1
|
Paredes-Barrada M, Kopsiaftis P, Claassens NJ, van Kranenburg R. Parageobacillus thermoglucosidasius as an emerging thermophilic cell factory. Metab Eng 2024; 83:39-51. [PMID: 38490636 DOI: 10.1016/j.ymben.2024.03.001] [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: 12/18/2023] [Revised: 02/21/2024] [Accepted: 03/05/2024] [Indexed: 03/17/2024]
Abstract
Parageobacillus thermoglucosidasius is a thermophilic and facultatively anaerobic microbe, which is emerging as one of the most promising thermophilic model organisms for metabolic engineering. The use of thermophilic microorganisms for industrial bioprocesses provides the advantages of increased reaction rates and reduced cooling costs for bioreactors compared to their mesophilic counterparts. Moreover, it enables starch or lignocellulose degradation and fermentation to occur at the same temperature in a Simultaneous Saccharification and Fermentation (SSF) or Consolidated Bioprocessing (CBP) approach. Its natural hemicellulolytic capabilities and its ability to convert CO to metabolic energy make P. thermoglucosidasius a potentially attractive host for bio-based processes. It can effectively degrade hemicellulose due to a number of hydrolytic enzymes, carbohydrate transporters, and regulatory elements coded from a genomic cluster named Hemicellulose Utilization (HUS) locus. The growing availability of effective genetic engineering tools in P. thermoglucosidasius further starts to open up its potential as a versatile thermophilic cell factory. A number of strain engineering examples showcasing the potential of P. thermoglucosidasius as a microbial chassis for the production of bulk and fine chemicals are presented along with current research bottlenecks. Ultimately, this review provides a holistic overview of the distinct metabolic characteristics of P. thermoglucosidasius and discusses research focused on expanding the native metabolic boundaries for the development of industrially relevant strains.
Collapse
Affiliation(s)
- Miguel Paredes-Barrada
- Laboratory of Microbiology, Wageningen University, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
| | | | - Nico J Claassens
- Laboratory of Microbiology, Wageningen University, Stippeneng 4, 6708 WE, Wageningen, The Netherlands.
| | - Richard van Kranenburg
- Laboratory of Microbiology, Wageningen University, Stippeneng 4, 6708 WE, Wageningen, The Netherlands; Corbion, Arkelsedijk 46, 4206 AC, Gorinchem, The Netherlands.
| |
Collapse
|
2
|
Kim JY, Lee M, Oh S, Kang B, Yasin M, Chang IS. Acetogen and acetogenesis for biological syngas valorization. BIORESOURCE TECHNOLOGY 2023; 384:129368. [PMID: 37343794 DOI: 10.1016/j.biortech.2023.129368] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 06/15/2023] [Accepted: 06/17/2023] [Indexed: 06/23/2023]
Abstract
The bioconversion of syngas using (homo)acetogens as biocatalysts shows promise as a viable option due to its higher selectivity and milder reaction conditions compared to thermochemical conversion. The current bioconversion process operates primarily to produce C2 chemicals (e.g., acetate and ethanol) with sufficient technology readiness levels (TRLs) in process engineering (as midstream) and product purification (as downstream). However, the economic feasibility of this process could be improved with greater biocatalytic options in the upstream phase. This review focuses on the Wood-Ljungdahl pathway (WLP) which is a biological syngas-utilization pathway, redox balance and ATP generation, suggesting that the use of a specific biocatalysts including Eubacterium limosum could be advantageous in syngas valorization. A pertinent strategy to mainly produce chemicals with a high degree of reduction is also provided with examples of flux control, mixed cultivation and mixotrophy. Finally, this article presents future direction of industrial utilization of syngas fermentation.
Collapse
Affiliation(s)
- Ji-Yeon Kim
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology, 123 Cheomdan-gwagiro, Buk-gu, Gwangju 61005, Republic of Korea; Research Center for Innovative Energy and Carbon Optimized Synthesis for Chemicals (inn-ECOSysChem), Gwangju Institute of Science and Technology, 123 Cheomdan-gwagiro, Buk-gu, Gwangju 61005, Republic of Korea
| | - Mungyu Lee
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology, 123 Cheomdan-gwagiro, Buk-gu, Gwangju 61005, Republic of Korea; Research Center for Innovative Energy and Carbon Optimized Synthesis for Chemicals (inn-ECOSysChem), Gwangju Institute of Science and Technology, 123 Cheomdan-gwagiro, Buk-gu, Gwangju 61005, Republic of Korea
| | - Soyoung Oh
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology, 123 Cheomdan-gwagiro, Buk-gu, Gwangju 61005, Republic of Korea
| | - Byeongchan Kang
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology, 123 Cheomdan-gwagiro, Buk-gu, Gwangju 61005, Republic of Korea
| | - Muhammad Yasin
- Department of Chemical Engineering, COMSATS University Islamabad, Lahore Campus, Pakistan
| | - In Seop Chang
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology, 123 Cheomdan-gwagiro, Buk-gu, Gwangju 61005, Republic of Korea; Research Center for Innovative Energy and Carbon Optimized Synthesis for Chemicals (inn-ECOSysChem), Gwangju Institute of Science and Technology, 123 Cheomdan-gwagiro, Buk-gu, Gwangju 61005, Republic of Korea.
| |
Collapse
|
3
|
Sheng L, Madika A, Lau MSH, Zhang Y, Minton NP. Metabolic engineering for the production of acetoin and 2,3-butanediol at elevated temperature in Parageobacillus thermoglucosidasius NCIMB 11955. Front Bioeng Biotechnol 2023; 11:1191079. [PMID: 37200846 PMCID: PMC10185769 DOI: 10.3389/fbioe.2023.1191079] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 04/20/2023] [Indexed: 05/20/2023] Open
Abstract
The current climate crisis has emphasised the need to achieve global net-zero by 2050, with countries being urged to set considerable emission reduction targets by 2030. Exploitation of a fermentative process that uses a thermophilic chassis can represent a way to manufacture chemicals and fuels through more environmentally friendly routes with a net reduction in greenhouse gas emissions. In this study, the industrially relevant thermophile Parageobacillus thermoglucosidasius NCIMB 11955 was engineered to produce 3-hydroxybutanone (acetoin) and 2,3-butanediol (2,3-BDO), organic compounds with commercial applications. Using heterologous acetolactate synthase (ALS) and acetolactate decarboxylase (ALD) enzymes, a functional 2,3-BDO biosynthetic pathway was constructed. The formation of by-products was minimized by the deletion of competing pathways surrounding the pyruvate node. Redox imbalance was addressed through autonomous overexpression of the butanediol dehydrogenase and by investigating appropriate aeration levels. Through this, we were able to produce 2,3-BDO as the predominant fermentation metabolite, with up to 6.6 g/L 2,3-BDO (0.33 g/g glucose) representing 66% of the theoretical maximum at 50°C. In addition, the identification and subsequent deletion of a previously unreported thermophilic acetoin degradation gene (acoB1) resulted in enhanced acetoin production under aerobic conditions, producing 7.6 g/L (0.38 g/g glucose) representing 78% of the theoretical maximum. Furthermore, through the generation of a ΔacoB1 mutant and by testing the effect of glucose concentration on 2,3-BDO production, we were able to produce 15.6 g/L of 2,3-BDO in media supplemented with 5% glucose, the highest titre of 2,3-BDO produced in Parageobacillus and Geobacillus species to date.
Collapse
Affiliation(s)
- Lili Sheng
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, Biodiscovery Institute, The University of Nottingham, Nottingham, United Kingdom
| | - Abubakar Madika
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, Biodiscovery Institute, The University of Nottingham, Nottingham, United Kingdom
- Department of Microbiology, Faculty of Life Sciences, Ahmadu Bello University, Zaria, Nigeria
| | - Matthew S. H. Lau
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, Biodiscovery Institute, The University of Nottingham, Nottingham, United Kingdom
| | - Ying Zhang
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, Biodiscovery Institute, The University of Nottingham, Nottingham, United Kingdom
| | - Nigel P. Minton
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, Biodiscovery Institute, The University of Nottingham, Nottingham, United Kingdom
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust, The University of Nottingham, Nottingham, United Kingdom
- *Correspondence: Nigel P. Minton,
| |
Collapse
|
4
|
Wu L, Zhang L. Biochemical and Functional Characterization of an Iron-Containing Alcohol Dehydrogenase from Thermococcus barophilus Ch5. Appl Biochem Biotechnol 2022; 194:5537-5555. [DOI: 10.1007/s12010-022-04052-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/24/2022] [Indexed: 11/29/2022]
|
5
|
Cho HY, Nam MS, Hong HJ, Song WS, Yoon SI. Structural and Biochemical Analysis of the Furan Aldehyde Reductase YugJ from Bacillus subtilis. Int J Mol Sci 2022; 23:ijms23031882. [PMID: 35163804 PMCID: PMC8836905 DOI: 10.3390/ijms23031882] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 01/29/2022] [Accepted: 02/04/2022] [Indexed: 02/05/2023] Open
Abstract
NAD(H)/NADP(H)-dependent aldehyde/alcohol oxidoreductase (AAOR) participates in a wide range of physiologically important cellular processes by reducing aldehydes or oxidizing alcohols. Among AAOR substrates, furan aldehyde is highly toxic to microorganisms. To counteract the toxic effect of furan aldehyde, some bacteria have evolved AAOR that converts furan aldehyde into a less toxic alcohol. Based on biochemical and structural analyses, we identified Bacillus subtilis YugJ as an atypical AAOR that reduces furan aldehyde. YugJ displayed high substrate specificity toward 5-hydroxymethylfurfural (HMF), a furan aldehyde, in an NADPH- and Ni2+-dependent manner. YugJ folds into a two-domain structure consisting of a Rossmann-like domain and an α-helical domain. YugJ interacts with NADP and Ni2+ using the interdomain cleft of YugJ. A comparative analysis of three YugJ structures indicated that NADP(H) binding plays a key role in modulating the interdomain dynamics of YugJ. Noticeably, a nitrate ion was found in proximity to the nicotinamide ring of NADP in the YugJ structure, and the HMF-reducing activity of YugJ was inhibited by nitrate, providing insights into the substrate-binding mode of YugJ. These findings contribute to the characterization of the YugJ-mediated furan aldehyde reduction mechanism and to the rational design of improved furan aldehyde reductases for the biofuel industry.
Collapse
Affiliation(s)
- Hye Yeon Cho
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon 24341, Korea; (H.Y.C.); (M.S.N.); (H.J.H.)
| | - Mi Sun Nam
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon 24341, Korea; (H.Y.C.); (M.S.N.); (H.J.H.)
| | - Ho Jeong Hong
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon 24341, Korea; (H.Y.C.); (M.S.N.); (H.J.H.)
| | - Wan Seok Song
- Institute of Bioscience and Biotechnology, Kangwon National University, Chuncheon 24341, Korea
- Correspondence: (W.S.S.); (S.-i.Y.)
| | - Sung-il Yoon
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon 24341, Korea; (H.Y.C.); (M.S.N.); (H.J.H.)
- Institute of Bioscience and Biotechnology, Kangwon National University, Chuncheon 24341, Korea
- Correspondence: (W.S.S.); (S.-i.Y.)
| |
Collapse
|
6
|
Hitschler L, Nissen LS, Kuntz M, Basen M. Alcohol dehydrogenases AdhE and AdhB with broad substrate ranges are important enzymes for organic acid reduction in Thermoanaerobacter sp. strain X514. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:187. [PMID: 34563250 PMCID: PMC8466923 DOI: 10.1186/s13068-021-02038-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 09/08/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND The industrial production of various alcohols from organic carbon compounds may be performed at high rates and with a low risk of contamination using thermophilic microorganisms as whole-cell catalysts. Thermoanaerobacter species that thrive around 50-75 °C not only perform fermentation of sugars to alcohols, but some also utilize different organic acids as electron acceptors, reducing them to their corresponding alcohols. RESULTS We purified AdhE as the major NADH- and AdhB as the major NADPH-dependent alcohol dehydrogenase (ADH) from the cell extract of the organic acid-reducing Thermoanaerobacter sp. strain X514. Both enzymes were present in high amounts during growth on glucose with and without isobutyrate, had broad substrate spectra including different aldehydes, with high affinities (< 1 mM) for acetaldehyde and for NADH (AdhE) or NADPH (AdhB). Both enzymes were highly thermostable at the physiological temperature of alcohol production. In addition to AdhE and AdhB, we identified two abundant AdhA-type ADHs based on their genes, which were recombinantly produced and biochemically characterized. The other five ADHs encoded in the genome were only expressed at low levels. CONCLUSIONS According to their biochemical and kinetic properties, AdhE and AdhB are most important for ethanol formation from sugar and reduction of organic acids to alcohols, while the role of the two AdhA-type enzymes is less clear. AdhE is the only abundant aldehyde dehydrogenase for the acetyl-CoA reduction to aldehydes, however, acid reduction may also proceed directly by aldehyde:ferredoxin oxidoreductase. The role of the latter in bio-alcohol formation from sugar and in organic acid reduction needs to be elucidated in future studies.
Collapse
Affiliation(s)
- Lisa Hitschler
- Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University Frankfurt/Main, Max-von-Laue Str. 9, 60438, Frankfurt/Main, Germany
- Department of Membrane Biochemistry, Life and Medical Sciences (LIMES) Institute, University of Bonn, Carl-Troll-Straße 31, 53115, Bonn, Germany
| | - Laura Sofie Nissen
- Microbiology, Institute of Biological Sciences, University of Rostock, Albert-Einstein Str. 3, 18059, Rostock, Germany
| | - Michelle Kuntz
- Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University Frankfurt/Main, Max-von-Laue Str. 9, 60438, Frankfurt/Main, Germany
- Interfaculty Institute for Microbiology and Infection Medicine Tübingen, University of Tübingen, Auf der Morgenstelle 24, 72076, Tübingen, Germany
| | - Mirko Basen
- Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University Frankfurt/Main, Max-von-Laue Str. 9, 60438, Frankfurt/Main, Germany.
- Microbiology, Institute of Biological Sciences, University of Rostock, Albert-Einstein Str. 3, 18059, Rostock, Germany.
| |
Collapse
|
7
|
Zhang L, Jiang D, Li Y, Wu L, Liu Q, Dong K, Oger P. Characterization of a novel type III alcohol dehydrogenase from Thermococcus barophilus Ch5. Int J Biol Macromol 2021; 171:491-501. [PMID: 33428959 DOI: 10.1016/j.ijbiomac.2020.12.197] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 12/25/2020] [Accepted: 12/26/2020] [Indexed: 12/27/2022]
Abstract
The genome of the hyperthermophilic and piezophilic euryarchaeaon Thermococcus barophilus Ch5 encodes three putative alcohol dehydrogenases (Tba ADHs). Herein, we characterized Tba ADH547 biochemically and probed its catalytic mechanism by mutational studies. Our data demonstrate that Tba ADH547 can oxidize ethanol and reduce acetaldehyde at high temperature with the same optimal temperature (75 °C) and exhibit similar thermostability for oxidization and reduction reactions. However, Tba ADH547 has different optimal pH for oxidation and reduction: 8.5 for oxidation and 7.0 for reduction. Tba ADH547 is dependent on a divalent ion for its oxidation activity, among which Mn2+ is optimal. However, Tba ADH547 displays about 20% reduction activity without a divalent ion, and the maximal activity with Fe2+. Furthermore, Tba ADH547 showcases a strong substrate preference for 1-butanol and 1-hexanol over ethanol and other alcohols. Similarly, Tba ADH547 prefers butylaldehyde to acetaldehyde as its reduction substrate. Mutational studies showed that the mutations of residues D195, H199, H262 and H274 to Ala result in the significant activity loss of Tba ADH547, suggesting that residues D195, H199, H262 and H274 are responsible for catalysis. Overall, Tba ADH547 is a thermoactive ADH with novel biochemical characteristics, thereby allowing this enzyme to be a potential biocatalyst.
Collapse
Affiliation(s)
- Likui Zhang
- Guangling College, Yangzhou University, China; College of Environmental Science and Engineering, Marine Science & Technology Institute, Yangzhou University, China.
| | - Donghao Jiang
- College of Environmental Science and Engineering, Marine Science & Technology Institute, Yangzhou University, China
| | - Yuting Li
- College of Environmental Science and Engineering, Marine Science & Technology Institute, Yangzhou University, China
| | - Leilei Wu
- College of Environmental Science and Engineering, Marine Science & Technology Institute, Yangzhou University, China
| | - Qing Liu
- College of Environmental Science and Engineering, Marine Science & Technology Institute, Yangzhou University, China
| | - Kunming Dong
- College of Environmental Science and Engineering, Marine Science & Technology Institute, Yangzhou University, China
| | - Philippe Oger
- Univ Lyon, INSA de Lyon, CNRS UMR 5240, Villeurbanne, France.
| |
Collapse
|
8
|
Katsyv A, Müller V. Overcoming Energetic Barriers in Acetogenic C1 Conversion. Front Bioeng Biotechnol 2020; 8:621166. [PMID: 33425882 PMCID: PMC7793690 DOI: 10.3389/fbioe.2020.621166] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Accepted: 11/19/2020] [Indexed: 11/13/2022] Open
Abstract
Currently one of the biggest challenges for society is to combat global warming. A solution to this global threat is the implementation of a CO2-based bioeconomy and a H2-based bioenergy economy. Anaerobic lithotrophic bacteria such as the acetogenic bacteria are key players in the global carbon and H2 cycle and thus prime candidates as driving forces in a H2- and CO2-bioeconomy. Naturally, they convert two molecules of CO2via the Wood-Ljungdahl pathway (WLP) to one molecule of acetyl-CoA which can be converted to different C2-products (acetate or ethanol) or elongated to C4 (butyrate) or C5-products (caproate). Since there is no net ATP generation from acetate formation, an electron-transport phosphorylation (ETP) module is hooked up to the WLP. ETP provides the cell with additional ATP, but the ATP gain is very low, only a fraction of an ATP per mol of acetate. Since acetogens live at the thermodynamic edge of life, metabolic engineering to obtain high-value products is currently limited by the low energy status of the cells that allows for the production of only a few compounds with rather low specificity. To set the stage for acetogens as production platforms for a wide range of bioproducts from CO2, the energetic barriers have to be overcome. This review summarizes the pathway, the energetics of the pathway and describes ways to overcome energetic barriers in acetogenic C1 conversion.
Collapse
Affiliation(s)
- Alexander Katsyv
- Department of Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Frankfurt am Main, Germany
| | - Volker Müller
- Department of Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Frankfurt am Main, Germany
| |
Collapse
|
9
|
Azmi L, Bragginton EC, Cadby IT, Byron O, Roe AJ, Lovering AL, Gabrielsen M. High-resolution structure of the alcohol dehydrogenase domain of the bifunctional bacterial enzyme AdhE. Acta Crystallogr F Struct Biol Commun 2020; 76:414-421. [PMID: 32880589 PMCID: PMC7470043 DOI: 10.1107/s2053230x20010237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 07/23/2020] [Indexed: 11/13/2023] Open
Abstract
The bifunctional alcohol/aldehyde dehydrogenase (AdhE) comprises both an N-terminal aldehyde dehydrogenase (AldDH) and a C-terminal alcohol dehydrogenase (ADH). In vivo, full-length AdhE oligomerizes into long oligomers known as spirosomes. However, structural analysis of AdhE is challenging owing to the heterogeneity of the spirosomes. Therefore, the domains of AdhE are best characterized separately. Here, the structure of ADH from the pathogenic Escherichia coli O157:H7 was determined to 1.65 Å resolution. The dimeric crystal structure was confirmed in solution by small-angle X-ray scattering.
Collapse
Affiliation(s)
- Liyana Azmi
- Institute of Infection, Immunity and Inflammation, University of Glasgow, University Avenue, Glasgow G12 8QQ, United Kingdom
| | - Eilis C Bragginton
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Ian T Cadby
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Olwyn Byron
- Institute of Infection, Immunity and Inflammation, University of Glasgow, University Avenue, Glasgow G12 8QQ, United Kingdom
| | - Andrew J Roe
- Institute of Infection, Immunity and Inflammation, University of Glasgow, University Avenue, Glasgow G12 8QQ, United Kingdom
| | - Andrew L Lovering
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Mads Gabrielsen
- CRUK Beatson Institute, Switchback Road, Glasgow G61 1BD, United Kingdom
| |
Collapse
|
10
|
Filamentation of the bacterial bi-functional alcohol/aldehyde dehydrogenase AdhE is essential for substrate channeling and enzymatic regulation. Nat Commun 2020; 11:1426. [PMID: 32188856 PMCID: PMC7080775 DOI: 10.1038/s41467-020-15214-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 02/26/2020] [Indexed: 11/08/2022] Open
Abstract
Acetaldehyde-alcohol dehydrogenase (AdhE) enzymes are a key metabolic enzyme in bacterial physiology and pathogenicity. They convert acetyl-CoA to ethanol via an acetaldehyde intermediate during ethanol fermentation in an anaerobic environment. This two-step reaction is associated to NAD+ regeneration, essential for glycolysis. The bifunctional AdhE enzyme is conserved in all bacterial kingdoms but also in more phylogenetically distant microorganisms such as green microalgae. It is found as an oligomeric form called spirosomes, for which the function remains elusive. Here, we use cryo-electron microscopy to obtain structures of Escherichia coli spirosomes in different conformational states. We show that spirosomes contain active AdhE monomers, and that AdhE filamentation is essential for its activity in vitro and function in vivo. The detailed analysis of these structures provides insight showing that AdhE filamentation is essential for substrate channeling within the filament and for the regulation of enzyme activity.
Collapse
|
11
|
Park CK, Horton NC. Structures, functions, and mechanisms of filament forming enzymes: a renaissance of enzyme filamentation. Biophys Rev 2019; 11:927-994. [PMID: 31734826 PMCID: PMC6874960 DOI: 10.1007/s12551-019-00602-6] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 10/24/2019] [Indexed: 12/19/2022] Open
Abstract
Filament formation by non-cytoskeletal enzymes has been known for decades, yet only relatively recently has its wide-spread role in enzyme regulation and biology come to be appreciated. This comprehensive review summarizes what is known for each enzyme confirmed to form filamentous structures in vitro, and for the many that are known only to form large self-assemblies within cells. For some enzymes, studies describing both the in vitro filamentous structures and cellular self-assembly formation are also known and described. Special attention is paid to the detailed structures of each type of enzyme filament, as well as the roles the structures play in enzyme regulation and in biology. Where it is known or hypothesized, the advantages conferred by enzyme filamentation are reviewed. Finally, the similarities, differences, and comparison to the SgrAI endonuclease system are also highlighted.
Collapse
Affiliation(s)
- Chad K. Park
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ 85721 USA
| | - Nancy C. Horton
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ 85721 USA
| |
Collapse
|
12
|
Kim G, Azmi L, Jang S, Jung T, Hebert H, Roe AJ, Byron O, Song JJ. Aldehyde-alcohol dehydrogenase forms a high-order spirosome architecture critical for its activity. Nat Commun 2019; 10:4527. [PMID: 31586059 PMCID: PMC6778083 DOI: 10.1038/s41467-019-12427-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 09/10/2019] [Indexed: 02/07/2023] Open
Abstract
Aldehyde-alcohol dehydrogenase (AdhE) is a key enzyme in bacterial fermentation, converting acetyl-CoA to ethanol, via two consecutive catalytic reactions. Here, we present a 3.5 Å resolution cryo-EM structure of full-length AdhE revealing a high-order spirosome architecture. The structure shows that the aldehyde dehydrogenase (ALDH) and alcohol dehydrogenase (ADH) active sites reside at the outer surface and the inner surface of the spirosome respectively, thus topologically separating these two activities. Furthermore, mutations disrupting the helical structure abrogate enzymatic activity, implying that formation of the spirosome structure is critical for AdhE activity. In addition, we show that this spirosome structure undergoes conformational change in the presence of cofactors. This work presents the atomic resolution structure of AdhE and suggests that the high-order helical structure regulates its enzymatic activity. Aldehyde-alcohol dehydrogenase (AdhE) converts acetyl-CoA to ethanol and plays an important role in bacterial fermentation. Here the authors present the 3.5 Å cryo-EM structure of full-length E. coli AdhE, which reveals a right-handed helical spirosome structure and they show that the helical structure is required for AdhE activity.
Collapse
Affiliation(s)
- Gijeong Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Korea
| | - Liyana Azmi
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, G12 8QQ, Scotland, UK
| | - Seongmin Jang
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Korea
| | - Taeyang Jung
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Korea.,School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, Novum, SE-141 57, Sweden.,Department of Biosciences and Nutrition, Karolinska Institutet, S-141 83, Huddinge, Sweden
| | - Hans Hebert
- School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, Novum, SE-141 57, Sweden.,Department of Biosciences and Nutrition, Karolinska Institutet, S-141 83, Huddinge, Sweden
| | - Andrew J Roe
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, G12 8QQ, Scotland, UK
| | - Olwyn Byron
- School of Life Sciences, University of Glasgow, Glasgow, G12 8QQ, Scotland, UK
| | - Ji-Joon Song
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Korea.
| |
Collapse
|
13
|
Wushke S, Froese A, Fristensky B, Zhang XL, Spicer V, Krokhin OV, Levin DB, Sparling R. Genomic comparison of facultatively anaerobic and obligatory aerobic Caldibacillus debilis strains GB1 and Tf helps explain physiological differences. Can J Microbiol 2019; 65:421-428. [PMID: 30694700 DOI: 10.1139/cjm-2018-0464] [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: 11/22/2022]
Abstract
Caldibacillus debilis strains GB1 and Tf display distinct phenotypes. Caldibacillus debilis GB1 is capable of anaerobic growth and can synthesize ethanol while C. debilis Tf cannot. Comparison of the GB1 and Tf genome sequences revealed that the genomes were highly similar in gene content and showed a high level of synteny. At the genome scale, there were several large sections of DNA that appeared to be from lateral gene transfer into the GB1 genome. Tf did have unique genetic content but at a much smaller scale: 300 genes in Tf verses 857 genes in GB1 that matched at ≤90% sequence similarity. Gene complement and copy number of genes for the glycolysis, tricarboxylic acid cycle, and electron transport chain pathways were identical in both strains. While Tf is an obligate aerobe, it possesses the gene complement for an anaerobic lifestyle (ldh, ak, pta, adhE, pfl). As a species, other strains of C. debilis should be expected to have the potential for anaerobic growth. Assaying the whole cell lysate for alcohol dehydrogenase activity revealed an approximately 2-fold increase in the enzymatic activity in GB1 when compared with Tf.
Collapse
Affiliation(s)
- Scott Wushke
- a Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Alan Froese
- a Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Brian Fristensky
- b Department Plant Science, University of Manitoba, Winnipeg, MB R3T 6B3, Canada
| | - Xiang Li Zhang
- b Department Plant Science, University of Manitoba, Winnipeg, MB R3T 6B3, Canada
| | - Victor Spicer
- c Department Physics & Astronomy, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Oleg V Krokhin
- d Department of Internal Medicine & Manitoba Centre for Proteomics and Systems Biology, University of Manitoba, Winnipeg, MB R3A 1R9, Canada
| | - David B Levin
- e Department of Biosystems Engineering, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Richard Sparling
- a Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| |
Collapse
|
14
|
Keller MW, Lipscomb GL, Nguyen DM, Crowley AT, Schut GJ, Scott I, Kelly RM, Adams MWW. Ethanol production by the hyperthermophilic archaeon Pyrococcus furiosus by expression of bacterial bifunctional alcohol dehydrogenases. Microb Biotechnol 2017; 10:1535-1545. [PMID: 28194879 PMCID: PMC5658578 DOI: 10.1111/1751-7915.12486] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 10/03/2016] [Accepted: 11/14/2016] [Indexed: 01/25/2023] Open
Abstract
Ethanol is an important target for the renewable production of liquid transportation fuels. It can be produced biologically from pyruvate, via pyruvate decarboxylase, or from acetyl‐CoA, by alcohol dehydrogenase E (AdhE). Thermophilic bacteria utilize AdhE, which is a bifunctional enzyme that contains both acetaldehyde dehydrogenase and alcohol dehydrogenase activities. Many of these organisms also contain a separate alcohol dehydrogenase (AdhA) that generates ethanol from acetaldehyde, although the role of AdhA in ethanol production is typically not clear. As acetyl‐CoA is a key central metabolite that can be generated from a wide range of substrates, AdhE can serve as a single gene fuel module to produce ethanol through primary metabolic pathways. The focus here is on the hyperthermophilic archaeon Pyrococcus furiosus, which grows by fermenting sugar to acetate, CO2 and H2. Previously, by the heterologous expression of adhA from a thermophilic bacterium, P. furiosus was shown to produce ethanol by a novel mechanism from acetate, mediated by AdhA and the native enzyme aldehyde oxidoreductase (AOR). In this study, the AOR gene was deleted from P. furiosus to evaluate ethanol production directly from acetyl‐CoA by heterologous expression of the adhE gene from eight thermophilic bacteria. Only AdhEs from two Thermoanaerobacter strains showed significant activity in cell‐free extracts of recombinant P. furiosus and supported ethanol production in vivo. In the AOR deletion background, the highest amount of ethanol (estimated 61% theoretical yield) was produced when adhE and adhA from Thermoanaerobacter were co‐expressed.
Collapse
Affiliation(s)
- Matthew W Keller
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Gina L Lipscomb
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Diep M Nguyen
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Alexander T Crowley
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Gerrit J Schut
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Israel Scott
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Robert M Kelly
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695, USA
| | - Michael W W Adams
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
| |
Collapse
|
15
|
Liew F, Henstra AM, Kӧpke M, Winzer K, Simpson SD, Minton NP. Metabolic engineering of Clostridium autoethanogenum for selective alcohol production. Metab Eng 2017; 40:104-114. [PMID: 28111249 PMCID: PMC5367853 DOI: 10.1016/j.ymben.2017.01.007] [Citation(s) in RCA: 130] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 11/01/2016] [Accepted: 01/19/2017] [Indexed: 01/27/2023]
Abstract
Gas fermentation using acetogenic bacteria such as Clostridium autoethanogenum offers an attractive route for production of fuel ethanol from industrial waste gases. Acetate reduction to acetaldehyde and further to ethanol via an aldehyde: ferredoxin oxidoreductase (AOR) and alcohol dehydrogenase has been postulated alongside the classic pathway of ethanol formation via a bi-functional aldehyde/alcohol dehydrogenase (AdhE). Here we demonstrate that AOR is critical to ethanol formation in acetogens and inactivation of AdhE led to consistently enhanced autotrophic ethanol production (up to 180%). Using ClosTron and allelic exchange mutagenesis, which was demonstrated for the first time in an acetogen, we generated single mutants as well as double mutants for both aor and adhE isoforms to confirm the role of each gene. The aor1+2 double knockout strain lost the ability to convert exogenous acetate, propionate and butyrate into the corresponding alcohols, further highlighting the role of these enzymes in catalyzing the thermodynamically unfavourable reduction of carboxylic acids into alcohols. 180% improvement in C. autoethanogenum ethanol production via metabolic engineering. Confirmed role of AOR in autotrophic ethanol production of acetogens. Generated both aor and adhE mutants of C. autoethanogenum.. Demonstrated allelic exchange mutagenesis for stable deletions in acetogens. Inactivation of adhE and aor2, but not aor1, improves autotrophic ethanol production.
Collapse
Affiliation(s)
- Fungmin Liew
- BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University Park, The University of Nottingham, Nottingham NG7 2RD, UK; LanzaTech Inc., 8045 Lamon Avenue, Suite 400, Skokie, IL, USA
| | - Anne M Henstra
- BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University Park, The University of Nottingham, Nottingham NG7 2RD, UK
| | - Michael Kӧpke
- LanzaTech Inc., 8045 Lamon Avenue, Suite 400, Skokie, IL, USA
| | - Klaus Winzer
- BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University Park, The University of Nottingham, Nottingham NG7 2RD, UK
| | - Sean D Simpson
- LanzaTech Inc., 8045 Lamon Avenue, Suite 400, Skokie, IL, USA
| | - Nigel P Minton
- BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University Park, The University of Nottingham, Nottingham NG7 2RD, UK.
| |
Collapse
|
16
|
Both adhE and a Separate NADPH-Dependent Alcohol Dehydrogenase Gene, adhA, Are Necessary for High Ethanol Production in Thermoanaerobacterium saccharolyticum. J Bacteriol 2017; 199:JB.00542-16. [PMID: 27849176 DOI: 10.1128/jb.00542-16] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 11/10/2016] [Indexed: 01/01/2023] Open
Abstract
Thermoanaerobacterium saccharolyticum has been engineered to produce ethanol at about 90% of the theoretical maximum yield (2 ethanol molecules per glucose equivalent) and a titer of 70 g/liter. Its ethanol-producing ability has drawn attention to its metabolic pathways, which could potentially be transferred to other organisms of interest. Here, we report that the iron-containing AdhA is important for ethanol production in the high-ethanol strain of T. saccharolyticum (LL1049). A single-gene deletion of adhA in LL1049 reduced ethanol production by ∼50%, whereas multiple gene deletions of all annotated alcohol dehydrogenase genes except adhA and adhE did not affect ethanol production. Deletion of adhA in wild-type T.saccharolyticum reduced NADPH-linked alcohol dehydrogenase (ADH) activity (acetaldehyde-reducing direction) by 93%.IMPORTANCE In this study, we set out to identify the alcohol dehydrogenases necessary for high ethanol production in T. saccharolyticum Based on previous work, we had assumed that adhE was the primary alcohol dehydrogenase gene. Here, we show that both adhA and adhE are needed for high ethanol yield in the engineered strain LL1049. This is the first report showing adhA is important for ethanol production in a native adhA host, which has important implications for achieving higher ethanol yields in other microorganisms.
Collapse
|
17
|
Zhou J, Shao X, Olson DG, Murphy SJL, Tian L, Lynd LR. Determining the roles of the three alcohol dehydrogenases (AdhA, AdhB and AdhE) in Thermoanaerobacter ethanolicus during ethanol formation. J Ind Microbiol Biotechnol 2017; 44:745-757. [PMID: 28078513 DOI: 10.1007/s10295-016-1896-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 12/22/2016] [Indexed: 12/25/2022]
Abstract
Thermoanaerobacter ethanolicus is a promising candidate for biofuel production due to the broad range of substrates it can utilize and its high ethanol yield compared to other thermophilic bacteria, such as Clostridium thermocellum. Three alcohol dehydrogenases, AdhA, AdhB and AdhE, play key roles in ethanol formation. To study their physiological roles during ethanol formation, we deleted them separately and in combination. Previously, it has been thought that both AdhB and AdhE were bifunctional alcohol dehydrogenases. Here we show that AdhE has primarily acetyl-CoA reduction activity (ALDH) and almost no acetaldehyde reduction (ADH) activity, whereas AdhB has no ALDH activity and but high ADH activity. We found that AdhA and AdhB have similar patterns of activity. Interestingly, although deletion of both adhA and adhB reduced ethanol production, a single deletion of either one actually increased ethanol yields by 60-70%.
Collapse
Affiliation(s)
- Jilai Zhou
- Thayer School of Engineering, Dartmouth College, Hanover, NH, USA.,Bioenergy Science Center, Oak Ridge, TN, USA
| | - Xiongjun Shao
- Thayer School of Engineering, Dartmouth College, Hanover, NH, USA.,Bioenergy Science Center, Oak Ridge, TN, USA
| | - Daniel G Olson
- Thayer School of Engineering, Dartmouth College, Hanover, NH, USA.,Bioenergy Science Center, Oak Ridge, TN, USA
| | - Sean Jean-Loup Murphy
- Thayer School of Engineering, Dartmouth College, Hanover, NH, USA.,Bioenergy Science Center, Oak Ridge, TN, USA
| | - Liang Tian
- Thayer School of Engineering, Dartmouth College, Hanover, NH, USA.,Bioenergy Science Center, Oak Ridge, TN, USA
| | - Lee R Lynd
- Thayer School of Engineering, Dartmouth College, Hanover, NH, USA. .,Bioenergy Science Center, Oak Ridge, TN, USA.
| |
Collapse
|
18
|
Gaona-López C, Julián-Sánchez A, Riveros-Rosas H. Diversity and Evolutionary Analysis of Iron-Containing (Type-III) Alcohol Dehydrogenases in Eukaryotes. PLoS One 2016; 11:e0166851. [PMID: 27893862 PMCID: PMC5125639 DOI: 10.1371/journal.pone.0166851] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 11/05/2016] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Alcohol dehydrogenase (ADH) activity is widely distributed in the three domains of life. Currently, there are three non-homologous NAD(P)+-dependent ADH families reported: Type I ADH comprises Zn-dependent ADHs; type II ADH comprises short-chain ADHs described first in Drosophila; and, type III ADH comprises iron-containing ADHs (FeADHs). These three families arose independently throughout evolution and possess different structures and mechanisms of reaction. While types I and II ADHs have been extensively studied, analyses about the evolution and diversity of (type III) FeADHs have not been published yet. Therefore in this work, a phylogenetic analysis of FeADHs was performed to get insights into the evolution of this protein family, as well as explore the diversity of FeADHs in eukaryotes. PRINCIPAL FINDINGS Results showed that FeADHs from eukaryotes are distributed in thirteen protein subfamilies, eight of them possessing protein sequences distributed in the three domains of life. Interestingly, none of these protein subfamilies possess protein sequences found simultaneously in animals, plants and fungi. Many FeADHs are activated by or contain Fe2+, but many others bind to a variety of metals, or even lack of metal cofactor. Animal FeADHs are found in just one protein subfamily, the hydroxyacid-oxoacid transhydrogenase (HOT) subfamily, which includes protein sequences widely distributed in fungi, but not in plants), and in several taxa from lower eukaryotes, bacteria and archaea. Fungi FeADHs are found mainly in two subfamilies: HOT and maleylacetate reductase (MAR), but some can be found also in other three different protein subfamilies. Plant FeADHs are found only in chlorophyta but not in higher plants, and are distributed in three different protein subfamilies. CONCLUSIONS/SIGNIFICANCE FeADHs are a diverse and ancient protein family that shares a common 3D scaffold with a patchy distribution in eukaryotes. The majority of sequenced FeADHs from eukaryotes are distributed in just two subfamilies, HOT and MAR (found mainly in animals and fungi). These two subfamilies comprise almost 85% of all sequenced FeADHs in eukaryotes.
Collapse
Affiliation(s)
- Carlos Gaona-López
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM). Cd. Universitaria, Ciudad de México, México
| | - Adriana Julián-Sánchez
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM). Cd. Universitaria, Ciudad de México, México
| | - Héctor Riveros-Rosas
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM). Cd. Universitaria, Ciudad de México, México
- * E-mail:
| |
Collapse
|
19
|
Extance J, Danson MJ, Crennell SJ. Structure of an acetylating aldehyde dehydrogenase from the thermophilic ethanologen Geobacillus thermoglucosidasius. Protein Sci 2016; 25:2045-2053. [PMID: 27571338 DOI: 10.1002/pro.3027] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 08/26/2016] [Accepted: 08/26/2016] [Indexed: 11/07/2022]
Abstract
Acetylating aldehyde dehydrogenases (AcAldDH) catalyse the acetylation of Coenzyme-A (CoA), or in reverse generate acetaldehyde from Acetyl-CoA using NADH as a co-factor. This article reports the expression, purification, enzyme assay, and X-ray crystal structures of an AcAldDH from Geobacillus thermoglucosidasius (GtAcAldDH) to 2.1Å and in complex with CoA and NAD+ to 4.0Å. In the structure, the AcAldDH forms a close-knit dimer, similar to that seen in other Alcohol Dehydrogenase (ADH) structures. In GtAcAldDH, these dimers associate via their N-termini to form weakly interacting tetramers. This mode of tetrameric association is also seen in an unpublished AcAldDH deposited in the PDB, but is in contrast to all other ADH structures, (including the one other published AcAldDH found in a bacterial microcompartment), in which the dimers bury a large surface area including the C-termini. This novel mode of association sequesters the active sites and potentially reactive acyl-enzyme intermediates in the center of the tetramer. In other respects, the structure is very similar to the other AcAldDH, binding the cofactors in a corresponding fashion. This similarity enabled the identification of a shortened substrate cavity in G. thermoglucosidasius AcAldDH, explaining the limitations on the length of substrate accepted by the enzyme.
Collapse
Affiliation(s)
- Jonathan Extance
- Centre for Extremophile Research, Department of Biology and Biochemistry, University of Bath, Bath, BA2 7AY, England
| | - Michael J Danson
- Centre for Extremophile Research, Department of Biology and Biochemistry, University of Bath, Bath, BA2 7AY, England
| | - Susan J Crennell
- Centre for Extremophile Research, Department of Biology and Biochemistry, University of Bath, Bath, BA2 7AY, England.
| |
Collapse
|
20
|
Bertsch J, Siemund AL, Kremp F, Müller V. A novel route for ethanol oxidation in the acetogenic bacterium Acetobacterium woodii: the acetaldehyde/ethanol dehydrogenase pathway. Environ Microbiol 2015; 18:2913-22. [PMID: 26472176 DOI: 10.1111/1462-2920.13082] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ethanol is a common substrate for anaerobic microorganisms despite its high redox potential (E0' etha- nol/acetaldehyde = -190mV), which does not allow for NAD(+) reduction. How this thermodynamic barrier is overcome is largely unknown. The acetogenic bacterium Acetobacterium woodii can also grow on ethanol. The genome harbours 11 genes encoding putative alcohol dehydrogenases, but only one, adhE, was upregulated during growth on ethanol. The bifunctional acetaldehyde/ethanol dehydrogenase (AdhE) was purified from ethanol-grown cells. It catalysed the NAD(+) - and CoA-dependent oxidation of ethanol via acetaldehyde to acetyl-CoA. The enzyme was regulated by free coenzyme A: in the absence of coenzyme A, the Km value for ethanol was shifted from 3.4 to 40 mM. The alcohol dehydrogenase domain could also oxidize 1-propanol and 1-butanol; however, the aldehyde dehydrogenase domain was highly specific for acetaldehyde as substrate. Apparently, the bifunctional AdhE allows for NAD(+) reduction by lowering the concentration of acetaldehyde, which makes the first oxidation reaction thermodynamically feasible.
Collapse
Affiliation(s)
- Johannes Bertsch
- Department of Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Max-von-Laue Str. 9, D-60438, Frankfurt, Germany
| | - Anna Lena Siemund
- Department of Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Max-von-Laue Str. 9, D-60438, Frankfurt, Germany
| | - Florian Kremp
- Department of Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Max-von-Laue Str. 9, D-60438, Frankfurt, Germany
| | - Volker Müller
- Department of Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Max-von-Laue Str. 9, D-60438, Frankfurt, Germany.
| |
Collapse
|
21
|
Alcohol Selectivity in a Synthetic Thermophilic n-Butanol Pathway Is Driven by Biocatalytic and Thermostability Characteristics of Constituent Enzymes. Appl Environ Microbiol 2015; 81:7187-200. [PMID: 26253677 DOI: 10.1128/aem.02028-15] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 07/29/2015] [Indexed: 02/06/2023] Open
Abstract
n-Butanol is generated as a natural product of metabolism by several microorganisms, but almost all grow at mesophilic temperatures. A synthetic pathway for n-butanol production from acetyl coenzyme A (acetyl-CoA) that functioned at 70°C was assembled in vitro from enzymes recruited from thermophilic bacteria to inform efforts for engineering butanol production into thermophilic hosts. Recombinant versions of eight thermophilic enzymes (β-ketothiolase [Thl], 3-hydroxybutyryl-CoA dehydrogenase [Hbd], and 3-hydroxybutyryl-CoA dehydratase [Crt] from Caldanaerobacter subterraneus subsp. tengcongensis; trans-2-enoyl-CoA reductase [Ter] from Spirochaeta thermophila; bifunctional acetaldehyde dehydrogenase/alcohol dehydrogenase [AdhE] from Clostridium thermocellum; and AdhE, aldehyde dehydrogenase [Bad], and butanol dehydrogenase [Bdh] from Thermoanaerobacter sp. strain X514) were utilized to examine three possible pathways for n-butanol. These pathways differed in the two steps required to convert butyryl-CoA to n-butanol: Thl-Hbd-Crt-Ter-AdhE (C. thermocellum), Thl-Hbd-Crt-Ter-AdhE (Thermoanaerobacter X514), and Thl-Hbd-Crt-Ter-Bad-Bdh. n-Butanol was produced at 70°C, but with different amounts of ethanol as a coproduct, because of the broad substrate specificities of AdhE, Bad, and Bdh. A reaction kinetics model, validated via comparison to in vitro experiments, was used to determine relative enzyme ratios needed to maximize n-butanol production. By using large relative amounts of Thl and Hbd and small amounts of Bad and Bdh, >70% conversion to n-butanol was observed in vitro, but with a 60% decrease in the predicted pathway flux. With more-selective hypothetical versions of Bad and Bdh, >70% conversion to n-butanol is predicted, with a 19% increase in pathway flux. Thus, more-selective thermophilic versions of Bad, Bdh, and AdhE are needed to fully exploit biocatalytic n-butanol production at elevated temperatures.
Collapse
|
22
|
Biochemical characterization of a bifunctional acetaldehyde-alcohol dehydrogenase purified from a facultative anaerobic bacterium Citrobacter sp. S-77. J Biosci Bioeng 2015. [PMID: 26216639 DOI: 10.1016/j.jbiosc.2015.06.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Acetaldehyde-alcohol dehydrogenase (ADHE) is a bifunctional enzyme consisting of two domains of an N-terminal acetaldehyde dehydrogenase (ALDH) and a C-terminal alcohol dehydrogenase (ADH). The enzyme is known to be important in the cellular alcohol metabolism. However, the role of coenzyme A-acylating ADHE responsible for ethanol production from acetyl-CoA remains uncertain. Here, we present the purification and biochemical characterization of an ADHE from Citrobacter sp. S-77 (ADHE(S77)). Interestingly, the ADHE(S77) was unable to be solubilized from membrane with detergents either 1% Triton X-100 or 1% Sulfobetaine 3-12. However, the enzyme was easily dissociated from membrane by high-salt buffers containing either 1.0 M NaCl or (NH(4))(2)SO(4) without detergents. The molecular weight of a native protein was estimated as approximately 400 kDa, consisting of four identical subunits of 96.3 kDa. Based on the specific activity and kinetic analysis, the ADHES77 tended to have catalytic reaction towards acetaldehyde elimination rather than acetaldehyde formation. Our experimental observation suggests that the ADHES77 may play a pivotal role in modulating intracellular acetaldehyde concentration.
Collapse
|
23
|
Cofactor Specificity of the Bifunctional Alcohol and Aldehyde Dehydrogenase (AdhE) in Wild-Type and Mutant Clostridium thermocellum and Thermoanaerobacterium saccharolyticum. J Bacteriol 2015; 197:2610-9. [PMID: 26013492 DOI: 10.1128/jb.00232-15] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 05/21/2015] [Indexed: 02/07/2023] Open
Abstract
UNLABELLED Clostridium thermocellum and Thermoanaerobacterium saccharolyticum are thermophilic bacteria that have been engineered to produce ethanol from the cellulose and hemicellulose fractions of biomass, respectively. Although engineered strains of T. saccharolyticum produce ethanol with a yield of 90% of the theoretical maximum, engineered strains of C. thermocellum produce ethanol at lower yields (∼50% of the theoretical maximum). In the course of engineering these strains, a number of mutations have been discovered in their adhE genes, which encode both alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) enzymes. To understand the effects of these mutations, the adhE genes from six strains of C. thermocellum and T. saccharolyticum were cloned and expressed in Escherichia coli, the enzymes produced were purified by affinity chromatography, and enzyme activity was measured. In wild-type strains of both organisms, NADH was the preferred cofactor for both ALDH and ADH activities. In high-ethanol-producing (ethanologen) strains of T. saccharolyticum, both ALDH and ADH activities showed increased NADPH-linked activity. Interestingly, the AdhE protein of the ethanologenic strain of C. thermocellum has acquired high NADPH-linked ADH activity while maintaining NADH-linked ALDH and ADH activities at wild-type levels. When single amino acid mutations in AdhE that caused increased NADPH-linked ADH activity were introduced into C. thermocellum and T. saccharolyticum, ethanol production increased in both organisms. Structural analysis of the wild-type and mutant AdhE proteins was performed to provide explanations for the cofactor specificity change on a molecular level. IMPORTANCE This work describes the characterization of the AdhE enzyme from different strains of C. thermocellum and T. saccharolyticum. C. thermocellum and T. saccharolyticum are thermophilic anaerobes that have been engineered to make high yields of ethanol and can solubilize components of plant biomass and ferment the sugars to ethanol. In the course of engineering these strains, several mutations arose in the bifunctional ADH/ALDH protein AdhE, changing both enzyme activity and cofactor specificity. We show that changing AdhE cofactor specificity from mostly NADH linked to mostly NADPH linked resulted in higher ethanol production by C. thermocellum and T. saccharolyticum.
Collapse
|
24
|
Laurenceau R, Krasteva PV, Diallo A, Ouarti S, Duchateau M, Malosse C, Chamot-Rooke J, Fronzes R. Conserved Streptococcus pneumoniae spirosomes suggest a single type of transformation pilus in competence. PLoS Pathog 2015; 11:e1004835. [PMID: 25876066 PMCID: PMC4398557 DOI: 10.1371/journal.ppat.1004835] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 03/26/2015] [Indexed: 11/18/2022] Open
Abstract
The success of S. pneumoniae as a major human pathogen is largely due to its remarkable genomic plasticity, allowing efficient escape from antimicrobials action and host immune response. Natural transformation, or the active uptake and chromosomal integration of exogenous DNA during the transitory differentiated state competence, is the main mechanism for horizontal gene transfer and genomic makeover in pneumococci. Although transforming DNA has been proposed to be captured by Type 4 pili (T4P) in Gram-negative bacteria, and a competence-inducible comG operon encoding proteins homologous to T4P-biogenesis components is present in transformable Gram-positive bacteria, a prevailing hypothesis has been that S. pneumoniae assembles only short pseudopili to destabilize the cell wall for DNA entry. We recently identified a micrometer-sized T4P-like pilus on competent pneumococci, which likely serves as initial DNA receptor. A subsequent study, however, visualized a different structure--short, 'plaited' polymers--released in the medium of competent S. pneumoniae. Biochemical observation of concurrent pilin secretion led the authors to propose that the 'plaited' structures correspond to transformation pili acting as peptidoglycan drills that leave DNA entry pores upon secretion. Here we show that the 'plaited' filaments are not related to natural transformation as they are released by non-competent pneumococci, as well as by cells with disrupted pilus biogenesis components. Combining electron microscopy visualization with structural, biochemical and proteomic analyses, we further identify the 'plaited' polymers as spirosomes: macromolecular assemblies of the fermentative acetaldehyde-alcohol dehydrogenase enzyme AdhE that is well conserved in a broad range of Gram-positive and Gram-negative bacteria.
Collapse
Affiliation(s)
- Raphaël Laurenceau
- Unité G5 Biologie Structurale de la Sécrétion Bactérienne, Institut Pasteur, Paris, France
- UMR 3528, CNRS, Institut Pasteur, Paris, France
| | - Petya V. Krasteva
- Unité G5 Biologie Structurale de la Sécrétion Bactérienne, Institut Pasteur, Paris, France
- UMR 3528, CNRS, Institut Pasteur, Paris, France
- * E-mail: (PVK); (RF)
| | - Amy Diallo
- Unité G5 Biologie Structurale de la Sécrétion Bactérienne, Institut Pasteur, Paris, France
- UMR 3528, CNRS, Institut Pasteur, Paris, France
| | - Sahra Ouarti
- Unité G5 Biologie Structurale de la Sécrétion Bactérienne, Institut Pasteur, Paris, France
- UMR 3528, CNRS, Institut Pasteur, Paris, France
| | - Magalie Duchateau
- UMR 3528, CNRS, Institut Pasteur, Paris, France
- Spectrométrie de Masse Structurale et Protéomique, Institut Pasteur, Paris, France
- Plate-Forme de Protéomique, Institut Pasteur, Paris, France
| | - Christian Malosse
- UMR 3528, CNRS, Institut Pasteur, Paris, France
- Spectrométrie de Masse Structurale et Protéomique, Institut Pasteur, Paris, France
- Plate-Forme de Protéomique, Institut Pasteur, Paris, France
| | - Julia Chamot-Rooke
- UMR 3528, CNRS, Institut Pasteur, Paris, France
- Spectrométrie de Masse Structurale et Protéomique, Institut Pasteur, Paris, France
- Plate-Forme de Protéomique, Institut Pasteur, Paris, France
| | - Rémi Fronzes
- Unité G5 Biologie Structurale de la Sécrétion Bactérienne, Institut Pasteur, Paris, France
- UMR 3528, CNRS, Institut Pasteur, Paris, France
- * E-mail: (PVK); (RF)
| |
Collapse
|
25
|
Olson DG, Sparling R, Lynd LR. Ethanol production by engineered thermophiles. Curr Opin Biotechnol 2015; 33:130-41. [PMID: 25745810 DOI: 10.1016/j.copbio.2015.02.006] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Revised: 02/11/2015] [Accepted: 02/13/2015] [Indexed: 12/17/2022]
Abstract
We compare a number of different strategies that have been pursued to engineer thermophilic microorganisms for increased ethanol production. Ethanol production from pyruvate can proceed via one of four pathways, which are named by the key pyruvate dissimilating enzyme: pyruvate decarboxylase (PDC), pyruvate dehydrogenase (PDH), pyruvate formate lyase (PFL), and pyruvate ferredoxin oxidoreductase (PFOR). For each of these pathways except PFL, we see examples where ethanol production has been engineered with a yield of >90% of the theoretical maximum. In each of these cases, this engineering was achieved mainly by modulating expression of native genes. We have not found an example where a thermophilic ethanol production pathway has been transferred to a non-ethanol-producing organism to produce ethanol at high yield. A key reason for the lack of transferability of ethanol production pathways is the current lack of understanding of the enzymes involved.
Collapse
Affiliation(s)
- Daniel G Olson
- Thayer School of Engineering at Dartmouth College, Hanover, NH 03755, United States; BioEnergy Science Center, Oak Ridge, TN 37830, United States
| | - Richard Sparling
- Department of Microbiology, University of Manitoba, Winnipeg, MB, Canada R3T 5V6
| | - Lee R Lynd
- Thayer School of Engineering at Dartmouth College, Hanover, NH 03755, United States; BioEnergy Science Center, Oak Ridge, TN 37830, United States.
| |
Collapse
|
26
|
Bertsch J, Müller V. Bioenergetic constraints for conversion of syngas to biofuels in acetogenic bacteria. BIOTECHNOLOGY FOR BIOFUELS 2015; 8:210. [PMID: 26692897 PMCID: PMC4676187 DOI: 10.1186/s13068-015-0393-x] [Citation(s) in RCA: 117] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 11/17/2015] [Indexed: 05/05/2023]
Abstract
Synthesis gas (syngas) is a gas mixture consisting mainly of H2, CO, and CO2 and can be derived from different sources, including renewable materials like lignocellulose. The fermentation of syngas to certain biofuels, using acetogenic bacteria, has attracted more and more interest over the last years. However, this technology is limited by two things: (1) the lack of complete knowledge of the energy metabolism of acetogenic bacteria, and (2) the lack of sophisticated genetic tools for the modification of acetogens. In this review, we discuss the bioenergetic constraints for the conversion of syngas to different biofuels. We will mainly focus on Acetobacterium woodii, which is the best understood acetogen in terms of energy conservation. Syngas fermentation with Clostridium autoethanogenum will also be discussed, since this organism is well suited to convert syngas to certain products and already used in large-scale industrial processes.
Collapse
Affiliation(s)
- Johannes Bertsch
- Department of Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Volker Müller
- Department of Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| |
Collapse
|
27
|
A hybrid synthetic pathway for butanol production by a hyperthermophilic microbe. Metab Eng 2014; 27:101-106. [PMID: 25461832 DOI: 10.1016/j.ymben.2014.11.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Revised: 10/04/2014] [Accepted: 11/12/2014] [Indexed: 01/19/2023]
Abstract
Biologically produced alcohols are of great current interest for renewable solvents and liquid transportation fuels. While bioethanol is now produced on a massive scale, butanol has superior fuel characteristics and an additional value as a solvent and chemical feedstock. Butanol production has been demonstrated at ambient temperatures in metabolically-engineered mesophilic organisms, but the ability to engineer a microbe for in vivo high-temperature production of commodity chemicals has several distinct advantages. These include reduced contamination risk, facilitated removal of volatile products, and a wide temperature range to modulate and balance both the engineered pathway and the host׳s metabolism. We describe a synthetic metabolic pathway assembled from genes obtained from three different sources for conversion of acetyl-CoA to 1-butanol, and 1-butanol generation from glucose was demonstrated near 70°C in a microorganism that grows optimally near 100°C. The module could also be used in thermophiles capable of degrading plant biomass.
Collapse
|
28
|
Hydrogen formation and its regulation in Ruminococcus albus: involvement of an electron-bifurcating [FeFe]-hydrogenase, of a non-electron-bifurcating [FeFe]-hydrogenase, and of a putative hydrogen-sensing [FeFe]-hydrogenase. J Bacteriol 2014; 196:3840-52. [PMID: 25157086 DOI: 10.1128/jb.02070-14] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Ruminococcus albus 7 has played a key role in the development of the concept of interspecies hydrogen transfer. The rumen bacterium ferments glucose to 1.3 acetate, 0.7 ethanol, 2 CO2, and 2.6 H2 when growing in batch culture and to 2 acetate, 2 CO2, and 4 H2 when growing in continuous culture in syntrophic association with H2-consuming microorganisms that keep the H2 partial pressure low. The organism uses NAD(+) and ferredoxin for glucose oxidation to acetyl coenzyme A (acetyl-CoA) and CO2, NADH for the reduction of acetyl-CoA to ethanol, and NADH and reduced ferredoxin for the reduction of protons to H2. Of all the enzymes involved, only the enzyme catalyzing the formation of H2 from NADH remained unknown. Here, we report that R. albus 7 grown in batch culture on glucose contained, besides a ferredoxin-dependent [FeFe]-hydrogenase (HydA2), a ferredoxin- and NAD-dependent electron-bifurcating [FeFe]-hydrogenase (HydABC) that couples the endergonic formation of H2 from NADH to the exergonic formation of H2 from reduced ferredoxin. Interestingly, hydA2 is adjacent to the hydS gene, which is predicted to encode an [FeFe]-hydrogenase with a C-terminal PAS domain. We showed that hydS and hydA2 are part of a larger transcriptional unit also harboring putative genes for a bifunctional acetaldehyde/ethanol dehydrogenase (Aad), serine/threonine protein kinase, serine/threonine protein phosphatase, and a redox-sensing transcriptional repressor. Since HydA2 and Aad are required only when R. albus grows at high H2 partial pressures, HydS could be a H2-sensing [FeFe]-hydrogenase involved in the regulation of their biosynthesis.
Collapse
|
29
|
Blikstad C, Dahlström KM, Salminen TA, Widersten M. Substrate scope and selectivity in offspring to an enzyme subjected to directed evolution. FEBS J 2014; 281:2387-98. [PMID: 24673815 DOI: 10.1111/febs.12791] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 03/12/2014] [Accepted: 03/24/2014] [Indexed: 11/28/2022]
Abstract
We have analyzed the effects of mutations inserted during directed evolution of a specialized enzyme, Escherichia coli S-1,2-propanediol oxidoreductase (FucO). The kinetic properties of evolved variants have been determined and the observed differences have been rationalized by modeling the tertiary structures of isolated variants and the wild-type enzyme. The native substrate, S-1,2-propanediol, as well as phenylacetaldehyde and 2S-3-phenylpropane-1,2-diol, which are new substrates accepted by isolated variants, were docked into the active sites. The study provides a comprehensive picture of how acquired catalytic properties have arisen via an intermediate generalist enzyme, which had acquired a single mutation (L259V) in the active site. Further mutagenesis of this generalist resulted in a new specialist catalyst. We have also been able to relate the native enzyme activities to the evolved ones and linked the differences to individual amino acid residues important for activity and selectivity. F254 plays a dual role in the enzyme function. First, mutation of F254 into an isoleucine weakens the interactions with the coenzyme thereby increasing its dissociation rate from the active site and resulting in a four-fold increase in turnover number with S-1,2-propanediol. Second, F254 is directly involved in binding of aryl-substituted substrates via π-π interactions. On the other hand, N151 is critical in determining the substrate scope since the side chain amide group stabilizes binding of 1,2-substituted diols and is apparently necessary for enzymatic activity with these substrates. Moreover, the side chain of N151 introduces steric hindrance, which prevents high activity with phenylacetaldehyde. Additionally, the hydroxyl group of T149 is required to maintain the catalytically important hydrogen bonding network.
Collapse
|