentrations of H2 and CH4 These findings suggest active biological methane cycling in serpentinite-hosted aquifers, even under extreme conditions of high pH and carbon limitation. These observations underscore the potential for microbial activity to influence the isotopic composition of CH4 in these systems, which is information that could help in identifying biosignatures of microbial activity on other planets.
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Abstract
Cardiovascular disease (CVD) has been linked to animal-based diets, which are a major source of trimethylamine (TMA), a precursor of the proatherogenic compound trimethylamine-N-oxide (TMAO). Human gut bacteria in the genus Bilophila have genomic signatures for genetic code expansion that could enable them to metabolize both TMA and its precursors without production of TMAO. We uncovered evidence that the Bilophila demethylation pathway is actively transcribed in gut microbiomes and that animal-based diets cause Bilophila to rapidly increase in abundance. CVD occurrence and Bilophila abundance in humans were significantly negatively correlated. These data lead us to propose that Bilophila, which is commonly regarded as a pathobiont, may play a role in mitigating cardiovascular disease. Human gut microbiomes have been shown to affect the development of a myriad of disease states, but mechanistic connections between diet, health, and microbiota have been challenging to establish. The hypothesis that Bilophila reduces cardiovascular disease by circumventing TMAO production offers a clearly defined mechanism with a potential human health impact, but investigations of Bilophila cell biology and ecology will be needed to fully evaluate these ideas.IMPORTANCE Links between trimethylamine-N-oxide (TMAO) and cardiovascular disease (CVD) have focused attention on mechanisms by which animal-based diets have negative health consequences. In a meta-analysis of data from foundational gut microbiome studies, we found evidence that specialized bacteria have and express a metabolic pathway that circumvents TMAO production and is often misannotated because it relies on genetic code expansion. This naturally occurring mechanism for TMAO attenuation is negatively correlated with CVD. Ultimately, these findings point to new avenues of research that could increase microbiome-informed understanding of human health and hint at potential biomedical applications in which specialized bacteria are used to curtail CVD development.
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21
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Abstract
Within the broad field of synthetic biology, genetic code expansion (GCE) techniques enable creation of proteins with an expanded set of amino acids. This may be invaluable for applications in therapeutics, bioremediation, and biocatalysis. Central to GCE are aminoacyl-tRNA synthetases (aaRSs) as they link a non-canonical amino acid (ncAA) to their cognate tRNA, allowing ncAA incorporation into proteins on the ribosome. The ncAA-acylating aaRSs and their tRNAs should not cross-react with 20 natural aaRSs and tRNAs in the host, i.e., they need to function as an orthogonal translating system. All current orthogonal aaRS•tRNA pairs have been engineered from naturally occurring molecules to change the aaRS's amino acid specificity or assign the tRNA to a liberated codon of choice. Here we discuss the importance of orthogonality in GCE, laboratory techniques employed to create designer aaRSs and tRNAs, and provide an overview of orthogonal aaRS•tRNA pairs for GCE purposes.
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Affiliation(s)
- Natalie Krahn
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, United States
| | - Jeffery M Tharp
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, United States
| | - Ana Crnković
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, United States
| | - Dieter Söll
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, United States.
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22
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Huening KA, Jiang R, Krzycki JA. Kinetic and substrate complex characterization of RamA, a corrinoid protein reductive activase from Methanosarcina barkeri. FEMS Microbiol Lett 2020; 367:5896951. [PMID: 32840570 DOI: 10.1093/femsle/fnaa128] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 07/27/2020] [Indexed: 12/30/2022] Open
Abstract
In microbial corrinoid-dependent methyltransferase systems, adventitious Co(I)-corrinoid oxidation halts catalysis and necessitates repair by ATP-dependent reductive activases. RamA, an activase with a C-terminal ferredoxin domain with two [4Fe-4S] clusters from methanogenic archaea, has been far less studied than the bacterial activases bearing an N-terminal ferredoxin domain with one [2Fe-2S] cluster. These differences suggest RamA might prove to have other distinctive characteristics. Here, we examine RamA kinetics and the stoichiometry of the corrinoid protein:RamA complex. Like bacterial activases, K+ stimulates RamA. Potassium stimulation had been questioned due to differences in the primary structure of bacterial and methanogen activases. Unlike one bacterial activase, ATP is not inhibitory allowing the first determination of apparent kinetic parameters for any corrinoid activase. Unlike bacterial activases, a single RamA monomer complexes a single corrinoid protein monomer. Alanine replacement of a RamA serine residue corresponding to the serine of one bacterial activase which ligates the corrinoid cobalt during complex formation led to only moderate changes in the kinetics of RamA. These results reveal new differences in the two types of corrinoid activases, and provide direct evidence for the proposal that corrinoid activases act as catalytic monomers, unlike other enzymes that couple ATP hydrolysis to difficult reductions.
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Affiliation(s)
- Katherine A Huening
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA
| | - Ruisheng Jiang
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA
| | - Joseph A Krzycki
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA.,The Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
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Kountz DJ, Behrman EJ, Zhang L, Krzycki JA. MtcB, a member of the MttB superfamily from the human gut acetogen Eubacterium limosum, is a cobalamin-dependent carnitine demethylase. J Biol Chem 2020; 295:11971-11981. [PMID: 32571881 PMCID: PMC7443480 DOI: 10.1074/jbc.ra120.012934] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 06/18/2020] [Indexed: 12/22/2022] Open
Abstract
The trimethylamine methyltransferase MttB is the first described member of a superfamily comprising thousands of microbial proteins. Most members of the MttB superfamily are encoded by genes that lack the codon for pyrrolysine characteristic of trimethylamine methyltransferases, raising questions about the activities of these proteins. The superfamily member MtcB is found in the human intestinal isolate Eubacterium limosum ATCC 8486, an acetogen that can grow by demethylation of l-carnitine. Here, we demonstrate that MtcB catalyzes l-carnitine demethylation. When growing on l-carnitine, E. limosum excreted the unusual biological product norcarnitine as well as acetate, butyrate, and caproate. Cellular extracts of E. limosum grown on l-carnitine, but not lactate, methylated cob-(I)alamin or tetrahydrofolate using l-carnitine as methyl donor. MtcB, along with the corrinoid protein MtqC and the methylcorrinoid:tetrahydrofolate methyltransferase MtqA, were much more abundant in E. limosum cells grown on l-carnitine than on lactate. Recombinant MtcB methylates either cob(I)alamin or Co(I)-MtqC in the presence of l-carnitine and, to a much lesser extent, γ-butyrobetaine. Other quaternary amines were not substrates. Recombinant MtcB, MtqC, and MtqA methylated tetrahydrofolate via l-carnitine, forming a key intermediate in the acetogenic Wood-Ljungdahl pathway. To our knowledge, MtcB methylation of cobalamin or Co(I)-MtqC represents the first described mechanism of biological l-carnitine demethylation. The conversion of l-carnitine and its derivative γ-butyrobetaine to trimethylamine by the gut microbiome has been linked to cardiovascular disease. The activities of MtcB and related proteins in E. limosum might demethylate proatherogenic quaternary amines and contribute to the perceived health benefits of this human gut symbiont.
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Affiliation(s)
- Duncan J Kountz
- Department of Microbiology, Ohio State University, Columbus, Ohio, USA
| | - Edward J Behrman
- Department of Chemistry and Biochemistry, Ohio State University, Columbus, Ohio, USA
| | - Liwen Zhang
- Campus Chemical Instrument Center Mass Spectrometry and Proteomics Facility, Ohio State University, Columbus, Ohio, USA
| | - Joseph A Krzycki
- Department of Microbiology, Ohio State University, Columbus, Ohio, USA; Ohio State Biochemistry Program, Ohio State University, Columbus, Ohio, USA.
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24
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Sokolovskaya OM, Shelton AN, Taga ME. Sharing vitamins: Cobamides unveil microbial interactions. Science 2020; 369:369/6499/eaba0165. [PMID: 32631870 DOI: 10.1126/science.aba0165] [Citation(s) in RCA: 88] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Microbial communities are essential to fundamental processes on Earth. Underlying the compositions and functions of these communities are nutritional interdependencies among individual species. One class of nutrients, cobamides (the family of enzyme cofactors that includes vitamin B12), is widely used for a variety of microbial metabolic functions, but these structurally diverse cofactors are synthesized by only a subset of bacteria and archaea. Advances at different scales of study-from individual isolates, to synthetic consortia, to complex communities-have led to an improved understanding of cobamide sharing. Here, we discuss how cobamides affect microbes at each of these three scales and how integrating different approaches leads to a more complete understanding of microbial interactions.
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Affiliation(s)
- Olga M Sokolovskaya
- Department of Plant & Microbial Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Amanda N Shelton
- Department of Plant & Microbial Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Michiko E Taga
- Department of Plant & Microbial Biology, University of California, Berkeley, Berkeley, CA, USA.
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25
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Picking JW, Behrman EJ, Zhang L, Krzycki JA. MtpB, a member of the MttB superfamily from the human intestinal acetogen Eubacterium limosum, catalyzes proline betaine demethylation. J Biol Chem 2019; 294:13697-13707. [PMID: 31341018 DOI: 10.1074/jbc.ra119.009886] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 07/22/2019] [Indexed: 12/11/2022] Open
Abstract
The trimethylamine methyltransferase MttB is the founding member of a widely distributed superfamily of microbial proteins. Genes encoding most members of the MttB superfamily lack the codon for pyrrolysine that distinguishes previously characterized trimethylamine methyltransferases, leaving the function(s) of most of the enzymes in this superfamily unknown. Here, investigating the MttB family member MtpB from the human intestinal isolate Eubacterium limosum ATCC 8486, an acetogen that excretes N-methyl proline during growth on proline betaine, we demonstrate that MtpB catalyzes anoxic demethylation of proline betaine. MtpB along with MtqC (a corrinoid protein) and MtqA (a methylcorrinoid:tetrahydrofolate methyltransferase) was much more abundant in E. limosum cells grown on proline betaine than on lactate. We observed that recombinant MtpB methylates Co(I)-MtqC in the presence of proline betaine and that other quaternary amines are much less preferred substrates. MtpB, MtqC, and MtqA catalyze tetrahydrofolate methylation with proline betaine, thereby forming a key intermediate in the Wood-Ljungdahl acetogenesis pathway. To our knowledge, MtpB methylation of Co(I)-MtqC for the subsequent methylation of tetrahydrofolate represents the first described anoxic mechanism of proline betaine demethylation. The activities of MtpB and associated proteins in acetogens or other anaerobes provide a possible mechanism for the production of N-methyl proline by the gut microbiome. MtpB's activity characterized here strengthens the hypothesis that much of the MttB superfamily comprises quaternary amine-dependent methyltransferases.
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Affiliation(s)
- Jonathan W Picking
- Ohio State Biochemistry Program, Ohio State University, Columbus, Ohio 43210
| | - Edward J Behrman
- Department of Chemistry and Biochemistry, Ohio State University, Columbus, Ohio 43210
| | - Liwen Zhang
- Campus Chemical Instrument Center Mass Spectrometry and Proteomics Facility, Ohio State University, Columbus, Ohio 43210
| | - Joseph A Krzycki
- Ohio State Biochemistry Program, Ohio State University, Columbus, Ohio 43210 .,Department of Microbiology, Ohio State University, Columbus, Ohio 43210
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Abstract
Covering: up to the end of 2017 The human body is composed of an equal number of human and microbial cells. While the microbial community inhabiting the human gastrointestinal tract plays an essential role in host health, these organisms have also been connected to various diseases. Yet, the gut microbial functions that modulate host biology are not well established. In this review, we describe metabolic functions of the human gut microbiota that involve metalloenzymes. These activities enable gut microbial colonization, mediate interactions with the host, and impact human health and disease. We highlight cases in which enzyme characterization has advanced our understanding of the gut microbiota and examples that illustrate the diverse ways in which metalloenzymes facilitate both essential and unique functions of this community. Finally, we analyze Human Microbiome Project sequencing datasets to assess the distribution of a prominent family of metalloenzymes in human-associated microbial communities, guiding future enzyme characterization efforts.
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Pyrrolysine in archaea: a 22nd amino acid encoded through a genetic code expansion. Emerg Top Life Sci 2018; 2:607-618. [PMID: 33525836 DOI: 10.1042/etls20180094] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 09/24/2018] [Accepted: 09/25/2018] [Indexed: 11/17/2022]
Abstract
The 22nd amino acid discovered to be directly encoded, pyrrolysine, is specified by UAG. Until recently, pyrrolysine was only known to be present in archaea from a methanogenic lineage (Methanosarcinales), where it is important in enzymes catalysing anoxic methylamines metabolism, and a few anaerobic bacteria. Relatively new discoveries have revealed wider presence in archaea, deepened functional understanding, shown remarkable carbon source-dependent expression of expanded decoding and extended exploitation of the pyrrolysine machinery for synthetic code expansion. At the same time, other studies have shown the presence of pyrrolysine-containing archaea in the human gut and this has prompted health considerations. The article reviews our knowledge of this fascinating exception to the 'standard' genetic code.
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28
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Kröninger L, Gottschling J, Deppenmeier U. Growth Characteristics of Methanomassiliicoccus luminyensis and Expression of Methyltransferase Encoding Genes. ARCHAEA (VANCOUVER, B.C.) 2017; 2017:2756573. [PMID: 29230105 PMCID: PMC5688252 DOI: 10.1155/2017/2756573] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 09/24/2017] [Indexed: 11/17/2022]
Abstract
DNA sequence analysis of the human gut revealed the presence a seventh order of methanogens referred to as Methanomassiliicoccales. Methanomassiliicoccus luminyensis is the only member of this order that grows in pure culture. Here, we show that the organism has a doubling time of 1.8 d with methanol + H2 and a growth yield of 2.4 g dry weight/mol CH4. M. luminyensis also uses methylamines + H2 (monomethylamine, dimethylamine, and trimethylamine) with doubling times of 2.1-2.3 d. Similar cell yields were obtained with equimolar concentrations of methanol and methylamines with respect to their methyl group contents. The transcript levels of genes encoding proteins involved in substrate utilization indicated increased amounts of mRNA from the mtaBC2 gene cluster in methanol-grown cells. When methylamines were used as substrates, mRNA of the mtb/mtt operon and of the mtmBC1 cluster were found in high abundance. The transcript level of mtaC2 was almost identical in methanol- and methylamine-grown cells, indicating that genes for methanol utilization were constitutively expressed in high amounts. The same observation was made with resting cells where methanol always yielded the highest CH4 production rate independently from the growth substrate. Hence, M. luminyensis is adapted to habitats that provide methanol + H2 as substrates.
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Affiliation(s)
- Lena Kröninger
- Institut für Mikrobiologie und Biotechnologie, Universität Bonn, Bonn, Germany
| | | | - Uwe Deppenmeier
- Institut für Mikrobiologie und Biotechnologie, Universität Bonn, Bonn, Germany
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Manzoor S, Bongcam-Rudloff E, Schnürer A, Müller B. Genome-Guided Analysis and Whole Transcriptome Profiling of the Mesophilic Syntrophic Acetate Oxidising Bacterium Syntrophaceticus schinkii. PLoS One 2016; 11:e0166520. [PMID: 27851830 PMCID: PMC5113046 DOI: 10.1371/journal.pone.0166520] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 10/31/2016] [Indexed: 01/29/2023] Open
Abstract
Syntrophaceticus schinkii is a mesophilic, anaerobic bacterium capable of oxidising acetate to CO2 and H2 in intimate association with a methanogenic partner, a syntrophic relationship which operates close to the energetic limits of microbial life. Syntrophaceticus schinkii has been identified as a key organism in engineered methane-producing processes relying on syntrophic acetate oxidation as the main methane-producing pathway. However, due to strict cultivation requirements and difficulties in reconstituting the thermodynamically unfavourable acetate oxidation, the physiology of this functional group is poorly understood. Genome-guided and whole transcriptome analyses performed in the present study provide new insights into habitat adaptation, syntrophic acetate oxidation and energy conservation. The working draft genome of Syntrophaceticus schinkii indicates limited metabolic capacities, with lack of organic nutrient uptake systems, chemotactic machineries, carbon catabolite repression and incomplete biosynthesis pathways. Ech hydrogenase, [FeFe] hydrogenases, [NiFe] hydrogenases, F1F0-ATP synthase and membrane-bound and cytoplasmic formate dehydrogenases were found clearly expressed, whereas Rnf and a predicted oxidoreductase/heterodisulphide reductase complex, both found encoded in the genome, were not expressed under syntrophic growth condition. A transporter sharing similarities to the high-affinity acetate transporters of aceticlastic methanogens was also found expressed, suggesting that Syntrophaceticus schinkii can potentially compete with methanogens for acetate. Acetate oxidation seems to proceed via the Wood-Ljungdahl pathway as all genes involved in this pathway were highly expressed. This study shows that Syntrophaceticus schinkii is a highly specialised, habitat-adapted organism relying on syntrophic acetate oxidation rather than metabolic versatility. By expanding its complement of respiratory complexes, it might overcome limiting bioenergetic barriers, and drive efficient energy conservation from reactions operating close to the thermodynamic equilibrium, which might enable S. schinkii to occupy the same niche as the aceticlastic methanogens. The knowledge gained here will help specify process conditions supporting efficient and robust biogas production and will help identify mechanisms important for the syntrophic lifestyle.
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Affiliation(s)
- Shahid Manzoor
- Department of Information Technology, University of the Punjab, Lahore, Pakistan
| | - Erik Bongcam-Rudloff
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Science, SLU-Global Bioinformatics Centre, Uppsala, SE 750 07, Sweden
| | - Anna Schnürer
- Department of Microbiology, Swedish University of Agricultural Sciences, BioCenter, Uppsala, SE 750 07, Sweden
| | - Bettina Müller
- Department of Microbiology, Swedish University of Agricultural Sciences, BioCenter, Uppsala, SE 750 07, Sweden
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30
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Wu WL, Lai SJ, Yang JT, Chern J, Liang SY, Chou CC, Kuo CH, Lai MC, Wu SH. Phosphoproteomic analysis of Methanohalophilus portucalensis FDF1(T) identified the role of protein phosphorylation in methanogenesis and osmoregulation. Sci Rep 2016; 6:29013. [PMID: 27357474 PMCID: PMC4928046 DOI: 10.1038/srep29013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 06/10/2016] [Indexed: 02/02/2023] Open
Abstract
Methanogens have gained much attention for their metabolic product, methane, which could be an energy substitute but also contributes to the greenhouse effect. One factor that controls methane emission, reversible protein phosphorylation, is a crucial signaling switch, and phosphoproteomics has become a powerful tool for large-scale surveying. Here, we conducted the first phosphorylation-mediated regulation study in halophilic Methanohalophilus portucalensis FDF1(T), a model strain for studying stress response mechanisms in osmoadaptation. A shotgun approach and MS-based analysis identified 149 unique phosphoproteins. Among them, 26% participated in methanogenesis and osmolytes biosynthesis pathways. Of note, we uncovered that protein phosphorylation might be a crucial factor to modulate the pyrrolysine (Pyl) incorporation and Pyl-mediated methylotrophic methanogenesis. Furthermore, heterologous expression of glycine sarcosine N-methyltransferase (GSMT) mutant derivatives in the osmosensitive Escherichia coli MKH13 revealed that the nonphosphorylated T68A mutant resulted in increased salt tolerance. In contrast, mimic phosphorylated mutant T68D proved defective in both enzymatic activity and salinity tolerance for growth. Our study provides new insights into phosphorylation modification as a crucial role of both methanogenesis and osmoadaptation in methanoarchaea, promoting biogas production or reducing future methane emission in response to global warming and climate change.
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Affiliation(s)
- Wan-Ling Wu
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
| | - Shu-Jung Lai
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
- Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan
| | - Jhih-Tian Yang
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
- Ph.D program in Microbial Genomics, National Chung Hsing University and Academia Sinica, Taichung 40227, Taiwan
| | - Jeffy Chern
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
- Chemical Biology and Molecular Biophysics Program, Taiwan International Graduate Program, Academia Sinica, Taipei 11529, Taiwan
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Suh-Yuen Liang
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
- Core Facilities for Protein Structural Analysis, Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
| | - Chi-Chi Chou
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
- Core Facilities for Protein Structural Analysis, Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
| | - Chih-Horng Kuo
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
- Agricultural Biotechnology Center, National Chung Hsing University, Taichung 40227, Taiwan
| | - Mei-Chin Lai
- Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan
- Agricultural Biotechnology Center, National Chung Hsing University, Taichung 40227, Taiwan
| | - Shih-Hsiung Wu
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
- Chemical Biology and Molecular Biophysics Program, Taiwan International Graduate Program, Academia Sinica, Taipei 11529, Taiwan
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
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31
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Crnković A, Suzuki T, Söll D, Reynolds NM. Pyrrolysyl-tRNA synthetase, an aminoacyl-tRNA synthetase for genetic code expansion. CROAT CHEM ACTA 2016; 89:163-174. [PMID: 28239189 PMCID: PMC5321558 DOI: 10.5562/cca2825] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Genetic code expansion (GCE) has become a central topic of synthetic biology. GCE relies on engineered aminoacyl-tRNA synthetases (aaRSs) and a cognate tRNA species to allow codon reassignment by co-translational insertion of non-canonical amino acids (ncAAs) into proteins. Introduction of such amino acids increases the chemical diversity of recombinant proteins endowing them with novel properties. Such proteins serve in sophisticated biochemical and biophysical studies both in vitro and in vivo, they may become unique biomaterials or therapeutic agents, and they afford metabolic dependence of genetically modified organisms for biocontainment purposes. In the Methanosarcinaceae the incorporation of the 22nd genetically encoded amino acid, pyrrolysine (Pyl), is facilitated by pyrrolysyl-tRNA synthetase (PylRS) and the cognate UAG-recognizing tRNAPyl. This unique aaRS•tRNA pair functions as an orthogonal translation system (OTS) in most model organisms. The facile directed evolution of the large PylRS active site to accommodate many ncAAs, and the enzyme's anticodon-blind specific recognition of the cognate tRNAPyl make this system highly amenable for GCE purposes. The remarkable polyspecificity of PylRS has been exploited to incorporate >100 different ncAAs into proteins. Here we review the Pyl-OT system and selected GCE applications to examine the properties of an effective OTS.
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Affiliation(s)
- Ana Crnković
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT 06520-8114, USA
| | - Tateki Suzuki
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT 06520-8114, USA
| | - Dieter Söll
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT 06520-8114, USA
- Department of Chemistry, Yale University, New Haven, CT 06520-8114, USA
| | - Noah M. Reynolds
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT 06520-8114, USA
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33
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Genomic and phenotypic differentiation among Methanosarcina mazei populations from Columbia River sediment. ISME JOURNAL 2015; 9:2191-205. [PMID: 25756680 DOI: 10.1038/ismej.2015.31] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 01/08/2015] [Accepted: 01/28/2015] [Indexed: 11/09/2022]
Abstract
Methanogenic archaea are genotypically and phenotypically diverse organisms that are integral to carbon cycling in anaerobic environments. Owing to their genetic tractability and ability to be readily cultivated, Methanosarcina spp. have become a powerful model system for understanding methanogen biology at the cellular systems level. However, relatively little is known of how genotypic and phenotypic variation is partitioned in Methanosarcina populations inhabiting natural environments and the possible ecological and evolutionary implications of such variation. Here, we have identified how genomic and phenotypic diversity is partitioned within and between Methanosarcina mazei populations obtained from two different sediment environments in the Columbia River Estuary (Oregon, USA). Population genomic analysis of 56 M. mazei isolates averaging <1% nucleotide divergence revealed two distinct clades, which we refer to as 'mazei-T' and 'mazei-WC'. Genomic analyses showed that these clades differed in gene content and fixation of allelic variants, which point to potential differences in primary metabolism and also interactions with foreign genetic elements. This hypothesis of niche partitioning was supported by laboratory growth experiments that revealed significant differences in trimethylamine utilization. These findings improve our understanding of the ecologically relevant scales of genomic variation in natural systems and demonstrate interactions between genetic and ecological diversity in these easily cultivable and genetically tractable model methanogens.
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Lang K, Schuldes J, Klingl A, Poehlein A, Daniel R, Brune A. New mode of energy metabolism in the seventh order of methanogens as revealed by comparative genome analysis of “Candidatus methanoplasma termitum”. Appl Environ Microbiol 2015; 81:1338-52. [PMID: 25501486 PMCID: PMC4309702 DOI: 10.1128/aem.03389-14] [Citation(s) in RCA: 149] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 12/08/2014] [Indexed: 11/20/2022] Open
Abstract
The recently discovered seventh order of methanogens, the Methanomassiliicoccales (previously referred to as “Methanoplasmatales”), so far consists exclusively of obligately hydrogen-dependent methylotrophs. We sequenced the complete genome of “Candidatus Methanoplasma termitum” from a highly enriched culture obtained from the intestinal tract of termites and compared it with the previously published genomes of three other strains from the human gut, including the first isolate of the order. Like all other strains, “Ca. Methanoplasma termitum” lacks the entire pathway for CO2 reduction to methyl coenzyme Mand produces methane by hydrogen-dependent reduction of methanol or methylamines, which is consistent with additional physiological data. However, the shared absence of cytochromes and an energy-converting hydrogenase for the reoxidation of the ferredoxin produced by the soluble heterodisulfide reductase indicates that Methanomassiliicoccales employ a new mode of energy metabolism, which differs from that proposed for the obligately methylotrophic Methanosphaera stadtmanae. Instead, all strains possess a novel complex that is related to the F420:methanophenazine oxidoreductase (Fpo) of Methanosarcinales butlacks an F420-oxidizing module, resembling the apparently ferredoxin-dependent Fpo-like homolog in Methanosaeta thermophila. Since all Methanomassiliicoccales also lack the subunit E of the membrane-bound heterodisulfide reductase (HdrDE), wepropose that the Fpo-like complex interacts directly with subunit D, forming an energy-converting ferredoxin: heterodisulfideoxidoreductase. The dual function of heterodisulfide in Methanomassiliicoccales, which serves both in electron bifurcation and as terminal acceptor in a membrane-associated redox process, may be a unique characteristic of the novel order.
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Affiliation(s)
- Kristina Lang
- Department of Biogeochemistry, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Jörg Schuldes
- Göttingen Genomics Laboratory, Institute for Microbiology and Genetics, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Andreas Klingl
- LOEWE Center for Synthetic Microbiology, Philipps-Universität Marburg, Marburg, Germany
| | - Anja Poehlein
- Göttingen Genomics Laboratory, Institute for Microbiology and Genetics, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Rolf Daniel
- Göttingen Genomics Laboratory, Institute for Microbiology and Genetics, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Andreas Brune
- Department of Biogeochemistry, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
- LOEWE Center for Synthetic Microbiology, Philipps-Universität Marburg, Marburg, Germany
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35
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Liu X, Luo Y, Mohamed OA, Liu D, Wei G. Global transcriptome analysis of Mesorhizobium alhagi CCNWXJ12-2 under salt stress. BMC Microbiol 2014; 14:1. [PMID: 25539655 PMCID: PMC4302635 DOI: 10.1186/s12866-014-0319-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 12/11/2014] [Indexed: 11/24/2022] Open
Abstract
Background Mesorhizobium alhagi CCNWXJ12-2 is a α-proteobacterium which could be able to fix nitrogen in the nodules formed with Alhagi sparsifolia in northwest of China. Desiccation and high salinity are the two major environmental problems faced by M. alhagi CCNWXJ12-2. In order to identify genes involved in salt-stress adaption, a global transcriptional analysis of M. alhagi CCNWXJ12-2 growing under salt-free and high salt conditions was carried out. The next generation sequencing technology, RNA-Seq, was used to obtain the transcription profiles. Results We have compared the transcriptome of M. alhagi growing in TY medium under high salt conditions (0.4 M NaCl) with salt free conditions as a control. A total of 1,849 differentially expressed genes (fold change ≧ 2) were identified and 933 genes were downregulated while 916 genes were upregulated under high salt condition. Except for the upregulation of some genes proven to be involved in salt resistance, we found that the expression levels of protein secretion systems were changed under high salt condition and the expression levels of some heat shock proteins were reduced by salt stress. Notably, a gene encoding YadA domain-containing protein (yadA), a gene encoding trimethylamine methyltransferase (mttB) and a gene encoding formate--tetrahydrofolate ligase (fhs) were highly upregulated. Growth analysis of the three gene knockout mutants under salt stress demonstrated that yadA was involved in salt resistance while the other two were not. Conclusions To our knowledge, this is the first report about transcriptome analysis of a rhizobia using RNA-Seq to elucidate the salt resistance mechanism. Our results showed the complex mechanism of bacterial adaption to salt stress and it was a systematic work for bacteria to cope with the high salinity environmental problems. Therefore, these results could be helpful for further investigation of the bacterial salt resistance mechanism. Electronic supplementary material The online version of this article (doi:10.1186/s12866-014-0319-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | | | | | - Gehong Wei
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,, College of Life Sciences, Northwest A&F University, Yangling 712100, Shaanxi, China.
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Purwantini E, Torto-Alalibo T, Lomax J, Setubal JC, Tyler BM, Mukhopadhyay B. Genetic resources for methane production from biomass described with the Gene Ontology. Front Microbiol 2014; 5:634. [PMID: 25520705 PMCID: PMC4253957 DOI: 10.3389/fmicb.2014.00634] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Accepted: 11/05/2014] [Indexed: 11/21/2022] Open
Abstract
Methane (CH4) is a valuable fuel, constituting 70–95% of natural gas, and a potent greenhouse gas. Release of CH4 into the atmosphere contributes to climate change. Biological CH4 production or methanogenesis is mostly performed by methanogens, a group of strictly anaerobic archaea. The direct substrates for methanogenesis are H2 plus CO2, acetate, formate, methylamines, methanol, methyl sulfides, and ethanol or a secondary alcohol plus CO2. In numerous anaerobic niches in nature, methanogenesis facilitates mineralization of complex biopolymers such as carbohydrates, lipids and proteins generated by primary producers. Thus, methanogens are critical players in the global carbon cycle. The same process is used in anaerobic treatment of municipal, industrial and agricultural wastes, reducing the biological pollutants in the wastes and generating methane. It also holds potential for commercial production of natural gas from renewable resources. This process operates in digestive systems of many animals, including cattle, and humans. In contrast, in deep-sea hydrothermal vents methanogenesis is a primary production process, allowing chemosynthesis of biomaterials from H2 plus CO2. In this report we present Gene Ontology (GO) terms that can be used to describe processes, functions and cellular components involved in methanogenic biodegradation and biosynthesis of specialized coenzymes that methanogens use. Some of these GO terms were previously available and the rest were generated in our Microbial Energy Gene Ontology (MENGO) project. A recently discovered non-canonical CH4 production process is also described. We have performed manual GO annotation of selected methanogenesis genes, based on experimental evidence, providing “gold standards” for machine annotation and automated discovery of methanogenesis genes or systems in diverse genomes. Most of the GO-related information presented in this report is available at the MENGO website (http://www.mengo.biochem.vt.edu/).
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Affiliation(s)
- Endang Purwantini
- Department of Biochemistry, Virginia Polytechnic Institute and State University Blacksburg, VA, USA
| | - Trudy Torto-Alalibo
- Department of Biochemistry, Virginia Polytechnic Institute and State University Blacksburg, VA, USA
| | - Jane Lomax
- European Bioinformatics Institute (EMBL-EBI), European Molecular Biology Laboratory Hinxton, UK
| | - João C Setubal
- Department of Biochemistry, Universidade de São Paulo São Paulo, Brazil ; Virginia Bioinformatics Institute, Virginia Polytechnic Institute and State University Blacksburg, VA, USA
| | - Brett M Tyler
- Virginia Bioinformatics Institute, Virginia Polytechnic Institute and State University Blacksburg, VA, USA ; Center for Genome Research and Biocomputing, Oregon State University Corvallis, OR, USA
| | - Biswarup Mukhopadhyay
- Department of Biochemistry, Virginia Polytechnic Institute and State University Blacksburg, VA, USA ; Virginia Bioinformatics Institute, Virginia Polytechnic Institute and State University Blacksburg, VA, USA ; Department of Biological Sciences, Virginia Polytechnic Institute and State University Blacksburg, VA, USA
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37
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Wan W, Tharp JM, Liu WR. Pyrrolysyl-tRNA synthetase: an ordinary enzyme but an outstanding genetic code expansion tool. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2014; 1844:1059-70. [PMID: 24631543 DOI: 10.1016/j.bbapap.2014.03.002] [Citation(s) in RCA: 284] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Revised: 03/01/2014] [Accepted: 03/05/2014] [Indexed: 11/16/2022]
Abstract
The genetic incorporation of the 22nd proteinogenic amino acid, pyrrolysine (Pyl) at amber codon is achieved by the action of pyrrolysyl-tRNA synthetase (PylRS) together with its cognate tRNA(Pyl). Unlike most aminoacyl-tRNA synthetases, PylRS displays high substrate side chain promiscuity, low selectivity toward its substrate α-amine, and low selectivity toward the anticodon of tRNA(Pyl). These unique but ordinary features of PylRS as an aminoacyl-tRNA synthetase allow the Pyl incorporation machinery to be easily engineered for the genetic incorporation of more than 100 non-canonical amino acids (NCAAs) or α-hydroxy acids into proteins at amber codon and the reassignment of other codons such as ochre UAA, opal UGA, and four-base AGGA codons to code NCAAs.
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Affiliation(s)
- Wei Wan
- Department of Chemistry, Texas A&M University, College Station, TX 77845, USA
| | - Jeffery M Tharp
- Department of Chemistry, Texas A&M University, College Station, TX 77845, USA
| | - Wenshe R Liu
- Department of Chemistry, Texas A&M University, College Station, TX 77845, USA.
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Unique characteristics of the pyrrolysine system in the 7th order of methanogens: implications for the evolution of a genetic code expansion cassette. ARCHAEA-AN INTERNATIONAL MICROBIOLOGICAL JOURNAL 2014; 2014:374146. [PMID: 24669202 PMCID: PMC3941956 DOI: 10.1155/2014/374146] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 10/19/2013] [Indexed: 02/06/2023]
Abstract
Pyrrolysine (Pyl), the 22nd proteogenic amino acid, was restricted until recently to few organisms. Its translational use necessitates the presence of enzymes for synthesizing it from lysine, a dedicated amber stop codon suppressor tRNA, and a specific amino-acyl tRNA synthetase. The three genomes of the recently proposed Thermoplasmata-related 7th order of methanogens contain the complete genetic set for Pyl synthesis and its translational use. Here, we have analyzed the genomic features of the Pyl-coding system in these three genomes with those previously known from Bacteria and Archaea and analyzed the phylogeny of each component. This shows unique peculiarities, notably an amber tRNAPyl with an imperfect anticodon stem and a shortened tRNAPyl synthetase. Phylogenetic analysis indicates that a Pyl-coding system was present in the ancestor of the seventh order of methanogens and appears more closely related to Bacteria than to Methanosarcinaceae, suggesting the involvement of lateral gene transfer in the spreading of pyrrolysine between the two prokaryotic domains. We propose that the Pyl-coding system likely emerged once in Archaea, in a hydrogenotrophic and methanol-H2-dependent methylotrophic methanogen. The close relationship between methanogenesis and the Pyl system provides a possible example of expansion of a still evolving genetic code, shaped by metabolic requirements.
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Krzycki JA. The path of lysine to pyrrolysine. Curr Opin Chem Biol 2013; 17:619-25. [PMID: 23856058 DOI: 10.1016/j.cbpa.2013.06.023] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 06/12/2013] [Accepted: 06/17/2013] [Indexed: 01/05/2023]
Abstract
Pyrrolysine is the 22nd genetically encoded amino acid. For many years, its biosynthesis has been primarily a matter for conjecture. Recently, a pathway for the synthesis of pyrrolysine from two molecules of lysine was outlined in which a radical SAM enzyme acts as a lysine mutase to generate a methylated ornithine from lysine, which is then ligated to form an amide with the ɛ-amine of a second lysine. Oxidation of the isopeptide gives rise to pyrrolysine. Mechanisms have been proposed for both the mutase and the ligase, and structures now exist for each, setting the stage for a more detailed understanding of how pyrrolysine is synthesized and functions in bacteria and archaea.
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Affiliation(s)
- Joseph A Krzycki
- Department of Microbiology, 484 West 12th Avenue, Columbus, OH 43210, United States.
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40
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Kornobis K, Ruud K, Kozlowski PM. Cob(I)alamin: insight into the nature of electronically excited states elucidated via quantum chemical computations and analysis of absorption, CD and MCD data. J Phys Chem A 2013; 117:863-76. [PMID: 23281629 DOI: 10.1021/jp310446c] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The nature of electronically excited states of the super-reduced form of vitamin B(12) (i.e., cob(I)alamin or B(12s)), a ubiquitous B(12) intermediate, was investigated by performing quantum-chemical calculations within the time-dependent density functional theory (TD-DFT) framework and by establishing their correspondence to experimental data. Using response theory, the electronic absorption (Abs), circular dichroism (CD) and magnetic CD (MCD) spectra of cob(I)alamin were simulated and directly compared with experiment. Several issues have been taken into considerations while performing the TD-DFT calculations, such as strong dependence on the applied exchange-correlation (XC) functional or structural simplification imposed on the cob(I)alamin. In addition, the low-lying transitions were also validated by performing CASSCF/MC-XQDPT2 calculations. By comparing computational results with existing experimental data a new level of understanding of electronic excitations has been established at the molecular level. The present study extends and confirms conclusions reached for other cobalamins. In particular, the better performance of the BP86 functional, rather than hybrid-type, was observed in terms of the excitations associated with both Co d and corrin π localized transitions. In addition, the lowest energy band was associated with multiple metal-to-ligand charge transfer excitations as opposed to the commonly assumed view of a single π → π* transition followed by vibrational progression. Finally, the use of the full cob(I)alamin structure, instead of simplified molecular models, shed new light on the spectral analyses of cobalamin systems and revealed new challenges of this approach related to long-range charge transfer excitations involving side chains.
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Affiliation(s)
- Karina Kornobis
- Department of Chemistry, University of Louisville, 2320 South Brook Street, Louisville, Kentucky 40292, United States
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Co+–H interaction inspired alternate coordination geometries of biologically important cob(I)alamin: possible structural and mechanistic consequences for methyltransferases. J Biol Inorg Chem 2012; 17:1107-21. [DOI: 10.1007/s00775-012-0924-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Accepted: 07/03/2012] [Indexed: 10/28/2022]
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Jiang R, Krzycki JA. PylSn and the homologous N-terminal domain of pyrrolysyl-tRNA synthetase bind the tRNA that is essential for the genetic encoding of pyrrolysine. J Biol Chem 2012; 287:32738-46. [PMID: 22851181 DOI: 10.1074/jbc.m112.396754] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Pyrrolysine is represented by an amber codon in genes encoding proteins such as the methylamine methyltransferases present in some Archaea and Bacteria. Pyrrolysyl-tRNA synthetase (PylRS) attaches pyrrolysine to the amber-suppressing tRNA(Pyl). Archaeal PylRS, encoded by pylS, has a catalytic C-terminal domain but an N-terminal region of unknown function and structure. In Bacteria, homologs of the N- and C-terminal regions of archaeal PylRS are respectively encoded by pylSn and pylSc. We show here that wild type PylS from Methanosarcina barkeri and PylSn from Desulfitobacterium hafniense bind tRNA(Pyl) in EMSA with apparent K(d) values of 0.12 and 0.13 μM, respectively. Truncation of the N-terminal region of PylS eliminated detectable tRNA(Pyl) binding as measured by EMSA, but not catalytic activity. A chimeric protein with PylSn fused to the N terminus of truncated PylS regained EMSA-detectable tRNA(Pyl) binding. PylSn did not bind other D. hafniense tRNAs, nor did the competition by the Escherichia coli tRNA pool interfere with tRNA(Pyl) binding. Further indicating the specificity of PylSn interaction with tRNA(Pyl), substitutions of conserved residues in tRNA(Pyl) in the variable loop, D stem, and T stem and loop had significant impact in binding, whereas those having base changes in the acceptor stem or anticodon stem and loop still retained the ability to complex with PylSn. PylSn and the N terminus of PylS comprise the protein superfamily TIGR03129. The members of this family are not similar to any known RNA-binding protein, but our results suggest their common function involves specific binding of tRNA(Pyl).
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Affiliation(s)
- Ruisheng Jiang
- Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio 43210, USA
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The complete biosynthesis of the genetically encoded amino acid pyrrolysine from lysine. Nature 2011; 471:647-50. [PMID: 21455182 PMCID: PMC3070376 DOI: 10.1038/nature09918] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2010] [Accepted: 02/09/2011] [Indexed: 11/24/2022]
Abstract
Pyrrolysine, the 22nd amino acid to be found in the natural genetic code1–4, is necessary for all known pathways of methane formation from methylamines5,6. The residue is comprised of a methylated pyrroline carboxylate in amide linkage to the ε-amino group of L-lysine2,7,8. The three different methyltransferases that initiate methanogenesis from different methylamines9–11 have genes with an in-frame amber codon12,13 translated as pyrrolysine2,7,8. E. coli transformed with pylTSBCD from methanogenic Archaea can incorporate endogenously biosynthesized pyrrolysine into protein14. The decoding of UAG as pyrrolysine requires pylT1,6 which produces tRNAPyl (also called tRNACUA), and pylS1 encoding a pyrrolysyl-tRNA synthetase4,15,16. The pylBCD genes1 are each required for tRNA-independent pyrrolysine synthesis14. Pyrrolysine has been the last remaining genetically encoded amino acid with an unknown biosynthetic pathway. Here, we provide genetic and mass spectroscopic evidence for a pylBCD-dependent pathway in which pyrrolysine arises from two lysines. We show that a new UAG encoded residue, desmethylpyrrolysine, is made from lysine and exogenous D-ornithine in a pylC, then a pylD, dependent process, but is not further converted to pyrrolysine. These results indicate that the radical S-adenosyl-methionine (SAM) protein PylB mediates a lysine mutase reaction producing 3-methylornithine, which is then ligated to a second molecule of lysine by PylC before oxidation by PylD results in pyrrolysine. The discovery of lysine as sole precursor to pyrrolysine will further inform discussions of the evolution the genetic code and amino acid biosynthetic pathways, while intermediates of the pathway may provide new avenues by which the pyl system may be exploited for production of recombinant proteins with useful modified residues.
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Gaston MA, Jiang R, Krzycki JA. Functional context, biosynthesis, and genetic encoding of pyrrolysine. Curr Opin Microbiol 2011; 14:342-9. [PMID: 21550296 DOI: 10.1016/j.mib.2011.04.001] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2011] [Revised: 04/01/2011] [Accepted: 04/06/2011] [Indexed: 01/14/2023]
Abstract
In Methanosarcina spp., amber codons in methylamine methyltransferase genes are translated as the 22nd amino acid, pyrrolysine. The responsible pyl genes plus amber-codon containing methyltransferase genes have been identified in four archaeal and five bacterial genera, including one human pathogen. In Escherichia coli, the recombinant pylBCD gene products biosynthesize pyrrolysine from two molecules of lysine and the pylTS gene products direct pyrrolysine incorporation into protein. In the proposed biosynthetic pathway, PylB forms methylornithine from lysine, which is joined to another lysine by PylC, and oxidized to pyrrolysine by PylD. Structures of the catalytic domain of pyrrolysyl-tRNA synthetase (archaeal PylS or bacterial PylSc) revealed binding sites for tRNAPyl and pyrrolysine. PylS and tRNAPyl are now being exploited as an orthogonal pair in recombinant systems for introduction of useful modified amino acids into proteins.
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Affiliation(s)
- Marsha A Gaston
- Department of Microbiology, 484 West 12th Avenue, The Ohio State University, Columbus, OH 43210, United States
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45
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Okumoto S, Pilot G. Amino acid export in plants: a missing link in nitrogen cycling. MOLECULAR PLANT 2011; 4:453-63. [PMID: 21324969 PMCID: PMC3143828 DOI: 10.1093/mp/ssr003] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2010] [Accepted: 12/24/2010] [Indexed: 05/17/2023]
Abstract
The export of nutrients from source organs to parts of the body where they are required (e.g. sink organs) is a fundamental biological process. Export of amino acids, one of the most abundant nitrogen species in plant long-distance transport tissues (i.e. xylem and phloem), is an essential process for the proper distribution of nitrogen in the plant. Physiological studies have detected the presence of multiple amino acid export systems in plant cell membranes. Yet, surprisingly little is known about the molecular identity of amino acid exporters, partially due to the technical difficulties hampering the identification of exporter proteins. In this short review, we will summarize our current knowledge about amino acid export systems in plants. Several studies have described plant amino acid transporters capable of bi-directional, facilitative transport, reminiscent of activities identified by earlier physiological studies. Moreover, recent expansion in the number of available amino acid transporter sequences have revealed evolutionary relationships between amino acid exporters from other organisms with a number of uncharacterized plant proteins, some of which might also function as amino acid exporters. In addition, genes that may regulate export of amino acids have been discovered. Studies of these putative transporter and regulator proteins may help in understanding the elusive molecular mechanisms of amino acid export in plants.
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Affiliation(s)
- Sakiko Okumoto
- 549 Latham Hall, Virginia Tech, Blacksburg, VA 24061, USA.
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46
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Selenocysteine, pyrrolysine, and the unique energy metabolism of methanogenic archaea. ARCHAEA-AN INTERNATIONAL MICROBIOLOGICAL JOURNAL 2010; 2010. [PMID: 20847933 PMCID: PMC2933860 DOI: 10.1155/2010/453642] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Accepted: 07/13/2010] [Indexed: 01/21/2023]
Abstract
Methanogenic archaea are a group of strictly anaerobic microorganisms characterized by their strict dependence on the process of methanogenesis for energy conservation. Among the archaea, they are also the only known group synthesizing proteins containing selenocysteine or pyrrolysine. All but one of the known archaeal pyrrolysine-containing and all but two of the confirmed archaeal selenocysteine-containing protein are involved in methanogenesis. Synthesis of these proteins proceeds through suppression of translational stop codons but otherwise the two systems are fundamentally different. This paper highlights these differences and summarizes the recent developments in selenocysteine- and pyrrolysine-related research on archaea and aims to put this knowledge into the context of their unique energy metabolism.
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47
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Lukashenko NP. Expanding genetic code: Amino acids 21 and 22, selenocysteine and pyrrolysine. RUSS J GENET+ 2010. [DOI: 10.1134/s1022795410080016] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Shih CJ, Lai MC. Differentially expressed genes after hyper- and hypo-salt stress in the halophilic archaeonMethanohalophilus portucalensis. Can J Microbiol 2010; 56:295-307. [DOI: 10.1139/w10-008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Methanohalophilus portucalensis FDF1 can grow over a range of external NaCl concentrations, from 1.2 to 2.9 mol/L. Differential gene expression in response to long-term hyper-salt stress (3.1 mol/L of NaCl) and hypo-salt stress (0.9 mol/L of NaCl) were compared by differential display RT-PCR. Fourteen differentially expressed genes responding to long-term hyper- or hypo-salt stress were detected, cloned, and sequenced. Several of the differentially expressed genes were related to the unique energy-acquiring methanogenesis pathway in this organism, including the transmembrane protein MttP, cobalamin biosynthesis protein, methenyl-H4MPT cyclohydrolase and monomethylamine methyltransferase. One signal transduction histidine kinase was identified from the hyper-salt stress cultures. Moreover, 3 known stress-response gene homologues — the DNA mismatch repair protein, MutS, the universal stress protein, UspA, and a member of the protein-disaggregating multichaperone system, ClpB — were also detected. The transcriptional analysis of these long-term salt stress response and adaptation-related genes for cells immediately after salt stress indicated that the expression of the energy metabolism genes was arrested during hyper-salt shock, while the chaperone clpB gene was stimulated by both hypo- and hyper-salt shock.
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Affiliation(s)
- Chao-Jen Shih
- Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan, ROC
| | - Mei-Chin Lai
- Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan, ROC
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Williams TJ, Burg DW, Ertan H, Raftery MJ, Poljak A, Guilhaus M, Cavicchioli R. Global Proteomic Analysis of the Insoluble, Soluble, and Supernatant Fractions of the Psychrophilic Archaeon Methanococcoides burtonii Part II: The Effect of Different Methylated Growth Substrates. J Proteome Res 2009; 9:653-63. [DOI: 10.1021/pr9005102] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Timothy J. Williams
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, 2052, NSW, Australia, Department of Molecular Biology and Genetics, Science Faculty, Istanbul University, Vezneciler, Istanbul, Turkey, Bioanalytical Mass Spectrometry Facility, The University of New South Wales, Sydney, 2052, NSW, Australia, and School of Medical Sciences, The University of New South Wales, Sydney, 2052, Australia
| | - Dominic W. Burg
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, 2052, NSW, Australia, Department of Molecular Biology and Genetics, Science Faculty, Istanbul University, Vezneciler, Istanbul, Turkey, Bioanalytical Mass Spectrometry Facility, The University of New South Wales, Sydney, 2052, NSW, Australia, and School of Medical Sciences, The University of New South Wales, Sydney, 2052, Australia
| | - Haluk Ertan
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, 2052, NSW, Australia, Department of Molecular Biology and Genetics, Science Faculty, Istanbul University, Vezneciler, Istanbul, Turkey, Bioanalytical Mass Spectrometry Facility, The University of New South Wales, Sydney, 2052, NSW, Australia, and School of Medical Sciences, The University of New South Wales, Sydney, 2052, Australia
| | - Mark J. Raftery
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, 2052, NSW, Australia, Department of Molecular Biology and Genetics, Science Faculty, Istanbul University, Vezneciler, Istanbul, Turkey, Bioanalytical Mass Spectrometry Facility, The University of New South Wales, Sydney, 2052, NSW, Australia, and School of Medical Sciences, The University of New South Wales, Sydney, 2052, Australia
| | - Anne Poljak
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, 2052, NSW, Australia, Department of Molecular Biology and Genetics, Science Faculty, Istanbul University, Vezneciler, Istanbul, Turkey, Bioanalytical Mass Spectrometry Facility, The University of New South Wales, Sydney, 2052, NSW, Australia, and School of Medical Sciences, The University of New South Wales, Sydney, 2052, Australia
| | - Michael Guilhaus
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, 2052, NSW, Australia, Department of Molecular Biology and Genetics, Science Faculty, Istanbul University, Vezneciler, Istanbul, Turkey, Bioanalytical Mass Spectrometry Facility, The University of New South Wales, Sydney, 2052, NSW, Australia, and School of Medical Sciences, The University of New South Wales, Sydney, 2052, Australia
| | - Ricardo Cavicchioli
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, 2052, NSW, Australia, Department of Molecular Biology and Genetics, Science Faculty, Istanbul University, Vezneciler, Istanbul, Turkey, Bioanalytical Mass Spectrometry Facility, The University of New South Wales, Sydney, 2052, NSW, Australia, and School of Medical Sciences, The University of New South Wales, Sydney, 2052, Australia
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50
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Transcriptional profiling of methyltransferase genes during growth of Methanosarcina mazei on trimethylamine. J Bacteriol 2009; 191:5108-15. [PMID: 19525341 DOI: 10.1128/jb.00420-09] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The genomic expression patterns of Methanosarcina mazei growing with trimethylamine were measured in comparison to those of cells grown with methanol. We identified a total of 72 genes with either an increased level (49 genes) or a decreased level (23 genes) of mRNA during growth on trimethylamine with methanol-grown cells as the control. Major differences in transcript levels were observed for the mta, mtb, mtt, and mtm genes, which encode enzymes involved in methane formation from methanol and trimethylamine, respectively. Other differences in mRNA abundance were found for genes encoding enzymes involved in isopentenyl pyrophosphate synthesis and in the formation of aromatic amino acids, as well as a number of proteins with unknown functions. The results were verified by in-depth analysis of methyltransferase genes using specific primers for real-time quantitative reverse transcription-PCR (RT-PCR). The monitored transcript levels of genes encoding corrinoid proteins involved in methyl group transfer from methylated C(1) compounds (mtaC, mtbC, mttC, and mtmC) indicated increased amounts of mRNA from the mtaBC1, mtaBC2, and mtaBC3 operons in methanol-grown cells, whereas mRNA of the mtb1-mtt1 operon was found in high concentrations during trimethylamine consumption. The genes of the mtb1-mtt1 operon encode methyltransferases that are responsible for sequential demethylation of trimethylamine. The analysis of product formation of trimethylamine-grown cells at different optical densities revealed that large amounts of dimethylamine and monomethylamine were excreted into the medium. The intermediate compounds were consumed only in the very late exponential growth phase. RT-PCR analysis of key genes involved in methanogenesis led to the conclusion that M. mazei is able to adapt to changing trimethylamine concentrations and the consumption of intermediate compounds. Hence, we assume that the organism possesses a regulatory network for optimal substrate utilization.
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