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Scott J, Amich J. The role of methionine synthases in fungal metabolism and virulence. Essays Biochem 2023; 67:853-863. [PMID: 37449444 DOI: 10.1042/ebc20230007] [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: 05/25/2023] [Revised: 06/20/2023] [Accepted: 06/20/2023] [Indexed: 07/18/2023]
Abstract
Methionine synthases (MetH) catalyse the methylation of homocysteine (Hcy) with 5-methyl-tetrahydrofolate (5, methyl-THF) acting as methyl donor, to form methionine (Met) and tetrahydrofolate (THF). This function is performed by two unrelated classes of enzymes that differ significantly in both their structures and mechanisms of action. The genomes of plants and many fungi exclusively encode cobalamin-independent enzymes (EC.2.1.1.14), while some fungi also possess proteins from the cobalamin-dependent (EC.2.1.1.13) family utilised by humans. Methionine synthase's function connects the methionine and folate cycles, making it a crucial node in primary metabolism, with impacts on important cellular processes such as anabolism, growth and synthesis of proteins, polyamines, nucleotides and lipids. As a result, MetHs are vital for the viability or virulence of numerous prominent human and plant pathogenic fungi and have been proposed as promising broad-spectrum antifungal drug targets. This review provides a summary of the relevance of methionine synthases to fungal metabolism, their potential as antifungal drug targets and insights into the structures of both classes of MetH.
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Affiliation(s)
- Jennifer Scott
- Manchester Fungal Infection Group, Division of Evolution, Infection, and Genomics, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Jorge Amich
- Manchester Fungal Infection Group, Division of Evolution, Infection, and Genomics, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- Mycology Reference Laboratory (Laboratorio de Referencia e Investigación en Micología [LRIM]), National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), Majadahonda, Madrid, Spain
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2
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Liu X, Zeng X, Zhu Y, Wang W, Huang S, Qiao X, Wang Z, Di H, Qu J. Degradation of betaine aldehyde dehydrogenase transgenic maize BZ-136 straw and its effects on soil nutrients and fungal community. Front Microbiol 2023; 14:1180310. [PMID: 37346754 PMCID: PMC10279975 DOI: 10.3389/fmicb.2023.1180310] [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: 03/06/2023] [Accepted: 05/18/2023] [Indexed: 06/23/2023] Open
Abstract
The development of salt-alkali tolerant genetically modified crops represents an important approach to increase grain production in saline-alkali soils. However, there is a paucity of research on the impact of such genetically modified crops on soil microbial diversity. This study aims to investigate the straw degradation of betaine aldehyde dehydrogenase (BADH) transgenic maize BZ-136 and its effects on soil chemical properties, fungal community composition, community diversity and ecological function compared to non-transgenic maize Zheng58 straw. The degradation experiments of BZ-136 straw were carried out under a simulated burying condition with saline-alkali soil for 210 days. The results showed that the degradation rate of C and N of BZ-136 straw was significantly faster than that of Zheng58 in the early stage (p < 0.05). Compared to Zheng58, the straw degradation of BZ-136 increased the soil available nitrogen (AN), total phosphorus (TP), and available phosphorus (AP) in the early stage (p < 0.05). The AN content of soil with BZ-136 straw was 18.16 and 12.86% higher than that of soil with Zheng58 at day 60 and 120 (p < 0.05). The TP content of soil with BZ-136 was higher 20.9 and 20.59% than that with Zheng58 at day 30 and 90 (p < 0.05). The AP content of soil with BZ-136 was 53.44% higher than that with Zheng58 at day 60 (p < 0.05). The straw degradation of BZ-136 increased the OTU number of soil fungal community by 127 (p < 0.05) at day 60, and increased Chao1 and Shannon index at day 60 and 180 (p < 0.05). The degradation rate of C and N in BZ-136 straw was higher than that in Zheng58 at early stage, which led to the phased increase of soil AN and TP contents, and the obvious changes of relative abundances (RA) of some genera and guilds. These findings are important as they provide insight into the potential benefits of BADH transgenic crops in upgrading the soil fertility and the fungal community diversity.
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Affiliation(s)
- Xuesheng Liu
- College of Resources and Environmental Science, Northeast Agricultural University, Harbin, China
| | - Xing Zeng
- College of Agronomy, Northeast Agricultural University, Harbin, China
| | - Yuhang Zhu
- College of Resources and Environmental Science, Northeast Agricultural University, Harbin, China
| | - Wei Wang
- College of Resources and Environmental Science, Northeast Agricultural University, Harbin, China
| | - Siqi Huang
- College of Resources and Environmental Science, Northeast Agricultural University, Harbin, China
| | - Xinxin Qiao
- College of Resources and Environmental Science, Northeast Agricultural University, Harbin, China
| | - Zhenhua Wang
- College of Agronomy, Northeast Agricultural University, Harbin, China
| | - Hong Di
- College of Agronomy, Northeast Agricultural University, Harbin, China
| | - Juanjuan Qu
- College of Resources and Environmental Science, Northeast Agricultural University, Harbin, China
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Shibata Y, Takahashi T, Morimoto T, Kanai M, Fujii T, Akao T, Goshima T, Yamada T. Quantitative stability of the folates highly accumulated in a non-Kyokai sake yeast. J GEN APPL MICROBIOL 2021; 67:214-219. [PMID: 34373370 DOI: 10.2323/jgam.2021.03.002] [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] [Indexed: 11/03/2022]
Abstract
Pressed sake cake, a by-product of sake brewing, is a rich dietary source of folates, which are important vitamins for humans. However, considerable losses of folates occur during storage and cooking. We have previously reported that Km67, the house sake yeast strain of Kiku-masamune sake brewery, can accumulate high folate levels. In this study, we found that the folate content of pressed sake cakes produced with Km67 remained at approximately their maximum level after the fermentation activity stopped. To elucidate the mechanisms of high folate accumulation in Km67, we analyzed the expression of 23 folate-metabolizing genes. The expression of ABZ1 and FOL3 was almost always higher in Km67 than in Kyokai no. 701 yeast (K701), which suggested that enhanced expression of the genes involved in folate biosynthesis was a mechanism of high folate accumulation in Km67. We found that the folates of Km67 pressed sake cakes were quantitatively stable at 4°C under refrigerated storage conditions. In addition, the homocysteine content of Km67 pressed sake cakes was almost always higher than that of K701 pressed sake cakes. This result suggests that a reason for high folate accumulation in Km67 yeast is the need to reduce the intracellular concentration of homocysteine. Our results provide biologically meaningful information on folate metabolism in yeast.
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Affiliation(s)
- Yusuke Shibata
- General Research Laboratory, Kiku-Masamune Sake Brewing Co. Ltd
| | | | | | | | | | | | | | - Tasuku Yamada
- General Research Laboratory, Kiku-Masamune Sake Brewing Co. Ltd
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4
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Dikkala PK, Usmani Z, Kumar S, Gupta VK, Bhargava A, Sharma M. Fungal Production of Vitamins and Their Food Industrial Applications. Fungal Biol 2021. [DOI: 10.1007/978-3-030-85603-8_16] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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5
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Zeng W, Niu L, Wang Z, Wang X, Wang Y, Pan L, Lu Z, Cui G, Weng W, Wang M, Meng X, Wang Z. Application of an antibody chip for screening differentially expressed proteins during peach ripening and identification of a metabolon in the SAM cycle to generate a peach ethylene biosynthesis model. HORTICULTURE RESEARCH 2020; 7:31. [PMID: 32194967 PMCID: PMC7072073 DOI: 10.1038/s41438-020-0249-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Revised: 11/27/2019] [Accepted: 01/07/2020] [Indexed: 05/21/2023]
Abstract
Peach (Prunus persica) is a typical climacteric fruit that produces ethylene rapidly during ripening, and its fruit softens quickly. Stony hard peach cultivars, however, do not produce large amounts of ethylene, and the fruit remains firm until fully ripe, thus differing from melting flesh peach cultivars. To identify the key proteins involved in peach fruit ripening, an antibody-based proteomic analysis was conducted. A mega-monoclonal antibody (mAb) library was generated and arrayed on a chip (mAbArray) at a high density, covering ~4950 different proteins of peach. Through the screening of peach fruit proteins with the mAbArray chip, differentially expressed proteins recognized by 1587 mAbs were identified, and 33 corresponding antigens were ultimately identified by immunoprecipitation and mass spectrometry. These proteins included not only important enzymes involved in ethylene biosynthesis, such as ACO1, SAHH, SAMS, and MetE, but also novel factors such as NUDT2. Furthermore, protein-protein interaction analysis identified a metabolon containing SAHH and MetE. By combining the antibody-based proteomic data with the transcriptomic and metabolic data, a mathematical model of ethylene biosynthesis in peach was constructed. Simulation results showed that MetE is an important regulator during peach ripening, partially through interaction with SAHH.
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Affiliation(s)
- Wenfang Zeng
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, 450009 Zhengzhou, China
| | - Liang Niu
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, 450009 Zhengzhou, China
| | | | - Xiaobei Wang
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, 450009 Zhengzhou, China
| | - Yan Wang
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, 450009 Zhengzhou, China
| | - Lei Pan
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, 450009 Zhengzhou, China
| | - Zhenhua Lu
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, 450009 Zhengzhou, China
| | - Guochao Cui
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, 450009 Zhengzhou, China
| | | | | | - Xun Meng
- Abmart, 200233 Shanghai, China
- Northwest University, 710127 Xi’an, China
| | - Zhiqiang Wang
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, 450009 Zhengzhou, China
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Deobald D, Hanna R, Shahryari S, Layer G, Adrian L. Identification and characterization of a bacterial core methionine synthase. Sci Rep 2020; 10:2100. [PMID: 32034217 PMCID: PMC7005905 DOI: 10.1038/s41598-020-58873-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 01/20/2020] [Indexed: 11/18/2022] Open
Abstract
Methionine synthases are essential enzymes for amino acid and methyl group metabolism in all domains of life. Here, we describe a putatively anciently derived type of methionine synthase yet unknown in bacteria, here referred to as core-MetE. The enzyme appears to represent a minimal MetE form and transfers methyl groups from methylcobalamin instead of methyl-tetrahydrofolate to homocysteine. Accordingly, it does not possess the tetrahydrofolate binding domain described for canonical bacterial MetE proteins. In Dehalococcoides mccartyi strain CBDB1, an obligate anaerobic, mesophilic, slowly growing organohalide-respiring bacterium, it is encoded by the locus cbdbA481. In line with the observation to not accept methyl groups from methyl-tetrahydrofolate, all known genomes of bacteria of the class Dehalococcoidia lack metF encoding for methylene-tetrahydrofolate reductase synthesizing methyl-tetrahydrofolate, but all contain a core-metE gene. We heterologously expressed core-MetECBDB in E. coli and purified the 38 kDa protein. Core-MetECBDB exhibited Michaelis-Menten kinetics with respect to methylcob(III)alamin (KM ≈ 240 µM) and L-homocysteine (KM ≈ 50 µM). Only methylcob(III)alamin was found to be active as methyl donor with a kcat ≈ 60 s-1. Core-MetECBDB did not functionally complement metE-deficient E. coli strain DH5α (ΔmetE::kan) suggesting that core-MetECBDB and the canonical MetE enzyme from E. coli have different enzymatic specificities also in vivo. Core-MetE appears to be similar to a MetE-ancestor evolved before LUCA (last universal common ancestor) using methylated cobalamins as methyl donor whereas the canonical MetE consists of a tandem repeat and might have evolved by duplication of the core-MetE and diversification of the N-terminal part to a tetrahydrofolate-binding domain.
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Affiliation(s)
- Darja Deobald
- Leipzig University, Institute of Biochemistry, Brüderstraße 34, 04103, Leipzig, Germany
- Helmholtz Centre for Environmental Research - UFZ, Isotope Biogeochemistry, Permoserstraße 15, 04318, Leipzig, Germany
| | - Rafael Hanna
- Leipzig University, Institute of Biochemistry, Brüderstraße 34, 04103, Leipzig, Germany
- Freiburg University, Institute of Pharmaceutical Sciences, Stefan-Meier-Straße 19, 79104, Freiburg im Breisgau, Germany
| | - Shahab Shahryari
- Helmholtz Centre for Environmental Research - UFZ, Isotope Biogeochemistry, Permoserstraße 15, 04318, Leipzig, Germany
| | - Gunhild Layer
- Leipzig University, Institute of Biochemistry, Brüderstraße 34, 04103, Leipzig, Germany
- Freiburg University, Institute of Pharmaceutical Sciences, Stefan-Meier-Straße 19, 79104, Freiburg im Breisgau, Germany
| | - Lorenz Adrian
- Helmholtz Centre for Environmental Research - UFZ, Isotope Biogeochemistry, Permoserstraße 15, 04318, Leipzig, Germany.
- Technische Universität Berlin, Chair of Geobiotechnology, Ackerstraße 76, 13355, Berlin, Germany.
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Design, synthesis and biological activity of N 5-substituted tetrahydropteroate analogs as non-classical antifolates against cobalamin-dependent methionine synthase and potential anticancer agents. Eur J Med Chem 2020; 190:112113. [PMID: 32058237 DOI: 10.1016/j.ejmech.2020.112113] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 01/28/2020] [Accepted: 01/31/2020] [Indexed: 12/16/2022]
Abstract
Cobalamin-dependent methionine synthase (MetH) is involved in the process of tumor cell growth and survival. In this study, a novel series of N5-electrophilic substituted tetrahydropteroate analogs without glutamate residue were designed as non-classical antifolates and evaluated for their inhibitory activities against MetH. In addition, the cytotoxicity of target compounds was evaluated in human tumor cell lines. With N5-chloracetyl as the optimum group, further structure research on the benzene substituent and on the 2,4-diamino group was also performed. Compound 6c, with IC50 value of 12.1 μM against MetH and 0.16-6.12 μM against five cancer cells, acted as competitive inhibitor of MetH. Flow cytometry studies indicated that compound 6c arrested HL-60 cells in the G1-phase and then inducted late apoptosis. The molecular docking further explained the structure-activity relationship.
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8
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Structure-guided function discovery of an NRPS-like glycine betaine reductase for choline biosynthesis in fungi. Proc Natl Acad Sci U S A 2019; 116:10348-10353. [PMID: 31061132 DOI: 10.1073/pnas.1903282116] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Nonribosomal peptide synthetases (NRPSs) and NRPS-like enzymes have diverse functions in primary and secondary metabolisms. By using a structure-guided approach, we uncovered the function of a NRPS-like enzyme with unusual domain architecture, catalyzing two sequential two-electron reductions of glycine betaine to choline. Structural analysis based on the homology model suggests cation-π interactions as the major substrate specificity determinant, which was verified using substrate analogs and inhibitors. Bioinformatic analysis indicates this NRPS-like glycine betaine reductase is highly conserved and widespread in kingdom fungi. Genetic knockout experiments confirmed its role in choline biosynthesis and maintaining glycine betaine homeostasis in fungi. Our findings demonstrate that the oxidative choline-glycine betaine degradation pathway can operate in a fully reversible fashion and provide insight in understanding fungal choline metabolism. The use of an NRPS-like enzyme for reductive choline formation is energetically efficient compared with known pathways. Our discovery also underscores the capabilities of the structure-guided approach in assigning functions of uncharacterized multidomain proteins, which can potentially aid functional discovery of new enzymes by genome mining.
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9
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Sahu U, Rajendra VKH, Kapnoor SS, Bhagavat R, Chandra N, Rangarajan PN. Methionine synthase is localized to the nucleus in Pichia pastoris and Candida albicans and to the cytoplasm in Saccharomyces cerevisiae. J Biol Chem 2017; 292:14730-14746. [PMID: 28701466 DOI: 10.1074/jbc.m117.783019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 07/10/2017] [Indexed: 11/06/2022] Open
Abstract
Methionine synthase (MS) catalyzes methylation of homocysteine, the last step in the biosynthesis of methionine, which is essential for the regeneration of tetrahydrofolate and biosynthesis of S-adenosylmethionine. Here, we report that MS is localized to the nucleus of Pichia pastoris and Candida albicans but is cytoplasmic in Saccharomyces cerevisiae The P. pastoris strain carrying a deletion of the MET6 gene encoding MS (Ppmet6) exhibits methionine as well as adenine auxotrophy indicating that MS is required for methionine as well as adenine biosynthesis. Nuclear localization of P. pastoris MS (PpMS) was abrogated by the deletion of 107 C-terminal amino acids or the R742A mutation. In silico analysis of the PpMS structure indicated that PpMS may exist in a dimer-like configuration in which Arg-742 of a monomer forms a salt bridge with Asp-113 of another monomer. Biochemical studies indicate that R742A as well as D113R mutations abrogate nuclear localization of PpMS and its ability to reverse methionine auxotrophy of Ppmet6 Thus, association of two PpMS monomers through the interaction of Arg-742 and Asp-113 is essential for catalytic activity and nuclear localization. When PpMS is targeted to the cytoplasm employing a heterologous nuclear export signal, it is expressed at very low levels and is unable to reverse methionine and adenine auxotrophy of Ppmet6 Thus, nuclear localization is essential for the stability and function of MS in P. pastoris. We conclude that nuclear localization of MS is a unique feature of respiratory yeasts such as P. pastoris and C. albicans, and it may have novel moonlighting functions in the nucleus.
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Affiliation(s)
- Umakant Sahu
- From the Department of Biochemistry, Indian Institute of Science, Bangalore 560012, India
| | - Vinod K H Rajendra
- From the Department of Biochemistry, Indian Institute of Science, Bangalore 560012, India
| | - Shankar S Kapnoor
- From the Department of Biochemistry, Indian Institute of Science, Bangalore 560012, India
| | - Raghu Bhagavat
- From the Department of Biochemistry, Indian Institute of Science, Bangalore 560012, India
| | - Nagasuma Chandra
- From the Department of Biochemistry, Indian Institute of Science, Bangalore 560012, India
| | - Pundi N Rangarajan
- From the Department of Biochemistry, Indian Institute of Science, Bangalore 560012, India
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Exploration of Sulfur Assimilation of Aspergillus fumigatus Reveals Biosynthesis of Sulfur-Containing Amino Acids as a Virulence Determinant. Infect Immun 2016; 84:917-929. [PMID: 26787716 DOI: 10.1128/iai.01124-15] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 01/07/2016] [Indexed: 12/17/2022] Open
Abstract
Fungal infections are of major relevance due to the increased numbers of immunocompromised patients, frequently delayed diagnosis, and limited therapeutics. To date, the growth and nutritional requirements of fungi during infection, which are relevant for invasion of the host, are poorly understood. This is particularly true for invasive pulmonary aspergillosis, as so far, sources of (macro)elements that are exploited during infection have been identified to only a limited extent. Here, we have investigated sulfur (S) utilization by the human-pathogenic mold Aspergillus fumigatus during invasive growth. Our data reveal that inorganic S compounds or taurine is unlikely to serve as an S source during invasive pulmonary aspergillosis since a sulfate transporter mutant strain and a sulfite reductase mutant strain are fully virulent. In contrast, the S-containing amino acid cysteine is limiting for fungal growth, as proven by the reduced virulence of a cysteine auxotroph. Moreover, phenotypic characterization of this strain further revealed the robustness of the subordinate glutathione redox system. Interestingly, we demonstrate that methionine synthase is essential for A. fumigatus virulence, defining the biosynthetic route of this proteinogenic amino acid as a potential antifungal target. In conclusion, we provide novel insights into the nutritional requirements ofA. fumigatus during pathogenesis, a prerequisite to understanding and fighting infection.
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11
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Zou H, Chen N, Shi M, Xian M, Song Y, Liu J. The metabolism and biotechnological application of betaine in microorganism. Appl Microbiol Biotechnol 2016; 100:3865-76. [PMID: 27005411 DOI: 10.1007/s00253-016-7462-3] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 03/08/2016] [Accepted: 03/09/2016] [Indexed: 11/29/2022]
Abstract
Glycine betaine (betaine) is widely distributed in nature and can be found in many microorganisms, including bacteria, archaea, and fungi. Due to its particular functions, many microorganisms utilize betaine as a functional chemical and have evolved different metabolic pathways for the biosynthesis and catabolism of betaine. As in animals and plants, the principle role of betaine is to protect microbial cells against drought, osmotic stress, and temperature stress. In addition, the role of betaine in methyl group metabolism has been observed in a variety of microorganisms. Recent studies have shown that betaine supplementation can improve the performance of microbial strains used for the fermentation of lactate, ethanol, lysine, pyruvate, and vitamin B12, during which betaine can act as stress protectant or methyl donor for the biosynthesis of structurally complex compounds. In this review, we summarize the transport, synthesis, catabolism, and functions of betaine in microorganisms and discuss potential engineering strategies that employ betaine as a methyl donor for the biosynthesis of complex secondary metabolites such as a variety of vitamins, coenzymes, and antibiotics. In conclusion, the biocompatibility, C/N ratio, abundance, and comprehensive metabolic information of betaine collectively indicate that this molecule has great potential for broad applications in microbial biotechnology.
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Affiliation(s)
- Huibin Zou
- College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, 266042, China. .,CAS Key Laboratory of Bio-based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China.
| | - Ningning Chen
- College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, 266042, China
| | - Mengxun Shi
- College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, 266042, China
| | - Mo Xian
- CAS Key Laboratory of Bio-based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
| | - Yimin Song
- College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, 266042, China
| | - Junhong Liu
- College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, 266042, China
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12
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Schmoll M, Dattenböck C, Carreras-Villaseñor N, Mendoza-Mendoza A, Tisch D, Alemán MI, Baker SE, Brown C, Cervantes-Badillo MG, Cetz-Chel J, Cristobal-Mondragon GR, Delaye L, Esquivel-Naranjo EU, Frischmann A, Gallardo-Negrete JDJ, García-Esquivel M, Gomez-Rodriguez EY, Greenwood DR, Hernández-Oñate M, Kruszewska JS, Lawry R, Mora-Montes HM, Muñoz-Centeno T, Nieto-Jacobo MF, Nogueira Lopez G, Olmedo-Monfil V, Osorio-Concepcion M, Piłsyk S, Pomraning KR, Rodriguez-Iglesias A, Rosales-Saavedra MT, Sánchez-Arreguín JA, Seidl-Seiboth V, Stewart A, Uresti-Rivera EE, Wang CL, Wang TF, Zeilinger S, Casas-Flores S, Herrera-Estrella A. The Genomes of Three Uneven Siblings: Footprints of the Lifestyles of Three Trichoderma Species. Microbiol Mol Biol Rev 2016; 80:205-327. [PMID: 26864432 PMCID: PMC4771370 DOI: 10.1128/mmbr.00040-15] [Citation(s) in RCA: 121] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The genus Trichoderma contains fungi with high relevance for humans, with applications in enzyme production for plant cell wall degradation and use in biocontrol. Here, we provide a broad, comprehensive overview of the genomic content of these species for "hot topic" research aspects, including CAZymes, transport, transcription factors, and development, along with a detailed analysis and annotation of less-studied topics, such as signal transduction, genome integrity, chromatin, photobiology, or lipid, sulfur, and nitrogen metabolism in T. reesei, T. atroviride, and T. virens, and we open up new perspectives to those topics discussed previously. In total, we covered more than 2,000 of the predicted 9,000 to 11,000 genes of each Trichoderma species discussed, which is >20% of the respective gene content. Additionally, we considered available transcriptome data for the annotated genes. Highlights of our analyses include overall carbohydrate cleavage preferences due to the different genomic contents and regulation of the respective genes. We found light regulation of many sulfur metabolic genes. Additionally, a new Golgi 1,2-mannosidase likely involved in N-linked glycosylation was detected, as were indications for the ability of Trichoderma spp. to generate hybrid galactose-containing N-linked glycans. The genomic inventory of effector proteins revealed numerous compounds unique to Trichoderma, and these warrant further investigation. We found interesting expansions in the Trichoderma genus in several signaling pathways, such as G-protein-coupled receptors, RAS GTPases, and casein kinases. A particularly interesting feature absolutely unique to T. atroviride is the duplication of the alternative sulfur amino acid synthesis pathway.
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Affiliation(s)
- Monika Schmoll
- Austrian Institute of Technology, Department Health and Environment, Bioresources Unit, Tulln, Austria
| | - Christoph Dattenböck
- Austrian Institute of Technology, Department Health and Environment, Bioresources Unit, Tulln, Austria
| | | | | | - Doris Tisch
- Research Division Biotechnology and Microbiology, Institute of Chemical Engineering, TU Wien, Vienna, Austria
| | - Mario Ivan Alemán
- Cinvestav, Department of Genetic Engineering, Irapuato, Guanajuato, Mexico
| | - Scott E Baker
- Pacific Northwest National Laboratory, Richland, Washington, USA
| | - Christopher Brown
- University of Otago, Department of Biochemistry and Genetics, Dunedin, New Zealand
| | | | - José Cetz-Chel
- LANGEBIO, National Laboratory of Genomics for Biodiversity, Cinvestav-Irapuato, Guanajuato, Mexico
| | | | - Luis Delaye
- Cinvestav, Department of Genetic Engineering, Irapuato, Guanajuato, Mexico
| | | | - Alexa Frischmann
- Research Division Biotechnology and Microbiology, Institute of Chemical Engineering, TU Wien, Vienna, Austria
| | | | - Monica García-Esquivel
- LANGEBIO, National Laboratory of Genomics for Biodiversity, Cinvestav-Irapuato, Guanajuato, Mexico
| | | | - David R Greenwood
- The University of Auckland, School of Biological Sciences, Auckland, New Zealand
| | - Miguel Hernández-Oñate
- LANGEBIO, National Laboratory of Genomics for Biodiversity, Cinvestav-Irapuato, Guanajuato, Mexico
| | - Joanna S Kruszewska
- Polish Academy of Sciences, Institute of Biochemistry and Biophysics, Laboratory of Fungal Glycobiology, Warsaw, Poland
| | - Robert Lawry
- Lincoln University, Bio-Protection Research Centre, Lincoln, Canterbury, New Zealand
| | | | | | | | | | | | | | - Sebastian Piłsyk
- Polish Academy of Sciences, Institute of Biochemistry and Biophysics, Laboratory of Fungal Glycobiology, Warsaw, Poland
| | - Kyle R Pomraning
- Pacific Northwest National Laboratory, Richland, Washington, USA
| | - Aroa Rodriguez-Iglesias
- Austrian Institute of Technology, Department Health and Environment, Bioresources Unit, Tulln, Austria
| | | | | | - Verena Seidl-Seiboth
- Research Division Biotechnology and Microbiology, Institute of Chemical Engineering, TU Wien, Vienna, Austria
| | | | | | - Chih-Li Wang
- National Chung-Hsing University, Department of Plant Pathology, Taichung, Taiwan
| | - Ting-Fang Wang
- Academia Sinica, Institute of Molecular Biology, Taipei, Taiwan
| | - Susanne Zeilinger
- Research Division Biotechnology and Microbiology, Institute of Chemical Engineering, TU Wien, Vienna, Austria University of Innsbruck, Institute of Microbiology, Innsbruck, Austria
| | | | - Alfredo Herrera-Estrella
- LANGEBIO, National Laboratory of Genomics for Biodiversity, Cinvestav-Irapuato, Guanajuato, Mexico
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Wheatley RW, Ng KK, Kapoor M. Fungal cobalamin-independent methionine synthase: Insights from the model organism, Neurospora crassa. Arch Biochem Biophys 2016; 590:125-137. [DOI: 10.1016/j.abb.2015.11.037] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 11/10/2015] [Accepted: 11/21/2015] [Indexed: 10/22/2022]
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Bromke MA, Hesse H. Phylogenetic analysis of methionine synthesis genes from Thalassiosira pseudonana. SPRINGERPLUS 2015; 4:391. [PMID: 26251775 PMCID: PMC4523565 DOI: 10.1186/s40064-015-1163-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 07/17/2015] [Indexed: 02/08/2023]
Abstract
Diatoms are unicellular algae responsible for approximately 20% of global carbon fixation. Their evolution by secondary endocytobiosis resulted in a complex cellular structure and metabolism compared to algae with primary plastids. The sulfate assimilation and methionine synthesis pathways provide S-containing amino acids for the synthesis of proteins and a range of metabolites such as dimethylsulfoniopropionate. To obtain an insight into the localization and organization of the sulfur metabolism pathways we surveyed the genome of Thalassiosira pseudonana-a model organism for diatom research. We have identified and annotated genes for enzymes involved in respective pathways. Protein localization was predicted using similarities to known signal peptide motifs. We performed detailed phylogenetic analyses of enzymes involved in sulfate uptake/reduction and methionine metabolism. Moreover, we have found in up-stream sequences of studied diatoms methionine biosynthesis genes a conserved motif, which shows similarity to the Met31, a cis-motif regulating expression of methionine biosynthesis genes in yeast.
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Affiliation(s)
- Mariusz A Bromke
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany
| | - Holger Hesse
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany
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15
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Interplay between Gliotoxin Resistance, Secretion, and the Methyl/Methionine Cycle in Aspergillus fumigatus. EUKARYOTIC CELL 2015; 14:941-57. [PMID: 26150413 DOI: 10.1128/ec.00055-15] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 06/30/2015] [Indexed: 01/20/2023]
Abstract
Mechanistic studies on gliotoxin biosynthesis and self-protection in Aspergillus fumigatus, both of which require the gliotoxin oxidoreductase GliT, have revealed a rich landscape of highly novel biochemistries, yet key aspects of this complex molecular architecture remain obscure. Here we show that an A. fumigatus ΔgliA strain is completely deficient in gliotoxin secretion but still retains the ability to efflux bisdethiobis(methylthio)gliotoxin (BmGT). This correlates with a significant increase in sensitivity to exogenous gliotoxin because gliotoxin trapped inside the cell leads to (i) activation of the gli cluster, as disabling gli cluster activation, via gliZ deletion, attenuates the sensitivity of an A. fumigatus ΔgliT strain to gliotoxin, thus implicating cluster activation as a factor in gliotoxin sensitivity, and (ii) increased methylation activity due to excess substrate (dithiol gliotoxin) for the gliotoxin bis-thiomethyltransferase GtmA. Intracellular dithiol gliotoxin is oxidized by GliT and subsequently effluxed by GliA. In the absence of GliA, gliotoxin persists in the cell and is converted to BmGT, with levels significantly higher than those in the wild type. Similarly, in the ΔgliT strain, gliotoxin oxidation is impeded, and methylation occurs unchecked, leading to significant S-adenosylmethionine (SAM) depletion and S-adenosylhomocysteine (SAH) overproduction. This in turn significantly contributes to the observed hypersensitivity of gliT-deficient A. fumigatus to gliotoxin. Our observations reveal a key role for GliT in preventing dysregulation of the methyl/methionine cycle to control intracellular SAM and SAH homeostasis during gliotoxin biosynthesis and exposure. Moreover, we reveal attenuated GliT abundance in the A. fumigatus ΔgliK strain, but not the ΔgliG strain, following exposure to gliotoxin, correlating with relative sensitivities. Overall, we illuminate new systems interactions that have evolved in gliotoxin-producing, compared to gliotoxin-naive, fungi to facilitate their cellular presence.
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Saint-Macary ME, Barbisan C, Gagey MJ, Frelin O, Beffa R, Lebrun MH, Droux M. Methionine biosynthesis is essential for infection in the rice blast fungus Magnaporthe oryzae. PLoS One 2015; 10:e0111108. [PMID: 25856162 PMCID: PMC4391826 DOI: 10.1371/journal.pone.0111108] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Accepted: 09/29/2014] [Indexed: 02/02/2023] Open
Abstract
Methionine is a sulfur amino acid standing at the crossroads of several biosynthetic pathways. In fungi, the last step of methionine biosynthesis is catalyzed by a cobalamine-independent methionine synthase (Met6, EC 2.1.1.14). In the present work, we studied the role of Met6 in the infection process of the rice blast fungus, Magnaporthe oryzae. To this end MET6 null mutants were obtained by targeted gene replacement. On minimum medium, MET6 null mutants were auxotrophic for methionine. Even when grown in presence of excess methionine, these mutants displayed developmental defects, such as reduced mycelium pigmentation, aerial hypha formation and sporulation. They also displayed characteristic metabolic signatures such as increased levels of cysteine, cystathionine, homocysteine, S-adenosylmethionine, S-adenosylhomocysteine while methionine and glutathione levels remained unchanged. These metabolic perturbations were associated with the over-expression of MgCBS1 involved in the reversed transsulfuration pathway that metabolizes homocysteine into cysteine and MgSAM1 and MgSAHH1 involved in the methyl cycle. This suggests a physiological adaptation of M. oryzae to metabolic defects induced by the loss of Met6, in particular an increase in homocysteine levels. Pathogenicity assays showed that MET6 null mutants were non-pathogenic on both barley and rice leaves. These mutants were defective in appressorium-mediated penetration and invasive infectious growth. These pathogenicity defects were rescued by addition of exogenous methionine and S-methylmethionine. These results show that M. oryzae cannot assimilate sufficient methionine from plant tissues and must synthesize this amino acid de novo to fulfill its sulfur amino acid requirement during infection.
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Affiliation(s)
| | - Crystel Barbisan
- Biochemistry Department, Bayer CropScience, F-69263, Lyon, France
| | - Marie Josèphe Gagey
- UMR 5240 MAP, UMR 5240 CNRS-UCB-INSA-BCS, Bayer CropScience, F-69263, Lyon, France
| | - Océane Frelin
- UMR 5240 MAP, UMR 5240 CNRS-UCB-INSA-BCS, Bayer CropScience, F-69263, Lyon, France
| | - Roland Beffa
- Biochemistry Department, Bayer CropScience, F-69263, Lyon, France
| | - Marc Henri Lebrun
- UMR 5240 MAP, UMR 5240 CNRS-UCB-INSA-BCS, Bayer CropScience, F-69263, Lyon, France
- * E-mail:
| | - Michel Droux
- UMR 5240 MAP, UMR 5240 CNRS-UCB-INSA-BCS, Bayer CropScience, F-69263, Lyon, France
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17
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Inhibitors of amino acids biosynthesis as antifungal agents. Amino Acids 2014; 47:227-49. [PMID: 25408465 PMCID: PMC4302243 DOI: 10.1007/s00726-014-1873-1] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 11/05/2014] [Indexed: 12/22/2022]
Abstract
Fungal microorganisms, including the human pathogenic yeast and filamentous fungi, are able to synthesize all proteinogenic amino acids, including nine that are essential for humans. A number of enzymes catalyzing particular steps of human-essential amino acid biosynthesis are fungi specific. Numerous studies have shown that auxotrophic mutants of human pathogenic fungi impaired in biosynthesis of particular amino acids exhibit growth defect or at least reduced virulence under in vivo conditions. Several chemical compounds inhibiting activity of one of these enzymes exhibit good antifungal in vitro activity in minimal growth media, which is not always confirmed under in vivo conditions. This article provides a comprehensive overview of the present knowledge on pathways of amino acids biosynthesis in fungi, with a special emphasis put on enzymes catalyzing particular steps of these pathways as potential targets for antifungal chemotherapy.
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Fu J, Zhang X, Chen X, Yin Y, Ma Z. Serine O-acetyltransferase is important, but not essential for cysteine-methionine synthesis in Fusarium graminearum. World J Microbiol Biotechnol 2013; 30:1219-28. [PMID: 24197784 DOI: 10.1007/s11274-013-1544-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Accepted: 10/24/2013] [Indexed: 11/29/2022]
Abstract
O-acetyltransferase (SAT) is a key enzyme converting serine into O-acetylserine in the synthesis of sulphur-containing amino acids. To characterize the function of FgSAT in Fusarium graminearum, three deletion mutants of FgSAT (ΔFgSAT-1, -2 and -18) were obtained using a gene replacement strategy. The three mutants did not show recognizable phenotypic changes on potato dextrose agar medium, but exhibited a very weak growth on fructose gelatin agar (FGA) medium containing SO₄²⁻ as sole sulfur source. Supplementation of O-acetylserine, cysteine, or methionine, but not serine, rescued the defect of mycelial growth in FgSAT deletion mutants, indicating that FgSAT is involved in conversion of serine into O-acetylserine. The three mutants had a decrease in conidiation in mung bean liquid, but not in carboxymethyl cellulose. Virulence, deoxynivalenol production and fungicide sensitivity assays found that the three mutants showed no significant difference from wild-type progenitor PH-1. Real-time PCR assays detected an increase in expression levels of FgOAHS, FgCBS and FgCGL genes involved in the alternative pathway in FgSAT deletion mutants, suggesting that the alternative pathway in F. graminearum is present and can operate. Addition of homoserine, the upstream substrate of the alternative pathway, also restored the normal mycelial growth of FgSAT deletion mutants on FGA, indicating that the alternative pathway in F. graminearum might be positively regulated by homoserine.
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Affiliation(s)
- Jing Fu
- Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China,
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19
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Fu J, Wu J, Jiang J, Wang Z, Ma Z. Cystathionine gamma-synthase is essential for methionine biosynthesis in Fusarium graminearum. Fungal Biol 2013; 117:13-21. [DOI: 10.1016/j.funbio.2012.11.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2012] [Revised: 09/18/2012] [Accepted: 11/08/2012] [Indexed: 11/16/2022]
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20
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Fu TM, Almqvist J, Liang YH, Li L, Huang Y, Su XD. Crystal structures of cobalamin-independent methionine synthase (MetE) from Streptococcus mutans: a dynamic zinc-inversion model. J Mol Biol 2011; 412:688-97. [PMID: 21840320 DOI: 10.1016/j.jmb.2011.08.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Revised: 08/01/2011] [Accepted: 08/02/2011] [Indexed: 11/17/2022]
Abstract
Cobalamin-independent methionine synthase (MetE) catalyzes the direct transfer of a methyl group from methyltetrahydrofolate to l-homocysteine to form methionine. Previous studies have shown that the MetE active site coordinates a zinc atom, which is thought to act as a Lewis acid and plays a role in the activation of thiol. Extended X-ray absorption fine structure studies and mutagenesis experiments identified the zinc-binding site in MetE from Escherichia coli. Further structural investigations of MetE from Thermotoga maritima lead to the proposition of two models: "induced fit" and "dynamic equilibrium", to account for the catalytic mechanisms of MetE. Here, we present crystal structures of oxidized and zinc-replete MetE from Streptococcus mutans at the physiological pH. The structures reveal that zinc is mobile in the active center and has the possibility to invert even in the absence of homocysteine. These structures provide evidence for the dynamic equilibrium model.
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Affiliation(s)
- Tian-Min Fu
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, PR China
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21
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Sieńko M, Natorff R, Owczarek S, Olewiecki I, Paszewski A. Aspergillus nidulans genes encoding reverse transsulfuration enzymes belong to homocysteine regulon. Curr Genet 2009; 55:561-70. [PMID: 19685245 DOI: 10.1007/s00294-009-0269-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2009] [Revised: 07/29/2009] [Accepted: 07/31/2009] [Indexed: 11/26/2022]
Abstract
Homocysteine is an intermediate in methionine synthesis in Aspergillus nidulans, but it can also be converted to cysteine by the reverse transsulfuration pathway involving cystathionine beta-synthase (CBS) and cystathionine gamma-lyase (CGL). Because homocysteine is toxic to the cell at high concentrations, this pathway also functions as a means of removal of its excess. We found that the transcription of the mecA and mecB genes encoding CBS and CGL was upregulated by excess of homocysteine as well as by shortage of cysteine. Homocysteine induced transcription of both genes when added to the growth medium or overproduced in a regulatory mutant. The derepressing effect of cysteine shortage was observed in some mutants and in the wild-type strain during sulfur starvation. An increase in the level of mecA or mecB transcript roughly parallel with the elevation of the respective enzyme activity. On the basis of the mode of mecA and mecB regulation by homocysteine, these genes may be classified in a group of genes upregulated directly or indirectly by this amino acid. We call this group of genes the "homocysteine regulon".
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Affiliation(s)
- Marzena Sieńko
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 5A Pawińskiego Str, 02-106, Warsaw, Poland.
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22
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Turło J, Gutkowska B, Herold F, Krzyczkowski W, Błażewicz A, Kocjan R. Optimizing vitamin B12 biosynthesis by mycelial cultures of Lentinula edodes (Berk.) Pegl. Enzyme Microb Technol 2008. [DOI: 10.1016/j.enzmictec.2008.05.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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23
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Metabolism of Methionine in Plants and Phototrophic Bacteria. SULFUR METABOLISM IN PHOTOTROPHIC ORGANISMS 2008. [DOI: 10.1007/978-1-4020-6863-8_5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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24
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Suliman HS, Appling DR, Robertus JD. The gene for cobalamin-independent methionine synthase is essential in Candida albicans: a potential antifungal target. Arch Biochem Biophys 2007; 467:218-26. [PMID: 17935688 DOI: 10.1016/j.abb.2007.09.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2007] [Revised: 08/29/2007] [Accepted: 09/02/2007] [Indexed: 11/24/2022]
Abstract
Methionine synthase catalyzes the transfer of a methyl group from tetrahydrofolate to homocysteine to produce methionine. Although mammalian enzymes are cobalamin-dependent, fungal methionine synthases are cobalamin-independent. The opportunistic pathogen Candida albicans is a diploid and carries two copies of the methionine synthase gene, MET6. Homologous recombination was used to disrupt a single MET6 gene. MET6/met6 knock-outs, deleted with either the URA3 or ARG4 cassette, grew as well as the wild-type strain. However, we were unable to obtain a viable met6/met6 deletion strain, even on media supplemented with exogenous methionine. This suggests that methionine synthase is essential to C. albicans. To explore this further, a C. albicans strain was constructed in which one MET6 locus was deleted and the second placed under a regulatable promoter. The conditional mutant grew well under inducing conditions, even in the absence of methionine. It would not grow under repressing conditions in the absence of methionine, but would grow when the media was supplemented with exogenous methionine. A Western blot showed that a small amount of enzyme was expressed under repressing conditions. Taken together, these data reveal that methionine is necessary for growth of C. albicans, but not sufficient-a minimal level of methionine synthase expression is required, perhaps to limit homocysteine toxicity. Furthermore, these results suggest that cobalamin-independent methionine synthase is a plausible target for the design of antifungal agents.
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Affiliation(s)
- Huda S Suliman
- Institute of Cellular and Molecular Biology, Department of Chemistry and Biochemistry, University of Texas, Austin, TX 78712, USA
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25
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Sieńko M, Natorff R, Zieliński Z, Hejduk A, Paszewski A. Two Aspergillus nidulans genes encoding methylenetetrahydrofolate reductases are up-regulated by homocysteine. Fungal Genet Biol 2006; 44:691-700. [PMID: 17257865 DOI: 10.1016/j.fgb.2006.12.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2006] [Revised: 12/05/2006] [Accepted: 12/05/2006] [Indexed: 10/23/2022]
Abstract
Methylenetetrahydrofolate reductase (MTHFR) catalyzes the reduction of 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate, a co-substrate in the synthesis of methionine from homocysteine. We have cloned and characterized two Aspergillus nidulans genes encoding MTHFRs: metA and metF. Mutations in either gene result in methionine requirement; the metA-encoded enzyme is responsible for only 10-15% of total MTHFR activity. These two enzymes belong to different classes of MTHFRs. Mutations in metA but not in the metF gene are suppressed by mutations resulting in enhancement of homocysteine synthesis. The expression of both genes is up-regulated by homocysteine.
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Affiliation(s)
- Marzena Sieńko
- Institute of Biochemistry and Biophysics, PAS, Department of Genetics, 5A Pawińskiego Str, 02-106 Warszawa, Poland.
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26
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Barra L, Fontenelle C, Ermel G, Trautwetter A, Walker GC, Blanco C. Interrelations between glycine betaine catabolism and methionine biosynthesis in Sinorhizobium meliloti strain 102F34. J Bacteriol 2006; 188:7195-204. [PMID: 17015658 PMCID: PMC1636217 DOI: 10.1128/jb.00208-06] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Methionine is produced by methylation of homocysteine. Sinorhizobium meliloti 102F34 possesses only one methionine synthase, which catalyzes the transfer of a methyl group from methyl tetrahydrofolate to homocysteine. This vitamin B(12)-dependent enzyme is encoded by the metH gene. Glycine betaine can also serve as an alternative methyl donor for homocysteine. This reaction is catalyzed by betaine-homocysteine methyl transferase (BHMT), an enzyme that has been characterized in humans and rats. An S. meliloti gene whose product is related to the human BHMT enzyme has been identified and named bmt. This enzyme is closely related to mammalian BHMTs but has no homology with previously described bacterial betaine methyl transferases. Glycine betaine inhibits the growth of an S. meliloti bmt mutant in low- and high-osmotic strength media, an effect that correlates with a decrease in the catabolism of glycine betaine. This inhibition was not observed with other betaines, like homobetaine, dimethylsulfoniopropionate, and trigonelline. The addition of methionine to the growth medium allowed a bmt mutant to recover growth despite the presence of glycine betaine. Methionine also stimulated glycine betaine catabolism in a bmt strain, suggesting the existence of another catabolic pathway. Inactivation of metH or bmt did not affect the nodulation efficiency of the mutants in the 102F34 strain background. Nevertheless, a metH strain was severely defective in competing with the wild-type strain in a coinoculation experiment.
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Affiliation(s)
- Lise Barra
- Osmorégulation chez les bactéries, UMR CNRS 6026, Université de Rennes I, Campus de Beaulieu, Av. du Général Leclerc, 35042 Rennes, France
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Kumar A, John L, Alam M, Gupta A, Sharma G, Pillai B, Sengupta S. Homocysteine- and cysteine-mediated growth defect is not associated with induction of oxidative stress response genes in yeast. Biochem J 2006; 396:61-9. [PMID: 16433631 PMCID: PMC1449999 DOI: 10.1042/bj20051411] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Intracellular thiols like cysteine, homocysteine and glutathione play a critical role in the regulation of important cellular processes. Alteration of intracellular thiol concentration results in many diseased states; for instance, elevated levels of homocysteine are considered to be an independent risk factor for cardiovascular disease. Yeast has proved to be an excellent model system for studying many human diseases since it carries homologues of nearly 40% of human disease genes and many fundamental pathways are highly conserved between the two organisms. In the present study, we demonstrate that cysteine and homocysteine, but not glutathione, inhibit yeast growth in a concentration-dependent manner. Using deletion strains (str2Delta and str4Delta) we show that cysteine and homocysteine independently inhibit yeast growth. Transcriptional profiling of yeast treated with cysteine and homocysteine revealed that genes coding for antioxidant enzymes like glutathione peroxidase, catalase and superoxide dismutase were down-regulated. Furthermore, transcriptional response to homocysteine did not show any similarity to the response to H2O2. We also failed to detect induction of reactive oxygen species in homocysteine- and cysteine-treated cells, using fluorogenic probes. These results indicate that homocysteine- and cysteine-induced growth defect is not due to the oxidative stress. However, we found an increase in the expression of KAR2 (karyogamy 2) gene, a well-known marker of ER (endoplasmic reticulum) stress and also observed HAC1 cleavage in homocysteine- and cysteinetreated cells, which indicates that homocysteine- and cysteine-mediated growth defect may probably be attributed to ER stress. Transcriptional profiling also revealed that genes involved in one-carbon metabolism, glycolysis and serine biosynthesis were up-regulated on exogenous addition of cysteine and homocysteine, suggesting that cells try to reduce the intracellular concentration of thiols by up-regulating the genes involved in their metabolism.
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Affiliation(s)
- Arun Kumar
- Institute of Genomics and Integrative Biology, Mall Road, Delhi-110007, India
| | - Lijo John
- Institute of Genomics and Integrative Biology, Mall Road, Delhi-110007, India
| | - Md. Mahmood Alam
- Institute of Genomics and Integrative Biology, Mall Road, Delhi-110007, India
| | - Ankit Gupta
- Institute of Genomics and Integrative Biology, Mall Road, Delhi-110007, India
| | - Gayatri Sharma
- Institute of Genomics and Integrative Biology, Mall Road, Delhi-110007, India
| | - Beena Pillai
- Institute of Genomics and Integrative Biology, Mall Road, Delhi-110007, India
- Correspondence may be addressed to either of the authors (email or )
| | - Shantanu Sengupta
- Institute of Genomics and Integrative Biology, Mall Road, Delhi-110007, India
- Correspondence may be addressed to either of the authors (email or )
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28
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Krömer JO, Heinzle E, Schröder H, Wittmann C. Accumulation of homolanthionine and activation of a novel pathway for isoleucine biosynthesis in Corynebacterium glutamicum McbR deletion strains. J Bacteriol 2006; 188:609-18. [PMID: 16385051 PMCID: PMC1347288 DOI: 10.1128/jb.188.2.609-618.2006] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In the present work, the metabolic consequences of the deletion of the methionine and cysteine biosynthesis repressor protein (McbR) in Corynebacterium glutamicum, which releases almost all enzymes of methionine biosynthesis and sulfate assimilation from transcriptional regulation (D. A. Rey, A. Pühler, and J. Kalinowski, J. Biotechnol. 103:51-65, 2003), were studied. C. glutamicum ATCC 13032 DeltamcbR showed no overproduction of methionine. Metabolome analysis revealed drastic accumulation of a single metabolite, which was not present in the wild type. It was identified by isotopic labeling studies and gas chromatography/mass spectrometry as L-homolanthionine {S-[(3S)-3-amino-3-carboxypropyl]-L-homocysteine}. The accumulation of homolanthionine to an intracellular concentration of 130 mM in the DeltamcbR strain was accompanied by an elevated intracellular homocysteine level. It was shown that cystathionine-gamma-synthase (MetB) produced homolanthionine as a side reaction. MetB showed higher substrate affinity for cysteine (Km = 260 microM) than for homocysteine (Km = 540 microM). The cell is able to cleave homolanthionine at low rates via cystathionine-beta-lyase (MetC). This cleavage opens a novel threonine-independent pathway for isoleucine biosynthesis via 2-oxobutanoate formed by MetC. In fact, the deletion mutant exhibited an increased intracellular isoleucine level. Metabolic flux analysis of C. glutamicum DeltamcbR revealed that only 24% of the O-acetylhomoserine at the entry of the methionine pathway is utilized for methionine biosynthesis; the dominating fraction is either stored as homolanthionine or redirected towards the formation of isoleucine. Deletion of metB completely prevents homolanthionine accumulation, which is regarded as an important step in the development of C. glutamicum strains for biotechnological methionine production.
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Affiliation(s)
- Jens Olaf Krömer
- Biochemical Engineering, Saarland University, P.O. Box 151150, 66123 Saarbrücken, Germany
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29
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Gophna U, Bapteste E, Doolittle WF, Biran D, Ron EZ. Evolutionary plasticity of methionine biosynthesis. Gene 2005; 355:48-57. [PMID: 16046084 DOI: 10.1016/j.gene.2005.05.028] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2005] [Accepted: 05/17/2005] [Indexed: 11/25/2022]
Abstract
Methionine is an essential cellular constituent, the initiator of protein synthesis and a precursor in many metabolic activities, such as methylation and formylation. Here we investigate the genomic distribution of the methionine biosynthetic pathway and analyze its evolutionary history by reconstructing the phylogeny of its enzymatic components. We demonstrate the evolutionary complexity of methionine synthesis and describe the various mechanisms that have shaped this biosynthetic pathway: gene duplication, functional reassignment, lateral acquisition and gene loss. Lateral gene transfer within and between domains and gene recruitment have played an important role in the evolution of this pathway, especially in its first and third enzymatic steps--homoserine activation and homocysteine methylation. These analyses are also the basis of predictions regarding methionine synthesis in Archaea, where the pathway is yet to be characterized. This study illustrates how diverse molecular solutions can fulfill a conserved function in living beings.
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Affiliation(s)
- Uri Gophna
- Genome Atlantic and Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada B3H 1X5.
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Seong K, Hou Z, Tracy M, Kistler HC, Xu JR. Random Insertional Mutagenesis Identifies Genes Associated with Virulence in the Wheat Scab Fungus Fusarium graminearum. PHYTOPATHOLOGY 2005; 95:744-750. [PMID: 18943005 DOI: 10.1094/phyto-95-0744] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
ABSTRACT Fusarium graminearum is an important pathogen of small grains and maize in many areas of the world. To better understand the molecular mechanisms of F. graminearum pathogenesis, we used the restriction enzyme-mediated integration (REMI) approach to generate random insertional mutants. Eleven pathogenicity mutants were identified by screening 6,500 hygromycin-resistant transformants. Genetic analyses indicated that the defects in plant infection were tagged by the transforming vector in six of these mutants. In mutant M8, the transforming plasmid was integrated 110-bp upstream from the start codon of the cystathionine betalyase gene (CBL1). Gene replacement mutants deleted for CBL1 and the methionine synthase gene MSY1 were also obtained. Both the cbl1 and msy1 deletion mutants were methionine auxotrophic and significantly reduced in virulence on corn silks and wheat heads. We also identified genes disrupted by the transforming DNA in three other REMI mutants exhibiting reduced virulence. In mutants M68, the transforming vectors were inserted in the NADH: ubiquinone oxidoreductase. The putative b-ZIP transcription factor gene and the transducin beta-subunit-like gene disrupted in mutants M7 and M75, respectively, had no known homologs in filamentous fungi and were likely to be novel fungal virulence factors.
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Pascon RC, Ganous TM, Kingsbury JM, Cox GM, McCusker JH. Cryptococcus neoformans methionine synthase: expression analysis and requirement for virulence. Microbiology (Reading) 2004; 150:3013-3023. [PMID: 15347759 DOI: 10.1099/mic.0.27235-0] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
This paper describes (i) the expression profile of the methionine synthase gene (MET6) in the human pathogenic fungus Cryptococcus neoformans and (ii) the phenotypes of a C. neoformans met6 mutant. In contrast to the MET3 gene, which showed no significant change in expression in any environmental condition tested, the MET6 gene showed a substantial induction in response to methionine and a dramatic transcriptional induction in response to homocysteine. Like a met3 mutant, the met6 mutant was a methionine auxotroph. However, relative to a met3 mutant, the met6 mutant grew very slowly and was less heat-shock resistant. In contrast to a met3 mutant, the met6 mutant lost viability when starved of methionine, and it was deficient in capsule formation. Like a met3 mutant, the met6 mutant was avirulent. In contrast to a met3 mutant, the met6 mutant was hypersensitive to fluconazole and to the calcineurin inhibitors FK506 and cyclosporin A. A synergistic fungicidal effect was also found between each of these drugs and met6. The phenotypic differences between the met3 and met6 mutants may be due to the accumulation in met6 mutants of homocysteine, a toxic metabolic intermediate that inhibits sterol biosynthesis.
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Affiliation(s)
- Renata C Pascon
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Tonya M Ganous
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Joanne M Kingsbury
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Gary M Cox
- Department of Medicine, Infectious Disease Division, Duke University Medical Center, Durham, NC 27710, USA
| | - John H McCusker
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
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Ferrer JL, Ravanel S, Robert M, Dumas R. Crystal structures of cobalamin-independent methionine synthase complexed with zinc, homocysteine, and methyltetrahydrofolate. J Biol Chem 2004; 279:44235-8. [PMID: 15326182 DOI: 10.1074/jbc.c400325200] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cobalamin-independent methionine synthase (MetE) catalyzes the synthesis of methionine by a direct transfer of the methyl group of N5-methyltetrahydrofolate (CH3-H2PteGlun) to the sulfur atom of homocysteine (Hcy). We report here the first crystal structure of this metalloenzyme under different forms, free or complexed with the Hcy and folate substrates. The Arabidopsis thaliana MetE (AtMetE) crystals reveal a monomeric structure built by two (betaalpha)8 barrels making a deep groove at their interface. The active site is located at the surface of the C-terminal domain, facing the large interdomain cleft. Inside the active site, His647, Cys649, and Cys733 are involved in zinc coordination, whereas Asp605, Ile437, and Ser439 interact with Hcy. Opposite the zinc/Hcy binding site, a cationic loop (residues 507-529) belonging to the C-terminal domain anchors the first glutamyl residue of CH3-H4PteGlu5. The pterin moiety of CH3-H4PteGlu5 is stacked with Trp567, enabling the N5-methyl group to protrude in the direction of the zinc atom. These data suggest a structural role of the N-terminal domain of AtMetE in the stabilization of loop 507-529 and in the interaction with the poly-glutamate chain of CH3-H4PteGlun. Comparison of AtMetE structures reveals that the addition of Hcy does not lead to a direct coordination of the sulfur atom with zinc but to a reorganization of the zinc binding site with a stronger coordination to Cys649, Cys733, and a water molecule.
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Affiliation(s)
- Jean-Luc Ferrer
- Laboratoire de Cristallogenèse et Cristallographie des Protéines, Institut de Biologie Structurale J.-P. Ebel, 41 rue Jules Horowitz, 38027 Grenoble 1, France.
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Lao JI, Beyer K, Ariza A. The homocysteine pathway: A new target for Alzheimer disease treatment? Drug Dev Res 2004. [DOI: 10.1002/ddr.10360] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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