1
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Zhan T, Jacoby C, Jede M, Knapp B, Ferlaino S, Günter A, Drepper F, Müller M, Weber S, Boll M. Bacterial stigmasterol degradation involving radical flavin delta-24 desaturase and molybdenum-dependent C26 hydroxylase. J Biol Chem 2024; 300:107243. [PMID: 38556086 PMCID: PMC11061730 DOI: 10.1016/j.jbc.2024.107243] [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: 02/01/2024] [Revised: 03/20/2024] [Accepted: 03/24/2024] [Indexed: 04/02/2024] Open
Abstract
Sterols are ubiquitous membrane constituents that persist to a large extent in the environment due to their water insolubility and chemical inertness. Recently, an oxygenase-independent sterol degradation pathway was discovered in a cholesterol-grown denitrifying bacterium Sterolibacterium (S.) denitrificans. It achieves hydroxylation of the unactivated primary C26 of the isoprenoid side chain to an allylic alcohol via a phosphorylated intermediate in a four-step ATP-dependent enzyme cascade. However, this pathway is incompatible with the degradation of widely distributed steroids containing a double bond at C22 in the isoprenoid side chain such as the plant sterol stigmasterol. Here, we have enriched a prototypical delta-24 desaturase from S. denitrificans, which catalyzes the electron acceptor-dependent oxidation of the intermediate stigmast-1,4-diene-3-one to a conjugated (22,24)-diene. We suggest an α4β4 architecture of the 440 kDa enzyme, with each subunit covalently binding an flavin mononucleotide cofactor to a histidyl residue. As isolated, both flavins are present as red semiquinone radicals, which can be reduced by stigmast-1,4-diene-3-one but cannot be oxidized even with strong oxidizing agents. We propose a mechanism involving an allylic radical intermediate in which two flavin semiquinones each abstract one hydrogen atom from the substrate. The conjugated delta-22,24 moiety formed allows for the subsequent hydroxylation of the terminal C26 with water by a heterologously produced molybdenum-dependent steroid C26 dehydrogenase 2. In conclusion, the pathway elucidated for delta-22 steroids achieves oxygen-independent hydroxylation of the isoprenoid side chain by bypassing the ATP-dependent formation of a phosphorylated intermediate.
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Affiliation(s)
- Tingyi Zhan
- Faculty of Biology, Department of Microbiology, University of Freiburg, Freiburg, Germany
| | - Christian Jacoby
- Faculty of Biology, Department of Microbiology, University of Freiburg, Freiburg, Germany
| | - Martin Jede
- Faculty of Biology, Department of Microbiology, University of Freiburg, Freiburg, Germany
| | - Bettina Knapp
- Faculty of Biology, Department of Biochemistry and Functional Proteomics, University of Freiburg, Freiburg, Germany
| | - Sascha Ferlaino
- Institute of Pharmaceutical Sciences, University of Freiburg, Freiburg, Germany
| | - Andreas Günter
- Institute of Physical Chemistry, University of Freiburg, Freiburg, Germany
| | - Friedel Drepper
- Faculty of Biology, Department of Biochemistry and Functional Proteomics, University of Freiburg, Freiburg, Germany
| | - Michael Müller
- Institute of Pharmaceutical Sciences, University of Freiburg, Freiburg, Germany
| | - Stefan Weber
- Institute of Physical Chemistry, University of Freiburg, Freiburg, Germany
| | - Matthias Boll
- Faculty of Biology, Department of Microbiology, University of Freiburg, Freiburg, Germany.
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2
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Kosian D, Willistein M, Weßbecher R, Eggers C, May O, Boll M. Highly selective whole-cell 25-hydroxyvitamin D 3 synthesis using molybdenum-dependent C25-steroid dehydrogenase and cyclodextrin recycling. Microb Cell Fact 2024; 23:30. [PMID: 38245746 PMCID: PMC10799449 DOI: 10.1186/s12934-024-02303-6] [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: 11/14/2023] [Accepted: 01/12/2024] [Indexed: 01/22/2024] Open
Abstract
BACKGROUND The global prevalence of vitamin D (VitD) deficiency associated with numerous acute and chronic diseases has led to strategies to improve the VitD status through dietary intake of VitD-fortified foods and VitD supplementation. In this context, the circulating form of VitD3 (cholecalciferol) in the human body, 25-hydroxy-VitD3 (calcifediol, 25OHVitD3), has a much higher efficacy in improving the VitD status, which has motivated researchers to develop methods for its effective and sustainable synthesis. Conventional monooxygenase-/peroxygenase-based biocatalytic platforms for the conversion of VitD3 to value-added 25OHVitD3 are generally limited by a low selectivity and yield, costly reliance on cyclodextrins and electron donor systems, or by the use of toxic co-substrates. RESULTS In this study, we used a whole-cell approach for biocatalytic 25OHVitD3 synthesis, in which a molybdenum-dependent steroid C25 dehydrogenase was produced in the denitrifying bacterium Thauera aromatica under semi-aerobic conditions, where the activity of the enzyme remained stable. This enzyme uses water as a highly selective VitD3 hydroxylating agent and is independent of an electron donor system. High density suspensions of resting cells producing steroid C25 dehydrogenase catalysed the conversion of VitD3 to 25OHVitD3 using either O2 via the endogenous respiratory chain or externally added ferricyanide as low cost electron acceptor. The maximum 25OHVitD3 titer achieved was 1.85 g L-1 within 50 h with a yield of 99%, which is 2.2 times higher than the highest reported value obtained with previous biocatalytic systems. In addition, we developed a simple method for the recycling of the costly VitD3 solubiliser cyclodextrin, which could be reused for 10 reaction cycles without a significant loss of quality or quantity. CONCLUSIONS The established steroid C25 dehydrogenase-based whole-cell system for the value-adding conversion of VitD3 to 25OHVitD3 offers a number of advantages in comparison to conventional oxygenase-/peroxygenase-based systems including its high selectivity, independence from an electron donor system, and the higher product titer and yield. Together with the established cyclodextrin recycling procedure, the established system provides an attractive platform for large-scale 25OHVitD3 synthesis.
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Affiliation(s)
- Dennis Kosian
- Faculty of Biology - Microbiology, University of Freiburg, 79104, Freiburg, Germany
| | - Max Willistein
- Faculty of Biology - Microbiology, University of Freiburg, 79104, Freiburg, Germany
| | - Ralf Weßbecher
- Faculty of Biology - Microbiology, University of Freiburg, 79104, Freiburg, Germany
| | - Constantin Eggers
- Faculty of Biology - Microbiology, University of Freiburg, 79104, Freiburg, Germany
| | - Oliver May
- DSM Nutritional Products, Koninklijke DSM N.V., Kaiseraugst, 4303, Switzerland
| | - Matthias Boll
- Faculty of Biology - Microbiology, University of Freiburg, 79104, Freiburg, Germany.
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3
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Magalon A. History of Maturation of Prokaryotic Molybdoenzymes-A Personal View. Molecules 2023; 28:7195. [PMID: 37894674 PMCID: PMC10609526 DOI: 10.3390/molecules28207195] [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: 09/25/2023] [Revised: 10/11/2023] [Accepted: 10/17/2023] [Indexed: 10/29/2023] Open
Abstract
In prokaryotes, the role of Mo/W enzymes in physiology and bioenergetics is widely recognized. It is worth noting that the most diverse family of Mo/W enzymes is exclusive to prokaryotes, with the probable existence of several of them from the earliest forms of life on Earth. The structural organization of these enzymes, which often include additional redox centers, is as diverse as ever, as is their cellular localization. The most notable observation is the involvement of dedicated chaperones assisting with the assembly and acquisition of the metal centers, including Mo/W-bisPGD, one of the largest organic cofactors in nature. This review seeks to provide a new understanding and a unified model of Mo/W enzyme maturation.
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Affiliation(s)
- Axel Magalon
- Aix Marseille Université, CNRS, Laboratoire de Chimie Bactérienne (UMR7283), IMM, IM2B, 13402 Marseille, France
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4
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Wang Z, Zeng Y, Jia H, Yang N, Liu M, Jiang M, Zheng Y. Bioconversion of vitamin D 3 to bioactive calcifediol and calcitriol as high-value compounds. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2022; 15:109. [PMID: 36229827 PMCID: PMC9563128 DOI: 10.1186/s13068-022-02209-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Accepted: 10/04/2022] [Indexed: 11/07/2022]
Abstract
Biological catalysis is an important approach for the production of high-value-added compounds, especially for products with complex structures. Limited by the complex steps of chemical synthesis and low yields, the bioconversion of vitamin D3 (VD3) to calcifediol and calcitriol, which are natural steroid products with high added value and significantly higher biological activity compared to VD3, is probably the most promising strategy for calcifediol and calcitriol production, and can be used as an alternative method for chemical synthesis. The conversion efficiency of VD3 to calcifediol and calcitriol has continued to rise in the past few decades with the help of several different VD3 hydroxylases, mostly cytochrome P450s (CYPs), and newly isolated strains. The production of calcifediol and calcitriol can be systematically increased in different ways. Specific CYPs and steroid C25 dehydrogenase (S25DH), as VD3 hydroxylases, are capable of converting VD3 to calcifediol and calcitriol. Some isolated actinomycetes have also been exploited for fermentative production of calcifediol and calcitriol, although the VD3 hydroxylases of these strains have not been elucidated. With the rapid development of synthetic biology and enzyme engineering, quite a lot of advances in bioproduction of calcifediol and calcitriol has been achieved in recent years. Therefore, here we review the successful strategies of promoting VD3 hydroxylation and provide some perspective on how to further improve the bioconversion of VD3 to calcifediol and calcitriol.
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Affiliation(s)
- Zheyi Wang
- grid.9227.e0000000119573309State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No.1 Beichen West Road, Chaoyang District, Beijing, 100101 China ,grid.410726.60000 0004 1797 8419University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing, 100049 China
| | - Yan Zeng
- grid.9227.e0000000119573309State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No.1 Beichen West Road, Chaoyang District, Beijing, 100101 China
| | - Hongmin Jia
- China Animal Husbandry Industry Co. Ltd, Beijing, 100095 China
| | - Niping Yang
- grid.256885.40000 0004 1791 4722School of Life Sciences, Hebei University, No. 180 Wusi Dong Road, Baoding, 071002 China
| | - Mengshuang Liu
- grid.9227.e0000000119573309State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No.1 Beichen West Road, Chaoyang District, Beijing, 100101 China ,grid.410726.60000 0004 1797 8419University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing, 100049 China
| | - Mingyue Jiang
- grid.9227.e0000000119573309State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No.1 Beichen West Road, Chaoyang District, Beijing, 100101 China ,grid.410726.60000 0004 1797 8419University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing, 100049 China
| | - Yanning Zheng
- grid.9227.e0000000119573309State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No.1 Beichen West Road, Chaoyang District, Beijing, 100101 China
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5
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Jacoby C, Ebenau-Jehle C, Saum K, Jehmlich N, von Bergen M, Brüls T, Boll M. Genes and enzymes involved in the biodegradation of the quaternary carbon compound pivalate in the denitrifying Thauera humireducens strain PIV-1. Environ Microbiol 2022; 24:3181-3194. [PMID: 35437936 DOI: 10.1111/1462-2920.16021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 04/14/2022] [Accepted: 04/17/2022] [Indexed: 11/28/2022]
Abstract
Quaternary carbon containing compounds exist in natural and fossil oil derived products and are used in chemical and pharmaceutical applications up to industrial scale. Due to the inaccessibility of the quaternary carbon atom for a direct oxidative or reductive attack, they are considered as persistent in the environment. Here, we investigated the unknown degradation of the quaternary carbon-containing model compound pivalate (2,2-dimethyl-propionate) in the denitrifying bacterium Thauera humireducens strain PIV-1 (formerly T. pivalivorans). We provide multiple evidence for a pathway comprising the activation to pivalyl-CoA and the carbon skeleton rearrangement to isovaleryl-CoA. Subsequent reactions proceed similar to the catabolic leucine degradation pathway such as the carboxylation to 3-methylglutaconyl-CoA and the cleavage of 3-methyl-3-hydroxyglutaryl-CoA to acetyl-CoA and acetoacetate. The completed genome of Thauera humireducens strain PIV-1 together with proteomic data was used to identify pivalate-upregulated gene clusters including genes putatively encoding pivalate CoA ligase and adenosylcobalamin-dependent pivalyl-CoA mutase. A pivalate-induced gene encoding a putative carboxylic acid CoA ligase was heterologously expressed, and its highly enriched product exhibited pivalate CoA ligase activity. The results provide first experimental insights into the biodegradation pathway of a quaternary carbon-containing model compound that serves as a blueprint for the degradation of related quaternary carbon-containing compounds. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Christian Jacoby
- Faculty of Biology - Microbiology, University of Freiburg, 79104, Freiburg, Germany
| | - Christa Ebenau-Jehle
- Faculty of Biology - Microbiology, University of Freiburg, 79104, Freiburg, Germany
| | - Katharina Saum
- Faculty of Biology - Microbiology, University of Freiburg, 79104, Freiburg, Germany
| | - Nico Jehmlich
- Department of Analytical Chemistry, Helmholtz Centre for Environmental Research - UFZ, 04318, Leipzig, Germany.,Department of Molecular Systems Biology, Helmholtz,Centre for Environmental Research -.UFZ, 04318, Leipzig, Germany
| | - Martin von Bergen
- Department of Analytical Chemistry, Helmholtz Centre for Environmental Research - UFZ, 04318, Leipzig, Germany.,Department of Molecular Systems Biology, Helmholtz,Centre for Environmental Research -.UFZ, 04318, Leipzig, Germany.,Faculty of Life Sciences, Institute of Biochemistry, University of Leipzig, Brüderstr. 34, 04103, Leipzig, Germany
| | - Thomas Brüls
- Génomique métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, Evry, France
| | - Matthias Boll
- Faculty of Biology - Microbiology, University of Freiburg, 79104, Freiburg, Germany
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6
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Le CC, Bae M, Kiamehr S, Balskus EP. Emerging Chemical Diversity and Potential Applications of Enzymes in the DMSO Reductase Superfamily. Annu Rev Biochem 2022; 91:475-504. [PMID: 35320685 DOI: 10.1146/annurev-biochem-032620-110804] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Molybdenum- and tungsten-dependent proteins catalyze essential processes in living organisms and biogeochemical cycles. Among these enzymes, members of the dimethyl sulfoxide (DMSO) reductase superfamily are considered the most diverse, facilitating a wide range of chemical transformations that can be categorized as oxygen atom installation, removal, and transfer. Importantly, DMSO reductase enzymes provide high efficiency and excellent selectivity while operating under mild conditions without conventional oxidants such as oxygen or peroxides. Despite the potential utility of these enzymes as biocatalysts, such applications have not been fully explored. In addition, the vast majority of DMSO reductase enzymes still remain uncharacterized. In this review, we describe the reactivities, proposed mechanisms, and potential synthetic applications of selected enzymes in the DMSO reductase superfamily. We also highlight emerging opportunities to discover new chemical activity and current challenges in studying and engineering proteins in the DMSO reductase superfamily. Expected final online publication date for the Annual Review of Biochemistry, Volume 91 is June 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Chi Chip Le
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, USA;
| | - Minwoo Bae
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, USA;
| | - Sina Kiamehr
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, USA;
| | - Emily P Balskus
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, USA;
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7
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Hagel C, Blaum B, Friedrich T, Heider J. Characterisation of the redox centers of ethylbenzene dehydrogenase. J Biol Inorg Chem 2021; 27:143-154. [PMID: 34843002 PMCID: PMC8840923 DOI: 10.1007/s00775-021-01917-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 10/29/2021] [Indexed: 01/18/2023]
Abstract
Ethylbenzene dehydrogenase (EbDH), the initial enzyme of anaerobic ethylbenzene degradation from the beta-proteobacterium Aromatoleum aromaticum, is a soluble periplasmic molybdenum enzyme consisting of three subunits. It contains a Mo-bis-molybdopterin guanine dinucleotide (Mo-bis-MGD) cofactor and an 4Fe-4S cluster (FS0) in the α-subunit, three 4Fe-4S clusters (FS1 to FS3) and a 3Fe-4S cluster (FS4) in the β-subunit and a heme b cofactor in the γ-subunit. Ethylbenzene is hydroxylated by a water molecule in an oxygen-independent manner at the Mo-bis-MGD cofactor, which is reduced from the MoVI to the MoIV state in two subsequent one-electron steps. The electrons are then transferred via the Fe-S clusters to the heme b cofactor. In this report, we determine the midpoint redox potentials of the Mo-bis-MGD cofactor and FS1-FS4 by EPR spectroscopy, and that of the heme b cofactor by electrochemically induced redox difference spectroscopy. We obtained relatively high values of > 250 mV both for the MoVI-MoV redox couple and the heme b cofactor, whereas FS2 is only reduced at a very low redox potential, causing magnetic coupling with the neighboring FS1 and FS3. We compare the results with the data on related enzymes and interpret their significance for the function of EbDH.
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Affiliation(s)
- Corina Hagel
- Labor für Mikrobielle Biochemie and Synmikro Zentrum für Synthetische Mikrobiologie, Philipps Universität Marburg, 35043, Marburg, Germany
| | - Bärbel Blaum
- Institut für Biochemie, Albert-Ludwigs Universität, Albertstr. 21, 79104, Freiburg im Breisgau, Germany
| | - Thorsten Friedrich
- Institut für Biochemie, Albert-Ludwigs Universität, Albertstr. 21, 79104, Freiburg im Breisgau, Germany.
| | - Johann Heider
- Labor für Mikrobielle Biochemie and Synmikro Zentrum für Synthetische Mikrobiologie, Philipps Universität Marburg, 35043, Marburg, Germany.
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8
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Jacoby C, Goerke M, Bezold D, Jessen H, Boll M. A fully reversible 25-hydroxy steroid kinase involved in oxygen-independent cholesterol side-chain oxidation. J Biol Chem 2021; 297:101105. [PMID: 34425106 PMCID: PMC8449060 DOI: 10.1016/j.jbc.2021.101105] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 08/18/2021] [Accepted: 08/19/2021] [Indexed: 11/29/2022] Open
Abstract
The degradation of cholesterol and related steroids by microbes follows fundamentally different strategies in aerobic and anaerobic environments. In anaerobic bacteria, the primary C26 of the isoprenoid side chain is hydroxylated without oxygen via a three-step cascade: (i) water-dependent hydroxylation at the tertiary C25, (ii) ATP-dependent dehydration to form a subterminal alkene, and (iii) water-dependent hydroxylation at the primary C26 to form an allylic alcohol. However, the enzymes involved in the ATP-dependent dehydration have remained unknown. Here, we isolated an ATP-dependent 25-hydroxy-steroid kinase (25-HSK) from the anaerobic bacterium Sterolibacterium denitrificans. This highly active enzyme preferentially phosphorylated the tertiary C25 of steroid alcohols, including metabolites of cholesterol and sitosterol degradation or 25-OH-vitamin D3. Kinetic data were in agreement with a sequential mechanism via a ternary complex. Remarkably, 25-HSK readily catalyzed the formation of γ-(18O)2-ATP from ADP and the C25-(18O)2-phosphoester. The observed full reversibility of 25-HSK with an equilibrium constant below one can be rationalized by an unusual high phosphoryl transfer potential of tertiary steroid C25-phosphoesters, which is ≈20 kJ mol−1 higher than that of standard sugar phosphoesters and even slightly greater than the β,γ-phosphoanhydride of ATP. In summary, 25-HSK plays an essential role in anaerobic bacterial degradation of zoo- and phytosterols and shows only little similarity to known phosphotransferases.
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Affiliation(s)
- Christian Jacoby
- Faculty of Biology, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Malina Goerke
- Faculty of Biology, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Dominik Bezold
- Institute of Organic Chemistry, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Henning Jessen
- Institute of Organic Chemistry, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Matthias Boll
- Faculty of Biology, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany.
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9
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Affiliation(s)
- Judith Münch
- Leibniz Institute of Plant Biochemistry, Weinberg 3, 06120, Halle, Saale, Germany
| | - Pascal Püllmann
- Leibniz Institute of Plant Biochemistry, Weinberg 3, 06120, Halle, Saale, Germany
| | - Wuyuan Zhang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West seventh Avenue, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, 32 West seventh Avenue, Tianjin 300308, China
| | - Martin J. Weissenborn
- Leibniz Institute of Plant Biochemistry, Weinberg 3, 06120, Halle, Saale, Germany
- Institute of Chemistry, MartinLuther-University Halle-Wittenberg, Kurt-Mothes-Strasse 2, 06120, Halle, Saale, Germany
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10
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Sousa EH, Carepo MS, Moura JJ. Nitrate-nitrite fate and oxygen sensing in dormant Mycobacterium tuberculosis: A bioinorganic approach highlighting the importance of transition metals. Coord Chem Rev 2020. [DOI: 10.1016/j.ccr.2020.213476] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
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11
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Jacoby C, Ferlaino S, Bezold D, Jessen H, Müller M, Boll M. ATP-dependent hydroxylation of an unactivated primary carbon with water. Nat Commun 2020; 11:3906. [PMID: 32764563 PMCID: PMC7411048 DOI: 10.1038/s41467-020-17675-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 07/09/2020] [Indexed: 11/09/2022] Open
Abstract
Enzymatic hydroxylation of unactivated primary carbons is generally associated with the use of molecular oxygen as co-substrate for monooxygenases. However, in anaerobic cholesterol-degrading bacteria such as Sterolibacterium denitrificans the primary carbon of the isoprenoid side chain is oxidised to a carboxylate in the absence of oxygen. Here, we identify an enzymatic reaction sequence comprising two molybdenum-dependent hydroxylases and one ATP-dependent dehydratase that accomplish the hydroxylation of unactivated primary C26 methyl group of cholesterol with water: (i) hydroxylation of C25 to a tertiary alcohol, (ii) ATP-dependent dehydration to an alkene via a phosphorylated intermediate, (iii) hydroxylation of C26 to an allylic alcohol that is subsequently oxidised to the carboxylate. The three-step enzymatic reaction cascade divides the high activation energy barrier of primary C–H bond cleavage into three biologically feasible steps. This finding expands our knowledge of biological C–H activations beyond canonical oxygenase-dependent reactions. Monooxygenases catalyse the hydroxylation of C-H bonds using oxygen as a co-substrate, which, in turn, is unavailable for anaerobic bacteria. Here, the authors report a three-step reaction cascade involving two hydroxylases and one dehydratase which hydroxylate the C26 methyl group of cholesterol with water as a co-substrate.
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Affiliation(s)
- Christian Jacoby
- Microbiology, Faculty of Biology, Albert-Ludwigs-Universität Freiburg, Schänzlestr. 1, 79104, Freiburg, Germany
| | - Sascha Ferlaino
- Institute of Pharmaceutical Sciences, Albert-Ludwigs-Universität Freiburg, Albertstrasse 25, 79104, Freiburg, Germany
| | - Dominik Bezold
- Institute of Organic Chemistry, Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, 79104, Freiburg, Germany
| | - Henning Jessen
- Institute of Organic Chemistry, Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, 79104, Freiburg, Germany
| | - Michael Müller
- Institute of Pharmaceutical Sciences, Albert-Ludwigs-Universität Freiburg, Albertstrasse 25, 79104, Freiburg, Germany
| | - Matthias Boll
- Microbiology, Faculty of Biology, Albert-Ludwigs-Universität Freiburg, Schänzlestr. 1, 79104, Freiburg, Germany.
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12
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Functional mononuclear molybdenum enzymes: challenges and triumphs in molecular cloning, expression, and isolation. J Biol Inorg Chem 2020; 25:547-569. [PMID: 32279136 DOI: 10.1007/s00775-020-01787-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 03/30/2020] [Indexed: 10/24/2022]
Abstract
Mononuclear molybdenum enzymes catalyze a variety of reactions that are essential in the cycling of nitrogen, carbon, arsenic, and sulfur. For decades, the structure and function of these crucial enzymes have been investigated to develop a fundamental knowledge for this vast family of enzymes and the chemistries they carry out. Therefore, obtaining abundant quantities of active enzyme is necessary for exploring this family's biochemical capability. This mini-review summarizes the methods for overexpressing mononuclear molybdenum enzymes in the context of the challenges encountered in the process. Effective methods for molybdenum cofactor synthesis and incorporation, optimization of expression conditions, improving isolation of active vs. inactive enzyme, incorporation of additional prosthetic groups, and inclusion of redox enzyme maturation protein chaperones are discussed in relation to the current molybdenum enzyme literature. This article summarizes the heterologous and homologous expression studies providing underlying patterns and potential future directions.
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Tang D, Liu W, Huang L, Cheng L, Xu Z. Efficient biotransformation of vitamin D 3 to 25-hydroxyvitamin D 3 by a newly isolated Bacillus cereus strain. Appl Microbiol Biotechnol 2019; 104:765-774. [PMID: 31776608 DOI: 10.1007/s00253-019-10250-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 10/24/2019] [Accepted: 11/05/2019] [Indexed: 02/07/2023]
Abstract
25-hydroxyvitamin D3 has attracted considerable attention due to its great medical value and huge market demand in animal husbandry. Microbial production of 25-hydroxyvitamin D3 has been recognized as an alternative superior to traditional chemical synthesis. In this study, a Gram-positive bacteria zju 4-2 (CCTCC M 2019385) was isolated from the soil using vitamin D3 as the sole carbon source and was identified as Bacillus cereus according to its physiological characteristics and 16S rRNA analysis, which also showed a relatively high capacity for 25-hydroxyvitamin D3 production. Through systematic optimization of different catalytic conditions, the optimal solvent system of vitamin D3, vitamin D3 addition time and concentration, temperature, and pH were shown to be propylene glycol/ethanol (v/v = 9:1), early stationary phase, 2 g/L, 37 °C, and pH 7.2, respectively. With these optimal conditions, 796 mg/L of 25-hydroxyvitamin D3 was achieved after 48 h bioconversion with zju 4-2 at the shake flask level. Finally, up to 830 mg/L 25-hydroxyvitamin D3 with a yield of 41.5% was obtained in a 5 L fermentation tank. Our developed biotransformation process with this newly isolated strain provides a platform to produce 25-hydroxyvitamin D3 efficiently at industrialization scale.
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Affiliation(s)
- Dandan Tang
- State Key Laboratory of Clean Energy Utilization, College of Energy Engineering, Zhejiang University, Hangzhou, 310027, China.,Key Laboratory of Biomass Chemical Engineering (Education Ministry), College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Wei Liu
- Key Laboratory of Biomass Chemical Engineering (Education Ministry), College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Lei Huang
- Key Laboratory of Biomass Chemical Engineering (Education Ministry), College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Leming Cheng
- State Key Laboratory of Clean Energy Utilization, College of Energy Engineering, Zhejiang University, Hangzhou, 310027, China.
| | - Zhinan Xu
- Key Laboratory of Biomass Chemical Engineering (Education Ministry), College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China.
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15
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Olivera ER, Luengo JM. Steroids as Environmental Compounds Recalcitrant to Degradation: Genetic Mechanisms of Bacterial Biodegradation Pathways. Genes (Basel) 2019; 10:genes10070512. [PMID: 31284586 PMCID: PMC6678751 DOI: 10.3390/genes10070512] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Revised: 07/02/2019] [Accepted: 07/03/2019] [Indexed: 12/29/2022] Open
Abstract
Steroids are perhydro-1,2-cyclopentanophenanthrene derivatives that are almost exclusively synthesised by eukaryotic organisms. Since the start of the Anthropocene, the presence of these molecules, as well as related synthetic compounds (ethinylestradiol, dexamethasone, and others), has increased in different habitats due to farm and municipal effluents and discharge from the pharmaceutical industry. In addition, the highly hydrophobic nature of these molecules, as well as the absence of functional groups, makes them highly resistant to biodegradation. However, some environmental bacteria are able to modify or mineralise these compounds. Although steroid-metabolising bacteria have been isolated since the beginning of the 20th century, the genetics and catabolic pathways used have only been characterised in model organisms in the last few decades. Here, the metabolic alternatives used by different bacteria to metabolise steroids (e.g., cholesterol, bile acids, testosterone, and other steroid hormones), as well as the organisation and conservation of the genes involved, are reviewed.
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Affiliation(s)
- Elías R Olivera
- Departamento Biología Molecular (Área Bioquímica y Biología Molecular), Universidad de León, 24007 León, Spain.
| | - José M Luengo
- Departamento Biología Molecular (Área Bioquímica y Biología Molecular), Universidad de León, 24007 León, Spain
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Microbial Functional Responses to Cholesterol Catabolism in Denitrifying Sludge. mSystems 2018; 3:mSystems00113-18. [PMID: 30417110 PMCID: PMC6208644 DOI: 10.1128/msystems.00113-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 10/11/2018] [Indexed: 01/08/2023] Open
Abstract
Steroids are ubiquitous and abundant natural compounds that display recalcitrance. Biodegradation via sludge communities in wastewater treatment plants is the primary removal process for steroids. To date, compared to studies for aerobic steroid degradation, the knowledge of anaerobic degradation of steroids has been based on only a few model organisms. Due to the increase of anthropogenic impacts, steroid inputs may affect microbial diversity and functioning in ecosystems. Here, we first investigated microbial functional responses to cholesterol, the most abundant steroid in sludge, at the community level. Our metagenomic and metatranscriptomic analyses revealed that the capacities for cholesterol approach, uptake, and degradation are unique traits of certain low-abundance betaproteobacteria, indicating the importance of the rare biosphere in bioremediation. Apparent expression of genes involved in cofactor de novo synthesis and salvage pathways suggests that these micronutrients play important roles for cholesterol degradation in sludge communities. The 2,3-seco pathway, the pathway for anaerobic cholesterol degradation, has been established in the denitrifying betaproteobacterium Sterolibacterium denitrificans. However, knowledge of how microorganisms respond to cholesterol at the community level is elusive. Here, we applied mesocosm incubation and 16S rRNA sequencing to reveal that, in denitrifying sludge communities, three betaproteobacterial operational taxonomic units (OTUs) with low (94% to 95%) 16S rRNA sequence similarity to Stl. denitrificans are cholesterol degraders and members of the rare biosphere. Metatranscriptomic and metabolite analyses show that these degraders adopt the 2,3-seco pathway to sequentially catalyze the side chain and sterane of cholesterol and that two molybdoenzymes—steroid C25 dehydrogenase and 1-testosterone dehydrogenase/hydratase—are crucial for these bioprocesses, respectively. The metatranscriptome further suggests that these betaproteobacterial degraders display chemotaxis and motility toward cholesterol and that FadL-like transporters may be the key components for substrate uptake. Also, these betaproteobacteria are capable of transporting micronutrients and synthesizing cofactors essential for cellular metabolism and cholesterol degradation; however, the required cobalamin is possibly provided by cobalamin-de novo-synthesizing gamma-, delta-, and betaproteobacteria via the salvage pathway. Overall, our results indicate that the ability to degrade cholesterol in sludge communities is reserved for certain rare biosphere members and that C25 dehydrogenase can serve as a biomarker for sterol degradation in anoxic environments. IMPORTANCE Steroids are ubiquitous and abundant natural compounds that display recalcitrance. Biodegradation via sludge communities in wastewater treatment plants is the primary removal process for steroids. To date, compared to studies for aerobic steroid degradation, the knowledge of anaerobic degradation of steroids has been based on only a few model organisms. Due to the increase of anthropogenic impacts, steroid inputs may affect microbial diversity and functioning in ecosystems. Here, we first investigated microbial functional responses to cholesterol, the most abundant steroid in sludge, at the community level. Our metagenomic and metatranscriptomic analyses revealed that the capacities for cholesterol approach, uptake, and degradation are unique traits of certain low-abundance betaproteobacteria, indicating the importance of the rare biosphere in bioremediation. Apparent expression of genes involved in cofactor de novo synthesis and salvage pathways suggests that these micronutrients play important roles for cholesterol degradation in sludge communities.
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Szaleniec M, Wojtkiewicz AM, Bernhardt R, Borowski T, Donova M. Bacterial steroid hydroxylases: enzyme classes, their functions and comparison of their catalytic mechanisms. Appl Microbiol Biotechnol 2018; 102:8153-8171. [PMID: 30032434 PMCID: PMC6153880 DOI: 10.1007/s00253-018-9239-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 07/10/2018] [Accepted: 07/10/2018] [Indexed: 12/22/2022]
Abstract
The steroid superfamily includes a wide range of compounds that are essential for living organisms of the animal and plant kingdoms. Structural modifications of steroids highly affect their biological activity. In this review, we focus on hydroxylation of steroids by bacterial hydroxylases, which take part in steroid catabolic pathways and play an important role in steroid degradation. We compare three distinct classes of metalloenzymes responsible for aerobic or anaerobic hydroxylation of steroids, namely: cytochrome P450, Rieske-type monooxygenase 3-ketosteroid 9α-hydroxylase, and molybdenum-containing steroid C25 dehydrogenases. We analyze the available literature data on reactivity, regioselectivity, and potential application of these enzymes in organic synthesis of hydroxysteroids. Moreover, we describe mechanistic hypotheses proposed for all three classes of enzymes along with experimental and theoretical evidences, which have provided grounds for their formulation. In case of the 3-ketosteroid 9α-hydroxylase, such a mechanistic hypothesis is formulated for the first time in the literature based on studies conducted for other Rieske monooxygenases. Finally, we provide comparative analysis of similarities and differences in the reaction mechanisms utilized by bacterial steroid hydroxylases.
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Affiliation(s)
- Maciej Szaleniec
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Niezapominajek 8, 30-239, Kraków, Poland.
| | - Agnieszka M Wojtkiewicz
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Niezapominajek 8, 30-239, Kraków, Poland
| | - Rita Bernhardt
- Lehrstuhl für Biochemie, Universität des Saarlandes, Campus B2 2, 66123, Saarbrücken, Germany
| | - Tomasz Borowski
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Niezapominajek 8, 30-239, Kraków, Poland
| | - Marina Donova
- G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino, Moscow Oblast, 142290, Russia
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