1
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Belle R, Saraç H, Salah E, Bhushan B, Szykowska A, Roper G, Tumber A, Kriaucionis S, Burgess-Brown N, Schofield CJ, Brown T, Kawamura A. Focused Screening Identifies Different Sensitivities of Human TET Oxygenases to the Oncometabolite 2-Hydroxyglutarate. J Med Chem 2024; 67:4525-4540. [PMID: 38294854 PMCID: PMC10983004 DOI: 10.1021/acs.jmedchem.3c01820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 12/10/2023] [Accepted: 01/04/2024] [Indexed: 02/01/2024]
Abstract
Ten-eleven translocation enzymes (TETs) are Fe(II)/2-oxoglutarate (2OG) oxygenases that catalyze the sequential oxidation of 5-methylcytosine to 5-hydroxymethylcytosine, 5-formylcytosine, and 5-carboxylcytosine in eukaryotic DNA. Despite their roles in epigenetic regulation, there is a lack of reported TET inhibitors. The extent to which 2OG oxygenase inhibitors, including clinically used inhibitors and oncometabolites, modulate DNA modifications via TETs has been unclear. Here, we report studies on human TET1-3 inhibition by a set of 2OG oxygenase-focused inhibitors, employing both enzyme-based and cellular assays. Most inhibitors manifested similar potencies for TET1-3 and caused increases in cellular 5hmC levels. (R)-2-Hydroxyglutarate, an oncometabolite elevated in isocitrate dehydrogenase mutant cancer cells, showed different degrees of inhibition, with TET1 being less potently inhibited than TET3 and TET2, potentially reflecting the proposed role of TET2 mutations in tumorigenesis. The results highlight the tractability of TETs as drug targets and provide starting points for selective inhibitor design.
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Affiliation(s)
- Roman Belle
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, OX1 3TA Oxford, United Kingdom
- Chemistry
− School of Natural and Environmental Sciences, Bedson Building, Newcastle University, NE1 7RU Newcastle upon Tyne, United Kingdom
| | - Hilal Saraç
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, OX1 3TA Oxford, United Kingdom
- Chemistry
− School of Natural and Environmental Sciences, Bedson Building, Newcastle University, NE1 7RU Newcastle upon Tyne, United Kingdom
- Radcliffe
Department of Medicine, Division of Cardiovascular Medicine, University of Oxford, Wellcome Trust Centre for Human
Genetics, Roosevelt Drive, OX3 7BN Oxford, United Kingdom
| | - Eidarus Salah
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, OX1 3TA Oxford, United Kingdom
- Centre
for Medicines Discovery, University of Oxford, Old Road Campus Research Building,
Roosevelt Drive, OX3 7DQ Oxford, United Kingdom
| | - Bhaskar Bhushan
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, OX1 3TA Oxford, United Kingdom
- Radcliffe
Department of Medicine, Division of Cardiovascular Medicine, University of Oxford, Wellcome Trust Centre for Human
Genetics, Roosevelt Drive, OX3 7BN Oxford, United Kingdom
| | - Aleksandra Szykowska
- Centre
for Medicines Discovery, University of Oxford, Old Road Campus Research Building,
Roosevelt Drive, OX3 7DQ Oxford, United Kingdom
| | - Grace Roper
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, OX1 3TA Oxford, United Kingdom
- Chemistry
− School of Natural and Environmental Sciences, Bedson Building, Newcastle University, NE1 7RU Newcastle upon Tyne, United Kingdom
| | - Anthony Tumber
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, OX1 3TA Oxford, United Kingdom
- Ineos Oxford
Institute for Antimicrobial Research, University
of Oxford, 12 Mansfield Road, OX1 3TA Oxford, United Kingdom
| | - Skirmantas Kriaucionis
- Ludwig
Institute for Cancer Research, Nuffield Department of Medicine, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, OX3 7DQ Oxford, United Kingdom
| | - Nicola Burgess-Brown
- Centre
for Medicines Discovery, University of Oxford, Old Road Campus Research Building,
Roosevelt Drive, OX3 7DQ Oxford, United Kingdom
| | - Christopher J. Schofield
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, OX1 3TA Oxford, United Kingdom
- Ineos Oxford
Institute for Antimicrobial Research, University
of Oxford, 12 Mansfield Road, OX1 3TA Oxford, United Kingdom
| | - Tom Brown
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, OX1 3TA Oxford, United Kingdom
| | - Akane Kawamura
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, OX1 3TA Oxford, United Kingdom
- Chemistry
− School of Natural and Environmental Sciences, Bedson Building, Newcastle University, NE1 7RU Newcastle upon Tyne, United Kingdom
- Radcliffe
Department of Medicine, Division of Cardiovascular Medicine, University of Oxford, Wellcome Trust Centre for Human
Genetics, Roosevelt Drive, OX3 7BN Oxford, United Kingdom
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2
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Zhou B, Utjapimuk S, Yan K, Dubey R, Kikuchi T, Mitsuhashi T, Fujita M. Rapid Analysis of Trace Amounts of Amino Acid Derivatives by a Formyl Group-Installed Crystalline Sponge. Chem Asian J 2023:e202300969. [PMID: 38059774 DOI: 10.1002/asia.202300969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 12/07/2023] [Accepted: 12/07/2023] [Indexed: 12/08/2023]
Abstract
The Industries need techniques for the rapid structure analysis of amino acid derivatives. The amino acid derivatives are sometimes produced as impurities in the industrial production processes, and cause toxicity problems. Herein, we report the crystalline sponge (CS) method analysis of variety of amino acids using a formyl group installed CS crystal. Most amino acids possess a primary amino group, which can form Schiff-base with the formyl group under mild conditions. Thus, the formyl group installed CS crystal can efficiently capture the amino acids via Schiff-base formation. We successfully analyzed derivatives of 18 proteogenic amino acids, 6 non-proteogenic amino acids, and 4 dipeptides using the formyl group installed CS. We thus believe that the protocols shown in this study would serve the need of the industries.
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Affiliation(s)
- Boyu Zhou
- Department of Applied Chemistry, School of Engineering, The University of Tokyo Mitsui Link Lab Kashiwanoha 1, FS CREATION, 6-6-2 Kashiwanoha, Kashiwa, Chiba, 277-0882, Japan
| | - Soravit Utjapimuk
- Department of Applied Chemistry, School of Engineering, The University of Tokyo Mitsui Link Lab Kashiwanoha 1, FS CREATION, 6-6-2 Kashiwanoha, Kashiwa, Chiba, 277-0882, Japan
| | - KaKing Yan
- Department of Applied Chemistry, School of Engineering, The University of Tokyo Mitsui Link Lab Kashiwanoha 1, FS CREATION, 6-6-2 Kashiwanoha, Kashiwa, Chiba, 277-0882, Japan
| | - Ritesh Dubey
- Department of Applied Chemistry, School of Engineering, The University of Tokyo Mitsui Link Lab Kashiwanoha 1, FS CREATION, 6-6-2 Kashiwanoha, Kashiwa, Chiba, 277-0882, Japan
| | - Takashi Kikuchi
- Rigaku Corporation, 3-9-12 Matsubara-cho, Akishima-shi, Tokyo, 196-8666, Japan
| | - Takaaki Mitsuhashi
- Division of Advanced Molecular Science, Institute for Molecular Science (IMS), 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan
| | - Makoto Fujita
- Department of Applied Chemistry, School of Engineering, The University of Tokyo Mitsui Link Lab Kashiwanoha 1, FS CREATION, 6-6-2 Kashiwanoha, Kashiwa, Chiba, 277-0882, Japan
- Division of Advanced Molecular Science, Institute for Molecular Science (IMS), 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan
- Tokyo College, U-Tokyo Institutes for Advanced Study, The University of Tokyo Mitsui Link Lab Kashiwanoha 1, FS CREATION, 6-6-2 Kashiwanoha, Kashiwa, Chiba, 277-0882, Japan
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3
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Multifunctional Enzymes in Microbial Secondary Metabolic Processes. Catalysts 2023. [DOI: 10.3390/catal13030581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/15/2023] Open
Abstract
Microorganisms possess a strong capacity for secondary metabolite synthesis, which is represented by tightly controlled networks. The absence of any enzymes leads to a change in the original metabolic pathway, with a decrease in or even elimination of a synthetic product, which is not permissible under conditions of normal life activities of microorganisms. In order to improve the efficiency of secondary metabolism, organisms have evolved multifunctional enzymes (MFEs) that can catalyze two or more kinds of reactions via multiple active sites. However, instead of interfering, the multifunctional catalytic properties of MFEs facilitate the biosynthetic process. Among the numerous MFEs considered of vital importance in the life activities of living organisms are the synthases involved in assembling the backbone of compounds using different substrates and modifying enzymes that confer the final activity of compounds. In this paper, we review MFEs in terms of both synthetic and post-modifying enzymes involved in secondary metabolic biosynthesis, focusing on polyketides, non-ribosomal peptides, terpenoids, and a wide range of cytochrome P450s(CYP450s), and provide an overview and describe the recent progress in the research on MFEs.
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4
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Parkinson EI, Lakkis HG, Alwali AA, Metcalf MEM, Modi R, Metcalf WW. An Unusual Oxidative Rearrangement Catalyzed by a Divergent Member of the 2-Oxoglutarate-Dependent Dioxygenase Superfamily during Biosynthesis of Dehydrofosmidomycin. Angew Chem Int Ed Engl 2022; 61:e202206173. [PMID: 35588368 PMCID: PMC9296572 DOI: 10.1002/anie.202206173] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Indexed: 12/20/2022]
Abstract
The biosynthesis of the natural product dehydrofosmidomycin involves an unusual transformation in which 2-(trimethylamino)ethylphosphonate is rearranged, desaturated and demethylated by the enzyme DfmD, a divergent member of the 2-oxoglutarate-dependent dioxygenase superfamily. Although other members of this enzyme family catalyze superficially similar transformations, the combination of all three reactions in a single enzyme has not previously been observed. By characterizing the products of in vitro reactions with labeled and unlabeled substrates, we show that DfmD performs this transformation in two steps, with the first involving desaturation of the substrate to form 2-(trimethylamino)vinylphosphonate, and the second involving rearrangement and demethylation to form methyldehydrofosmidomycin. These data reveal significant differences from the desaturation and rearrangement reactions catalyzed by other family members.
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Affiliation(s)
- Elizabeth I. Parkinson
- Institute for Genomic BiologyUniversity of Illinois at Urbana-Champaign1206 W. Gregory Dr.UrbanaIL 61801USA
- Department of ChemistryPurdue UniversityHerbert C. Brown Laboratory of Chemistry, Room 4103E560 Oval Drive, Box 59West LafayetteIN 47907USA
- Department of Medicinal Chemistry and Molecular PharmacologyPurdue UniversityHerbert C. Brown Laboratory of Chemistry, Room 4103E560 Oval Drive, Box 59West LafayetteIN 47907USA
| | - Hani G. Lakkis
- Department of ChemistryPurdue UniversityHerbert C. Brown Laboratory of Chemistry, Room 4103E560 Oval Drive, Box 59West LafayetteIN 47907USA
| | - Amir A. Alwali
- Department of ChemistryPurdue UniversityHerbert C. Brown Laboratory of Chemistry, Room 4103E560 Oval Drive, Box 59West LafayetteIN 47907USA
| | - Mary Elizabeth M. Metcalf
- Institute for Genomic BiologyUniversity of Illinois at Urbana-Champaign1206 W. Gregory Dr.UrbanaIL 61801USA
- Department of MicrobiologyUniversity of Illinois at Urbana-Champaign, B103C&LSL601 S. GoodwinUrbanaIL 61801USA
| | - Ramya Modi
- Department of ChemistryPurdue UniversityHerbert C. Brown Laboratory of Chemistry, Room 4103E560 Oval Drive, Box 59West LafayetteIN 47907USA
| | - William W. Metcalf
- Institute for Genomic BiologyUniversity of Illinois at Urbana-Champaign1206 W. Gregory Dr.UrbanaIL 61801USA
- Department of MicrobiologyUniversity of Illinois at Urbana-Champaign, B103C&LSL601 S. GoodwinUrbanaIL 61801USA
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5
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Parkinson EI, Lakkis HG, Alwali AA, Metcalf MEM, Modi R, Metcalf WW. An Unusual Oxidative Rearrangement Catalyzed by a Divergent Member of the 2‐Oxoglutarate‐Dependent Dioxygenase Superfamily during Biosynthesis of Dehydrofosmidomycin. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202206173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | | | - Ramya Modi
- Purdue University Chemistry UNITED STATES
| | - William W. Metcalf
- University of Illinois Urbana-Champaign Microbiology 601 S. GoodwinB103 CLSL 61801 Urbana UNITED STATES
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6
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Song S, Jiang Y, Chen R, Su W, Liang W, Yang D, Li J, Zhang W, Gao S, Yuan B, Qu G, Sun Z. Whole-cell Biotransformation of Penicillin G by a Three-enzyme Co-expression System with Engineered Deacetoxycephalosporin C Synthase. Chembiochem 2022; 23:e202200179. [PMID: 35384232 DOI: 10.1002/cbic.202200179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 04/06/2022] [Indexed: 11/10/2022]
Abstract
Deacetoxycephalosporin C synthase (DAOCS) catalyzes the tranformation of penicillin G to phenylacetyl-7-aminodeacetoxycephalosporanic acid (G-7-ADCA) in dependence on 2-oxoglutarate (2OG). However, the low activity of DAOCS and the expense of 2OG restricted the practical application in the production of G-7-ADCA. Herein, a rational design campaign was performed on a DAOCS from Streptomyces clavuligerus (scDAOCS) in the quest to construct novel expandases. The resulting mutants showed 25~58% increase in activity compared to the template. The dominant DAOCS variants were then embeded into a three-enzyme co-expression system, consisting of a catalase and a L-glutamic oxidase for the generation of 2OG, to convert penicillin G into G-7-ADCA in E. coli . The engineered whole-cell enzyme cascade was applied on an up scaled reaction, exhibiting a yield of G-7-ADCA up to 39.21 mM (14.6 g·L -1 ) with a conversion of 78.42 mol%. This work highlights the potential of the integrated whole-cell system that may inspire further research on green and efficient production of 7-ADCA.
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Affiliation(s)
- Shiyi Song
- Tianjin Institute of Industrial Biotechnology Chinese Academy of Sciences, TIB, CHINA
| | - Yingying Jiang
- Tianjin Institute of Industrial Biotechnology Chinese Academy of Sciences, TIB, CHINA
| | - Ruidong Chen
- Tianjin Institute of Industrial Biotechnology Chinese Academy of Sciences, TIB, CHINA
| | - Wencheng Su
- Tianjin Institute of Industrial Biotechnology Chinese Academy of Sciences, TIB, 32 West 7th Avenue, Tianjin Airport Economic Area, 300308, Tianjin, CHINA
| | - Weinan Liang
- Tianjin Institute of Industrial Biotechnology Chinese Academy of Sciences, TIB, CHINA
| | - Dameng Yang
- Tianjin Institute of Industrial Biotechnology Chinese Academy of Sciences, TIB, 32 West 7th Avenue, Tianjin Airport Economic Area, 300308, CHINA
| | - Jincheng Li
- Tianjin Institute of Industrial Biotechnology Chinese Academy of Sciences, TIB, CHINA
| | - Wuyuan Zhang
- Tianjin Institute of Industrial Biotechnology Chinese Academy of Sciences, TIB, CHINA
| | - Shushan Gao
- Tianjin Institute of Industrial Biotechnology Chinese Academy of Sciences, TIB, CHINA
| | - Bo Yuan
- Tianjin Institute of Industrial Biotechnology Chinese Academy of Sciences, TIB, CHINA
| | - Ge Qu
- Tianjin Institute of Industrial Biotechnology Chinese Academy of Sciences, TIB, CHINA
| | - Zhoutong Sun
- Tianjin Institute of Industrial Biotechnology Chinese Academy of Sciences, National Enyzme Engineering Lab, 32 West 7th Avenue, Tianjin Airport Economic Area, 300308, Tianjin, CHINA
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7
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Wojdyla Z, Borowski T. Properties of the Reactants and Their Interactions within and with the Enzyme Binding Cavity Determine Reaction Selectivities. The Case of Fe(II)/2-Oxoglutarate Dependent Enzymes. Chemistry 2022; 28:e202104106. [PMID: 34986268 DOI: 10.1002/chem.202104106] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Indexed: 12/12/2022]
Abstract
Fe(II)/2-oxoglutarate dependent dioxygenases (ODDs) share a double stranded beta helix (DSBH) fold and utilise a common reactive intermediate, ferryl species, to catalyse oxidative transformations of substrates. Despite the structural similarities, ODDs accept a variety of substrates and facilitate a wide range of reactions, that is hydroxylations, desaturations, (oxa)cyclisations and ring rearrangements. In this review we present and discuss the factors contributing to the observed (regio)selectivities of ODDs. They span from inherent properties of the reactants, that is, substrate molecule and iron cofactor, to the interactions between the substrate and the enzyme's binding cavity; the latter can counterbalance the effect of the former. Based on results of both experimental and computational studies dedicated to ODDs, we also line out the properties of the reactants which promote reaction outcomes other than the "default" hydroxylation. It turns out that the reaction selectivity depends on a delicate balance of interactions between the components of the investigated system.
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Affiliation(s)
- Zuzanna Wojdyla
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Kraków, Niezapominajek 8, 30239 Krakow, Poland
| | - Tomasz Borowski
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Kraków, Niezapominajek 8, 30239 Krakow, Poland
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8
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Niu X, Zhang J, Xue X, Wang D, Wang L, Gao Q. Deacetoxycephalosporin C synthase (expandase): Research progress and application potential. Synth Syst Biotechnol 2021; 6:396-401. [PMID: 34901478 PMCID: PMC8626558 DOI: 10.1016/j.synbio.2021.11.001] [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: 11/09/2020] [Revised: 11/04/2021] [Accepted: 11/05/2021] [Indexed: 12/02/2022] Open
Abstract
Cephalosporins play an indispensable role against bacterial infections. Deacetyloxycephalosporin C synthase (DAOCS), also called expandase, is a key enzyme in cephalosporin biosynthesis that epoxides penicillin to form the hexavalent thiazide ring of cephalosporin. DAOCS in fungus Acremonium chrysogenum was identified as a bifunctional enzyme with both ring expansion and hydroxylation, whereas two separate enzymes in bacteria catalyze these two reactions. In this review, we briefly summarize its source and function, improvement of the conversion rate of penicillin to deacetyloxycephalosporin C through enzyme modification, crystallography features, the prediction of the active site, and application perspective.
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Affiliation(s)
- Xiaofan Niu
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China
| | - Jian Zhang
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China.,Tianjin Microbial Metabolism and Fermentation Process Control Technology Engineering Center, Tianjin, 300457, China
| | - Xianli Xue
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China.,Tianjin Microbial Metabolism and Fermentation Process Control Technology Engineering Center, Tianjin, 300457, China
| | - Depei Wang
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China.,National Demonstration Center for Experimental Bioengineering Education (Tianjin University of Science and Technology), Tianjin, 300457, China.,Tianjin Microbial Metabolism and Fermentation Process Control Technology Engineering Center, Tianjin, 300457, China
| | - Lin Wang
- College of Artificial Intelligence, Tianjin University of Science and Technology, Tianjin, 300457, China
| | - Qiang Gao
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China.,National Demonstration Center for Experimental Bioengineering Education (Tianjin University of Science and Technology), Tianjin, 300457, China.,Tianjin Microbial Metabolism and Fermentation Process Control Technology Engineering Center, Tianjin, 300457, China
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9
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Solomon EI, DeWeese DE, Babicz JT. Mechanisms of O 2 Activation by Mononuclear Non-Heme Iron Enzymes. Biochemistry 2021; 60:3497-3506. [PMID: 34266238 PMCID: PMC8768060 DOI: 10.1021/acs.biochem.1c00370] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Two major subclasses of mononuclear non-heme ferrous enzymes use two electron-donating organic cofactors (α-ketoglutarate or pterin) to activate O2 to form FeIV═O intermediates that further react with their substrates through hydrogen atom abstraction or electrophilic aromatic substitution. New spectroscopic methodologies have been developed, enabling the study of the active sites in these enzymes and their oxygen intermediates. Coupled to electronic structure calculations, the results of these spectroscopies provide fundamental insight into mechanism. This Perspective summarizes the results of these studies in elucidating the mechanism of dioxygen activation to form the FeIV═O intermediate and the geometric and electronic structure of this intermediate that enables its high reactivity and selectivity in product formation.
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Affiliation(s)
- Edward I. Solomon
- Department of Chemistry, Stanford University, 333 Campus Dr. Stanford, CA, 94305, United States,SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA, 94025, United States
| | - Dory E. DeWeese
- Department of Chemistry, Stanford University, 333 Campus Dr. Stanford, CA, 94305, United States
| | - Jeffrey T. Babicz
- Department of Chemistry, Stanford University, 333 Campus Dr. Stanford, CA, 94305, United States
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10
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Wang Y, Shi Y, Li K, Yang D, Liu N, Zhang L, Zhao L, Zhang X, Liu Y, Gao L, Xia T, Wang P. Roles of the 2-Oxoglutarate-Dependent Dioxygenase Superfamily in the Flavonoid Pathway: A Review of the Functional Diversity of F3H, FNS I, FLS, and LDOX/ANS. Molecules 2021; 26:molecules26216745. [PMID: 34771153 PMCID: PMC8588099 DOI: 10.3390/molecules26216745] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 11/01/2021] [Accepted: 11/02/2021] [Indexed: 11/25/2022] Open
Abstract
The 2-oxoglutarate-dependent dioxygenase (2-OGD) superfamily is one of the largest protein families in plants. The main oxidation reactions they catalyze in plants are hydroxylation, desaturation, demethylation, epimerization, and halogenation. Four members of the 2-OGD superfamily, i.e., flavonone 3β-hydroxylase (F3H), flavones synthase I (FNS I), flavonol synthase (FLS), and anthocyanidin synthase (ANS)/leucoanthocyanidin dioxygenase (LDOX), are present in the flavonoid pathway, catalyzing hydroxylation and desaturation reactions. In this review, we summarize the recent research progress on these proteins, from the discovery of their enzymatic activity, to their functional verification, to the analysis of the response they mediate in plants towards adversity. Substrate diversity analysis indicated that F3H, FNS Ⅰ, ANS/LDOX, and FLS perform their respective dominant functions in the flavonoid pathway, despite the presence of functional redundancy among them. The phylogenetic tree classified two types of FNS Ⅰ, one mainly performing FNS activity, and the other, a new type of FNS present in angiosperms, mainly involved in C-5 hydroxylation of SA. Additionally, a new class of LDOXs is highlighted, which can catalyze the conversion of (+)-catechin to cyanidin, further influencing the starter and extension unit composition of proanthocyanidins (PAs). The systematical description of the functional diversity and evolutionary relationship among these enzymes can facilitate the understanding of their impacts on plant metabolism. On the other hand, it provides molecular genetic evidence of the chemical evolution of flavonoids from lower to higher plants, promoting plant adaptation to harsh environments.
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Affiliation(s)
- Yueyue Wang
- College of Horticulture, Qingdao Agricultural University, Qingdao 266109, China; (Y.W.); (K.L.); (D.Y.); (N.L.); (L.Z.); (X.Z.)
| | - Yufeng Shi
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei 230036, China;
| | - Kaiyuan Li
- College of Horticulture, Qingdao Agricultural University, Qingdao 266109, China; (Y.W.); (K.L.); (D.Y.); (N.L.); (L.Z.); (X.Z.)
| | - Dong Yang
- College of Horticulture, Qingdao Agricultural University, Qingdao 266109, China; (Y.W.); (K.L.); (D.Y.); (N.L.); (L.Z.); (X.Z.)
| | - Nana Liu
- College of Horticulture, Qingdao Agricultural University, Qingdao 266109, China; (Y.W.); (K.L.); (D.Y.); (N.L.); (L.Z.); (X.Z.)
| | - Lingjie Zhang
- School of Life Science, Anhui Agricultural University, Hefei 230036, China; (L.Z.); (Y.L.)
| | - Lei Zhao
- College of Horticulture, Qingdao Agricultural University, Qingdao 266109, China; (Y.W.); (K.L.); (D.Y.); (N.L.); (L.Z.); (X.Z.)
| | - Xinfu Zhang
- College of Horticulture, Qingdao Agricultural University, Qingdao 266109, China; (Y.W.); (K.L.); (D.Y.); (N.L.); (L.Z.); (X.Z.)
| | - Yajun Liu
- School of Life Science, Anhui Agricultural University, Hefei 230036, China; (L.Z.); (Y.L.)
| | - Liping Gao
- School of Life Science, Anhui Agricultural University, Hefei 230036, China; (L.Z.); (Y.L.)
- Correspondence: (L.G.); (T.X.); (P.W.)
| | - Tao Xia
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei 230036, China;
- Correspondence: (L.G.); (T.X.); (P.W.)
| | - Peiqiang Wang
- College of Horticulture, Qingdao Agricultural University, Qingdao 266109, China; (Y.W.); (K.L.); (D.Y.); (N.L.); (L.Z.); (X.Z.)
- Correspondence: (L.G.); (T.X.); (P.W.)
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11
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Wei S, Zhang W, Fu R, Zhang Y. Genome-wide characterization of 2-oxoglutarate and Fe(II)-dependent dioxygenase family genes in tomato during growth cycle and their roles in metabolism. BMC Genomics 2021; 22:126. [PMID: 33602133 PMCID: PMC7891033 DOI: 10.1186/s12864-021-07434-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 02/10/2021] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND 2-Oxoglutarate and Fe(II)-dependent dioxygenases (2ODDs) belong to the 2-oxoglutarate-dependent dioxygenase (2OGD) superfamily and are involved in various vital metabolic pathways of plants at different developmental stages. These proteins have been extensively investigated in multiple model organisms. However, these enzymes have not been systematically analyzed in tomato. In addition, type I flavone synthase (FNSI) belongs to the 2ODD family and contributes to the biosynthesis of flavones, but this protein has not been characterized in tomato. RESULTS A total of 131 2ODDs from tomato were identified and divided into seven clades by phylogenetic classification. The Sl2ODDs in the same clade showed similar intron/exon distributions and conserved motifs. The Sl2ODDs were unevenly distributed across the 12 chromosomes, with different expression patterns among major tissues and at different developmental stages of the tomato growth cycle. We characterized several Sl2ODDs and their expression patterns involved in various metabolic pathways, such as gibberellin biosynthesis and catabolism, ethylene biosynthesis, steroidal glycoalkaloid biosynthesis, and flavonoid metabolism. We found that the Sl2ODD expression patterns were consistent with their functions during the tomato growth cycle. These results indicated the significance of Sl2ODDs in tomato growth and metabolism. Based on this genome-wide analysis of Sl2ODDs, we screened six potential FNSI genes using a phylogenetic tree and coexpression analysis. However, none of them exhibited FNSI activity. CONCLUSIONS Our study provided a comprehensive understanding of the tomato 2ODD family and demonstrated the significant roles of these family members in plant metabolism. We also suggest that no FNSI genes in tomato contribute to the biosynthesis of flavones.
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Affiliation(s)
- Shuo Wei
- grid.13291.380000 0001 0807 1581Key Laboratory of Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, No.24 South Section 1, Yihuan Road, Chengdu, China
| | - Wen Zhang
- grid.13291.380000 0001 0807 1581Key Laboratory of Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, No.24 South Section 1, Yihuan Road, Chengdu, China
| | - Rao Fu
- grid.13291.380000 0001 0807 1581Key Laboratory of Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, No.24 South Section 1, Yihuan Road, Chengdu, China
| | - Yang Zhang
- grid.13291.380000 0001 0807 1581Key Laboratory of Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, No.24 South Section 1, Yihuan Road, Chengdu, China
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12
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Copeland RA, Davis KM, Shoda TKC, Blaesi EJ, Boal AK, Krebs C, Bollinger JM. An Iron(IV)-Oxo Intermediate Initiating l-Arginine Oxidation but Not Ethylene Production by the 2-Oxoglutarate-Dependent Oxygenase, Ethylene-Forming Enzyme. J Am Chem Soc 2021; 143:2293-2303. [PMID: 33522811 DOI: 10.1021/jacs.0c10923] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Ethylene-forming enzyme (EFE) is an ambifunctional iron(II)- and 2-oxoglutarate-dependent (Fe/2OG) oxygenase. In its major (EF) reaction, it converts carbons 1, 2, and 5 of 2OG to CO2 and carbons 3 and 4 to ethylene, a four-electron oxidation drastically different from the simpler decarboxylation of 2OG to succinate mediated by all other Fe/2OG enzymes. EFE also catalyzes a minor reaction, in which the normal decarboxylation is coupled to oxidation of l-arginine (a required activator for the EF pathway), resulting in its conversion to l-glutamate semialdehyde and guanidine. Here we show that, consistent with precedent, the l-Arg-oxidation (RO) pathway proceeds via an iron(IV)-oxo (ferryl) intermediate. Use of 5,5-[2H2]-l-Arg slows decay of the ferryl complex by >16-fold, implying that RO is initiated by hydrogen-atom transfer (HAT) from C5. That this large substrate deuterium kinetic isotope effect has no impact on the EF:RO partition ratio implies that the same ferryl intermediate cannot be on the EF pathway; the pathways must diverge earlier. Consistent with this conclusion, the variant enzyme bearing the Asp191Glu ligand substitution accumulates ∼4 times as much of the ferryl complex as the wild-type enzyme and exhibits a ∼40-fold diminished EF:RO partition ratio. The selective detriment of this nearly conservative substitution to the EF pathway implies that it has unusually stringent stereoelectronic requirements. An active-site, like-charge guanidinium pair, which involves the l-Arg substrate/activator and is unique to EFE among four crystallographically characterized l-Arg-modifying Fe/2OG oxygenases, may serve to selectively stabilize the transition state leading to the unique EF branch.
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13
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Liu T, Abboud MI, Chowdhury R, Tumber A, Hardy AP, Lippl K, Lohans CT, Pires E, Wickens J, McDonough MA, West CM, Schofield CJ. Biochemical and biophysical analyses of hypoxia sensing prolyl hydroxylases from Dictyostelium discoideum and Toxoplasma gondii. J Biol Chem 2020; 295:16545-16561. [PMID: 32934009 PMCID: PMC7864055 DOI: 10.1074/jbc.ra120.013998] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 08/14/2020] [Indexed: 12/30/2022] Open
Abstract
In animals, the response to chronic hypoxia is mediated by prolyl hydroxylases (PHDs) that regulate the levels of hypoxia-inducible transcription factor α (HIFα). PHD homologues exist in other types of eukaryotes and prokaryotes where they act on non HIF substrates. To gain insight into the factors underlying different PHD substrates and properties, we carried out biochemical and biophysical studies on PHD homologues from the cellular slime mold, Dictyostelium discoideum, and the protozoan parasite, Toxoplasma gondii, both lacking HIF. The respective prolyl-hydroxylases (DdPhyA and TgPhyA) catalyze prolyl-hydroxylation of S-phase kinase-associated protein 1 (Skp1), a reaction enabling adaptation to different dioxygen availability. Assays with full-length Skp1 substrates reveal substantial differences in the kinetic properties of DdPhyA and TgPhyA, both with respect to each other and compared with human PHD2; consistent with cellular studies, TgPhyA is more active at low dioxygen concentrations than DdPhyA. TgSkp1 is a DdPhyA substrate and DdSkp1 is a TgPhyA substrate. No cross-reactivity was detected between DdPhyA/TgPhyA substrates and human PHD2. The human Skp1 E147P variant is a DdPhyA and TgPhyA substrate, suggesting some retention of ancestral interactions. Crystallographic analysis of DdPhyA enables comparisons with homologues from humans, Trichoplax adhaerens, and prokaryotes, informing on differences in mobile elements involved in substrate binding and catalysis. In DdPhyA, two mobile loops that enclose substrates in the PHDs are conserved, but the C-terminal helix of the PHDs is strikingly absent. The combined results support the proposal that PHD homologues have evolved kinetic and structural features suited to their specific sensing roles.
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Affiliation(s)
- Tongri Liu
- Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
| | - Martine I Abboud
- Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
| | | | - Anthony Tumber
- Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
| | - Adam P Hardy
- Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
| | - Kerstin Lippl
- Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
| | | | - Elisabete Pires
- Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
| | - James Wickens
- Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
| | | | - Christopher M West
- Department of Biochemistry and Molecular Biology, Complex Carbohydrate Research Center, Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA
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14
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Liu Y, Shi J, Liu Y. Mechanistic Insights into the Oxidative Ring Expansion from Penicillin N to Deacetoxycephalosporin C Catalyzed by a Nonheme Iron(II) and α-KG-Dependent Oxygenase. Inorg Chem 2020; 59:12218-12231. [PMID: 32822181 DOI: 10.1021/acs.inorgchem.0c01211] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Deacetoxycephalosporin C synthase (DAOCS) is a nonheme iron(II) and 2-oxoglutarate (α-KG)-dependent oxygenase that catalyzes the oxidative ring expansion of penicillin N (penN) to deacetoxycephalosporin C (DAOC). Earlier reported crystal structures of DAOCS indicated that the substrate penicillin binds at the same site of succinate, leading to the proposal of the unusual "ping-pong" mechanism. However, more recent data provided evidence of the formation of ternary DAOCS·α-KG·penN complex, and thus DAOCS should follow the usual consensus mechanism of α-KG-dependent nonheme iron(II) oxygenases. Nevertheless, how DAOCS catalyzes the ring expansion is unknown. In this paper, on the basis of the crystal structure, we constructed two reactant models and performed a series of combined quantum mechanics/molecular mechanics (QM/MM) calculations to illuminate the catalysis of DAOCS. The binding mode of substrate was found to be crucial in determining which hydrogen atom in two methyl groups is first abstracted and whether the second H-abstraction to be abstracted in the final desaturation step locates in a suitable orientation. The highly reactive FeIV-oxo species prefers to abstract a hydrogen atom from one of two methyl groups in penN to trigger the ring arrangement. After the H-abstraction, the generated methylene radical intermediate can easily initiate the ring arrangement. First, the C-S bond cleaves to generate a thiyl radical, which is in concert with the formation of the terminal C═C double bond; the newly generated thiyl radical then rapidly shifts to the more stable tertiary C atom to complete ring expansion. In the final step, the FeIII-OH species abstracts the second hydrogen to give the desaturated DAOC product. During the catalysis, no active site residue is directly involved in the chemistry, which implies that the other pocket residues except the coordinate ones with iron play a role only in anchoring the substrate.
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Affiliation(s)
- Yaru Liu
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China
| | - Junyou Shi
- College of Chemistry and Environmental Science, Qujing Normal University, Qujing, Yunnan 655011, China
| | - Yongjun Liu
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China
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15
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Evaluation of a concerted vs. sequential oxygen activation mechanism in α-ketoglutarate-dependent nonheme ferrous enzymes. Proc Natl Acad Sci U S A 2020; 117:5152-5159. [PMID: 32094179 DOI: 10.1073/pnas.1922484117] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Determining the requirements for efficient oxygen (O2) activation is key to understanding how enzymes maintain efficacy and mitigate unproductive, often detrimental reactivity. For the α-ketoglutarate (αKG)-dependent nonheme iron enzymes, both a concerted mechanism (both cofactor and substrate binding prior to reaction with O2) and a sequential mechanism (cofactor binding and reaction with O2 precede substrate binding) have been proposed. Deacetoxycephalosporin C synthase (DAOCS) is an αKG-dependent nonheme iron enzyme for which both of these mechanisms have been invoked to generate an intermediate that catalyzes oxidative ring expansion of penicillin substrates in cephalosporin biosynthesis. Spectroscopy shows that, in contrast to other αKG-dependent enzymes (which are six coordinate when only αKG is bound to the FeII), αKG binding to FeII-DAOCS results in ∼45% five-coordinate sites that selectively react with O2 relative to the remaining six-coordinate sites. However, this reaction produces an FeIII species that does not catalyze productive ring expansion. Alternatively, simultaneous αKG and substrate binding to FeII-DAOCS produces five-coordinate sites that rapidly react with O2 to form an FeIV=O intermediate that then reacts with substrate to produce cephalosporin product. These results demonstrate that the concerted mechanism is operative in DAOCS and by extension, other nonheme iron enzymes.
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16
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Kanazhevskaya LY, Alekseeva IV, Fedorova OS. A Single-Turnover Kinetic Study of DNA Demethylation Catalyzed by Fe(II)/α-Ketoglutarate-Dependent Dioxygenase AlkB. Molecules 2019; 24:molecules24244576. [PMID: 31847292 PMCID: PMC6943663 DOI: 10.3390/molecules24244576] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 11/26/2019] [Accepted: 12/11/2019] [Indexed: 01/31/2023] Open
Abstract
AlkB is a Fe(II)/α-ketoglutarate-dependent dioxygenase that repairs some alkylated bases of DNA and RNA in Escherichia coli. In the course of catalysis, oxidation of a co-substrate (α-ketoglutarate, αKG) leads to the formation of a highly reactive ‘oxyferryl’ enzyme-bound intermediate, Fe(IV) = O, ensuring hydroxylation of the alkyl nucleobase adducts. Previous studies have revealed that AlkB is a flexible protein and can adopt different conformations during interactions with cofactors and DNA. To assess the conformational dynamics of the enzyme in complex with single- or double-stranded DNA in real-time mode, we employed the stopped-flow fluorescence method. N1-Methyladenine (m1A) introduced into a sequence of 15-mer oligonucleotides was chosen as the specific damage. Single-turnover kinetics were monitored by means of intrinsic fluorescence of the protein’s Trp residues, fluorescent base analogue 2-aminopurine (2aPu), and a dye–quencher pair (FAM/BHQ1). For all the fluorescent labels, the fluorescent traces showed several phases of consistent conformational changes, which were assigned to specific steps of the enzymatic process. These data offer an overall picture of the structural dynamics of AlkB and DNA during their interaction.
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Affiliation(s)
| | | | - Olga S. Fedorova
- Correspondence: (L.Y.K.); (O.S.F.); Tel.: +7-(383)-3635175 (O.S.F.)
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17
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Rabe P, Kamps JJAG, Schofield CJ, Lohans CT. Roles of 2-oxoglutarate oxygenases and isopenicillin N synthase in β-lactam biosynthesis. Nat Prod Rep 2018; 35:735-756. [PMID: 29808887 PMCID: PMC6097109 DOI: 10.1039/c8np00002f] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Indexed: 01/01/2023]
Abstract
Covering: up to 2017 2-Oxoglutarate (2OG) dependent oxygenases and the homologous oxidase isopenicillin N synthase (IPNS) play crucial roles in the biosynthesis of β-lactam ring containing natural products. IPNS catalyses formation of the bicyclic penicillin nucleus from a tripeptide. 2OG oxygenases catalyse reactions that diversify the chemistry of β-lactams formed by both IPNS and non-oxidative enzymes. Reactions catalysed by the 2OG oxygenases of β-lactam biosynthesis not only involve their typical hydroxylation reactions, but also desaturation, epimerisation, rearrangement, and ring-forming reactions. Some of the enzymes involved in β-lactam biosynthesis exhibit remarkable substrate and product selectivities. We review the roles of 2OG oxygenases and IPNS in β-lactam biosynthesis, highlighting opportunities for application of knowledge of their roles, structures, and mechanisms.
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Affiliation(s)
- Patrick Rabe
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, UK.
| | - Jos J A G Kamps
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, UK.
| | - Christopher J Schofield
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, UK.
| | - Christopher T Lohans
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, UK.
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18
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Developing a colorimetric assay for Fe(II)/2-oxoglutarate-dependent dioxygenase. Anal Biochem 2018; 548:109-114. [DOI: 10.1016/j.ab.2018.02.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 02/09/2018] [Accepted: 02/12/2018] [Indexed: 01/27/2023]
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19
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Abstract
2-Oxoglutarate (2OG)-dependent oxygenases (2OGXs) catalyze a remarkably diverse range of oxidative reactions. In animals, these comprise hydroxylations and N-demethylations proceeding via hydroxylation; in plants and microbes, they catalyze a wider range including ring formations, rearrangements, desaturations, and halogenations. The catalytic flexibility of 2OGXs is reflected in their biological functions. After pioneering work identified the roles of 2OGXs in collagen biosynthesis, research revealed they also function in plant and animal development, transcriptional regulation, nucleic acid modification/repair, fatty acid metabolism, and secondary metabolite biosynthesis, including of medicinally important antibiotics. In plants, 2OGXs are important agrochemical targets and catalyze herbicide degradation. Human 2OGXs, particularly those regulating transcription, are current therapeutic targets for anemia and cancer. Here, we give an overview of the biochemistry of 2OGXs, providing examples linking to biological function, and outline how knowledge of their enzymology is being exploited in medicine, agrochemistry, and biocatalysis.
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Affiliation(s)
- Md Saiful Islam
- The Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom;
| | - Thomas M Leissing
- The Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom;
| | - Rasheduzzaman Chowdhury
- The Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom;
| | - Richard J Hopkinson
- The Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom; .,Current affiliation for Richard J. Hopkinson: Leicester Institute of Structural and Chemical Biology and Department of Chemistry, University of Leicester, Leicester LE1 7RH, United Kingdom;
| | - Christopher J Schofield
- The Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom;
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20
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Nakamura H, Matsuda Y, Abe I. Unique chemistry of non-heme iron enzymes in fungal biosynthetic pathways. Nat Prod Rep 2018. [DOI: 10.1039/c7np00055c] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Reactions by non-heme iron enzymes in structurally intriguing fungal natural products pathways are summarized and discussed.
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Affiliation(s)
- Hitomi Nakamura
- Graduate School of Pharmaceutical Sciences
- The University of Tokyo
- Tokyo
- Japan
| | - Yudai Matsuda
- Graduate School of Pharmaceutical Sciences
- The University of Tokyo
- Tokyo
- Japan
- Department of Chemistry
| | - Ikuro Abe
- Graduate School of Pharmaceutical Sciences
- The University of Tokyo
- Tokyo
- Japan
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21
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Amaya JA, Rutland CD, Leschinsky N, Makris TM. A Distal Loop Controls Product Release and Chemo- and Regioselectivity in Cytochrome P450 Decarboxylases. Biochemistry 2017; 57:344-353. [PMID: 29227633 DOI: 10.1021/acs.biochem.7b01065] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Cytochrome P450 OleT utilizes hydrogen peroxide (H2O2) to catalyze the decarboxylation or hydroxylation of fatty acid (FA) substrates. Both reactions are initiated through the abstraction of a substrate hydrogen atom by the high-valent iron-oxo intermediate known as Compound I. Here, we specifically probe the influence of substrate coordination on OleT reaction partitioning through the combined use of fluorescent and electron paramagnetic resonance (EPR)-active FA probes and mutagenesis of a structurally disordered F-G loop that is distal from the heme-iron active site. Both probes are efficiently metabolized by OleT and efficiently trigger the formation of Compound I. Transient fluorescence and EPR reveal a slow product release step, mediated by the F-G loop, that limits OleT turnover. A single-amino acid change or excision of the loop reveals that this region establishes critical interactions to anchor FA substrates in place. The stabilization afforded by the F-G loop is essential for regulating regiospecific C-H abstraction and allowing for efficient decarboxylation to occur. These results highlight a regulatory strategy whereby the fate of activated oxygen species can be controlled at distances far removed from the site of chemistry.
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Affiliation(s)
- José A Amaya
- Department of Chemistry and Biochemistry, University of South Carolina , Columbia, South Carolina 29208, United States
| | - Cooper D Rutland
- Department of Chemistry and Biochemistry, University of South Carolina , Columbia, South Carolina 29208, United States
| | - Nicholas Leschinsky
- Department of Chemistry and Biochemistry, University of South Carolina , Columbia, South Carolina 29208, United States
| | - Thomas M Makris
- Department of Chemistry and Biochemistry, University of South Carolina , Columbia, South Carolina 29208, United States
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22
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Rigid scaffolds for the design of molecular catalysts and biomimetic active sites: A case study of anthracene-based ligands for modeling mono-iron hydrogenase (Hmd). Coord Chem Rev 2017. [DOI: 10.1016/j.ccr.2017.09.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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23
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Dunbar KL, Scharf DH, Litomska A, Hertweck C. Enzymatic Carbon-Sulfur Bond Formation in Natural Product Biosynthesis. Chem Rev 2017; 117:5521-5577. [PMID: 28418240 DOI: 10.1021/acs.chemrev.6b00697] [Citation(s) in RCA: 337] [Impact Index Per Article: 48.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Sulfur plays a critical role for the development and maintenance of life on earth, which is reflected by the wealth of primary metabolites, macromolecules, and cofactors bearing this element. Whereas a large body of knowledge has existed for sulfur trafficking in primary metabolism, the secondary metabolism involving sulfur has long been neglected. Yet, diverse sulfur functionalities have a major impact on the biological activities of natural products. Recent research at the genetic, biochemical, and chemical levels has unearthed a broad range of enzymes, sulfur shuttles, and chemical mechanisms for generating carbon-sulfur bonds. This Review will give the first systematic overview on enzymes catalyzing the formation of organosulfur natural products.
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Affiliation(s)
- Kyle L Dunbar
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI) , Beutenbergstrasse 11a, 07745 Jena, Germany
| | - Daniel H Scharf
- Life Sciences Institute, University of Michigan , 210 Washtenaw Avenue, Ann Arbor, Michigan 48109-2216, United States
| | - Agnieszka Litomska
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI) , Beutenbergstrasse 11a, 07745 Jena, Germany
| | - Christian Hertweck
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI) , Beutenbergstrasse 11a, 07745 Jena, Germany.,Friedrich Schiller University , 07743 Jena, Germany
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24
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Kal S, Que L. Dioxygen activation by nonheme iron enzymes with the 2-His-1-carboxylate facial triad that generate high-valent oxoiron oxidants. J Biol Inorg Chem 2017; 22:339-365. [PMID: 28074299 DOI: 10.1007/s00775-016-1431-2] [Citation(s) in RCA: 154] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 12/13/2016] [Indexed: 11/24/2022]
Abstract
The 2-His-1-carboxylate facial triad is a widely used scaffold to bind the iron center in mononuclear nonheme iron enzymes for activating dioxygen in a variety of oxidative transformations of metabolic significance. Since the 1990s, over a hundred different iron enzymes have been identified to use this platform. This structural motif consists of two histidines and the side chain carboxylate of an aspartate or a glutamate arranged in a facial array that binds iron(II) at the active site. This triad occupies one face of an iron-centered octahedron and makes the opposite face available for the coordination of O2 and, in many cases, substrate, allowing the tailoring of the iron-dioxygen chemistry to carry out a plethora of diverse reactions. Activated dioxygen-derived species involved in the enzyme mechanisms include iron(III)-superoxo, iron(III)-peroxo, and high-valent iron(IV)-oxo intermediates. In this article, we highlight the major crystallographic, spectroscopic, and mechanistic advances of the past 20 years that have significantly enhanced our understanding of the mechanisms of O2 activation and the key roles played by iron-based oxidants.
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Affiliation(s)
- Subhasree Kal
- Department of Chemistry, Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Lawrence Que
- Department of Chemistry, Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, MN, 55455, USA.
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25
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Abstract
The non-heme Fe enzymes are ubiquitous in nature and perform a wide range of functions involving O2 activation. These had been difficult to study relative to heme enzymes; however, spectroscopic methods that provide significant insight into the correlation of structure with function have now been developed. This Current Topics article summarizes both the molecular mechanism these enzymes use to control O2 activation in the presence of cosubstrates and the oxygen intermediates these reactions generate. Three types of O2 activation are observed. First, non-heme reactivity is shown to be different from heme chemistry where a low-spin FeIII-OOH non-heme intermediate directly reacts with substrate. Also, two subclasses of non-heme Fe enzymes generate high-spin FeIV═O intermediates that provide both σ and π frontier molecular orbitals that can control selectivity. Finally, for several subclasses of non-heme Fe enzymes, binding of the substrate to the FeII site leads to the one-electron reductive activation of O2 to an FeIII-superoxide capable of H atom abstraction and electrophilic attack.
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Affiliation(s)
- Edward I Solomon
- Department of Chemistry, Stanford University , Stanford, California 94305, United States.,SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States
| | - Serra Goudarzi
- Department of Chemistry, Stanford University , Stanford, California 94305, United States
| | - Kyle D Sutherlin
- Department of Chemistry, Stanford University , Stanford, California 94305, United States
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26
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Fan K, Lin B, Tao Y, Yang K. Engineering deacetoxycephalosporin C synthase as a catalyst for the bioconversion of penicillins. J Ind Microbiol Biotechnol 2016; 44:705-710. [PMID: 27826726 DOI: 10.1007/s10295-016-1857-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 10/30/2016] [Indexed: 11/27/2022]
Abstract
7-aminodeacetoxycephalosporanic acid (7-ADCA) is a key intermediate of many clinically useful semisynthetic cephalosporins that were traditionally prepared by processes involving chemical ring expansion of penicillin G. Bioconversion of penicillins to cephalosporins using deacetoxycephalosporin C synthase (DAOCS) is an alternative and environmentally friendly process for 7-ADCA production. Arnold Demain and co-workers pioneered such a process. Later, protein engineering efforts to improve the substrate specificity and catalytic efficiency of DAOCS for penicillins have been made by many groups, and a whole cell process using Escherichia coli for bioconversion of penicillins has been developed.
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Affiliation(s)
- Keqiang Fan
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No. 1 West Beichen Road, Beijing, 100101, People's Republic of China
| | - Baixue Lin
- ASCR Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, People's Republic of China
| | - Yong Tao
- ASCR Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, People's Republic of China
| | - Keqian Yang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No. 1 West Beichen Road, Beijing, 100101, People's Republic of China.
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27
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Abstract
Mononuclear non-heme Fe(II)- and 2-oxoglutarate (2OG)-dependent oxygenases comprise a large family of enzymes that utilize an Fe(IV)-oxo intermediate to initiate diverse oxidative transformations with important biological roles. Here, four of the major types of Fe(II)/2OG-dependent reactions are detailed: hydroxylation, halogenation, ring formation, and desaturation. In addition, an atypical epimerization reaction is described. Studies identifying several key intermediates in catalysis are concisely summarized, and the proposed mechanisms are explained. In addition, a variety of other transformations catalyzed by selected family members are briefly described to further highlight the chemical versatility of these enzymes.
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Affiliation(s)
- Salette Martinez
- Departments of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan 48824
| | - Robert P Hausinger
- Departments of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan 48824; Departments of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824.
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Tarhonskaya H, Hardy AP, Howe EA, Loik ND, Kramer HB, McCullagh JSO, Schofield CJ, Flashman E. Kinetic Investigations of the Role of Factor Inhibiting Hypoxia-inducible Factor (FIH) as an Oxygen Sensor. J Biol Chem 2015; 290:19726-42. [PMID: 26112411 PMCID: PMC4528135 DOI: 10.1074/jbc.m115.653014] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2015] [Revised: 06/24/2015] [Indexed: 01/23/2023] Open
Abstract
The hypoxia-inducible factor (HIF) hydroxylases regulate hypoxia sensing in animals. In humans, they comprise three prolyl hydroxylases (PHD1-3 or EGLN1-3) and factor inhibiting HIF (FIH). FIH is an asparaginyl hydroxylase catalyzing post-translational modification of HIF-α, resulting in reduction of HIF-mediated transcription. Like the PHDs, FIH is proposed to have a hypoxia-sensing role in cells, enabling responses to changes in cellular O2 availability. PHD2, the most important human PHD isoform, is proposed to be biochemically/kinetically suited as a hypoxia sensor due to its relatively high sensitivity to changes in O2 concentration and slow reaction with O2. To ascertain whether these parameters are conserved among the HIF hydroxylases, we compared the reactions of FIH and PHD2 with O2. Consistent with previous reports, we found lower Km(app)(O2) values for FIH than for PHD2 with all HIF-derived substrates. Under pre-steady-state conditions, the O2-initiated FIH reaction is significantly faster than that of PHD2. We then investigated the kinetics with respect to O2 of the FIH reaction with ankyrin repeat domain (ARD) substrates. FIH has lower Km(app)(O2) values for the tested ARDs than HIF-α substrates, and pre-steady-state O2-initiated reactions were faster with ARDs than with HIF-α substrates. The results correlate with cellular studies showing that FIH is active at lower O2 concentrations than the PHDs and suggest that competition between HIF-α and ARDs for FIH is likely to be biologically relevant, particularly in hypoxic conditions. The overall results are consistent with the proposal that the kinetic properties of individual oxygenases reflect their biological capacity to act as hypoxia sensors.
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Affiliation(s)
- Hanna Tarhonskaya
- From the Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom and
| | - Adam P Hardy
- From the Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom and
| | - Emily A Howe
- From the Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom and
| | - Nikita D Loik
- From the Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom and
| | - Holger B Kramer
- the OXION Proteomics Facility, Department of Physiology, Anatomy, and Genetics, University of Oxford, South Parks Road, Oxford OX1 3QX, United Kingdom
| | - James S O McCullagh
- From the Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom and
| | - Christopher J Schofield
- From the Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom and
| | - Emily Flashman
- From the Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom and
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29
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Reconstitution of TCA cycle with DAOCS to engineer Escherichia coli into an efficient whole cell catalyst of penicillin G. Proc Natl Acad Sci U S A 2015. [PMID: 26216972 DOI: 10.1073/pnas.1502866112] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Many medically useful semisynthetic cephalosporins are derived from 7-aminodeacetoxycephalosporanic acid (7-ADCA), which has been traditionally made by the polluting chemical method. Here, a whole-cell biocatalytic process based on an engineered Escherichia coli strain expressing 2-oxoglutarate-dependent deacetoxycephalosporin C synthase (DAOCS) for converting penicillin G to G-7-ADCA is developed. The major engineering strategy is to reconstitute the tricarboxylic acid (TCA) cycle of E. coli to force the metabolic flux to go through DAOCS catalyzed reaction for 2-oxoglutarate to succinate conversion. Then the glyoxylate bypass was disrupted to eliminate metabolic flux that may circumvent the reconstituted TCA cycle. Additional engineering steps were taken to reduce the degradation of penicillin G and G-7-ADCA in the bioconversion process. These steps include engineering strategies to reduce acetate accumulation in the biocatalytic process and to knock out a host β-lactamase involved in the degradation of penicillin G and G-7-ADCA. By combining these manipulations in an engineered strain, the yield of G-7-ADCA was increased from 2.50 ± 0.79 mM (0.89 ± 0.28 g/L, 0.07 ± 0.02 g/gDCW) to 29.01 ± 1.27 mM (10.31 ± 0.46 g/L, 0.77 ± 0.03 g/gDCW) with a conversion rate of 29.01 mol%, representing an 11-fold increase compared with the starting strain (2.50 mol%).
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30
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Andersson I, Valegård K. 2-Oxoglutarate-Dependent Oxygenases of Cephalosporin Synthesis. 2-OXOGLUTARATE-DEPENDENT OXYGENASES 2015. [DOI: 10.1039/9781782621959-00385] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Central steps in the biosynthetic pathways of some of the most commonly used antibiotics, the cephalosporins, are catalysed by 2-oxoglutarate (2OG)-dependent oxygenases. Deacetoxycephalosporin C synthase (DAOCS) catalyses the 2OG-dependent oxidative expansion of the five-membered thiazolidine ring of the penicillin nucleus into the six-membered dihydrothiazine ring of the cephalosporin nucleus. DAOCS uses dioxygen to create a reactive iron–oxygen intermediate from ferrous ion to drive the reaction. In prokaryotic cephalosporin producers, the cephalosporin product, DAOC, is hydroxylated at the 3′-position to form deacetylcephalosporin C (DAC) as catalysed by a second 2OG-dependent enzyme, DAC synthase (DACS). In eukaryotic cephalosporin producers, the reaction is catalysed by a bifunctional enzyme, DAOC/DACS, that catalyses both the ring expansion and the 3′-hydroxylation reactions. The prokaryotic and eukaryotic enzymes are closely related to DAOCS by sequence, suggesting these enzymes may have evolved by gene duplication. Cephamycin C-producing microorganisms use two enzymes, encoded by the genes cmcI/J, to convert cephalosporins to their 7α-methoxy derivatives that are less vulnerable to β-lactam hydrolysing enzymes. The methoxylation reaction is dependent on Fe(ii), 2OG and S-adenosylmethionine, suggesting the involvement of another 2OG-dependent oxygenase. Herein, structural and mechanistic features are summarized for these 2OG enzymes that utilize this common and flexible mode of dioxygen activation.
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Affiliation(s)
- Inger Andersson
- Department of Cell and Molecular Biology, Uppsala University Box 596, S-751 24 Uppsala Sweden
| | - Karin Valegård
- Department of Cell and Molecular Biology, Uppsala University Box 596, S-751 24 Uppsala Sweden
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31
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Fang X, Di YT, Zhang Y, Xu ZP, Lu Y, Chen QQ, Zheng QT, Hao XJ. Unprecedented Quassinoids with Promising Biological Activity fromHarrisonia perforata. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201412126] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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32
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Fang X, Di YT, Zhang Y, Xu ZP, Lu Y, Chen QQ, Zheng QT, Hao XJ. Unprecedented Quassinoids with Promising Biological Activity fromHarrisonia perforata. Angew Chem Int Ed Engl 2015; 54:5592-5. [DOI: 10.1002/anie.201412126] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 02/28/2015] [Indexed: 11/10/2022]
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33
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Hangasky JA, Gandhi H, Valliere MA, Ostrom NE, Knapp MJ. The rate-limiting step of O2 activation in the α-ketoglutarate oxygenase factor inhibiting hypoxia inducible factor. Biochemistry 2014; 53:8077-84. [PMID: 25423620 PMCID: PMC4283935 DOI: 10.1021/bi501246v] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
![]()
Factor
inhibiting HIF (FIH) is a cellular O2-sensing enzyme, which
hydroxylates the hypoxia inducible factor-1α. Previously reported
inverse solvent kinetic isotope effects indicated that FIH limits
its overall turnover through an O2 activation step (HangaskyJ. A., SabanE.,
and KnappM. J. (2013) 52, 1594−160223351038). Here we characterize the rate-limiting step for O2 activation by FIH using a suite of mechanistic probes on
the second order rate constant kcat/KM(O2). Steady-state kinetics showed
that the rate constant for O2 activation was slow (kcat/KM(O2)app = 3500 M–1 s–1) compared with other non-heme iron oxygenases,
and solvent viscosity assays further excluded diffusional encounter
with O2 from being rate limiting on kcat/KM(O2). Competitive
oxygen-18 kinetic isotope effect measurements (18kcat/KM(O2) = 1.0114(5)) indicated that the transition state for O2 activation resembled a cyclic peroxohemiketal, which precedes the
formation of the ferryl intermediate observed in related enzymes.
We interpret this data to indicate that FIH limits its overall activity
at the point of the nucleophilic attack of Fe-bound O2— on the C-2 carbon of αKG. Overall, these results
show that FIH follows the consensus mechanism for αKG oxygenases,
suggesting that FIH may be an ideal enzyme to directly access steps
involved in O2 activation among the broad family of αKG
oxygenases.
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Affiliation(s)
- John A Hangasky
- Department of Chemistry, University of Massachusetts , Amherst, Massachusetts 01003, United States
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34
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Tarhonskaya H, Chowdhury R, Leung IKH, Loik ND, McCullagh JSO, Claridge TDW, Schofield CJ, Flashman E. Investigating the contribution of the active site environment to the slow reaction of hypoxia-inducible factor prolyl hydroxylase domain 2 with oxygen. Biochem J 2014; 463:363-72. [PMID: 25120187 DOI: 10.1042/bj20140779] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2024]
Abstract
The prolyl hydroxylase domain proteins (PHDs) catalyse the post-translational hydroxylation of the hypoxia-inducible factor (HIF), a modification that regulates the hypoxic response in humans. The PHDs are Fe(II)/2-oxoglutarate (2OG) oxygenases; their catalysis is proposed to provide a link between cellular HIF levels and changes in O2 availability. Transient kinetic studies have shown that purified PHD2 reacts slowly with O2 compared with some other studied 2OG oxygenases, a property which may be related to its hypoxia-sensing role. PHD2 forms a stable complex with Fe(II) and 2OG; crystallographic and kinetic analyses indicate that an Fe(II)-co-ordinated water molecule, which must be displaced before O2 binding, is relatively stable in the active site of PHD2. We used active site substitutions to investigate whether these properties are related to the slow reaction of PHD2 with O2. While disruption of 2OG binding in a R383K variant did not accelerate O2 activation, we found that substitution of the Fe(II)-binding aspartate for a glutamate residue (D315E) manifested significantly reduced Fe(II) binding, yet maintained catalytic activity with a 5-fold faster reaction with O2. The results inform on how the precise active site environment of oxygenases can affect rates of O2 activation and provide insights into limiting steps in PHD catalysis.
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Affiliation(s)
- Hanna Tarhonskaya
- *Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, U.K
| | - Rasheduzzaman Chowdhury
- *Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, U.K
| | - Ivanhoe K H Leung
- *Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, U.K
| | - Nikita D Loik
- *Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, U.K
| | - James S O McCullagh
- *Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, U.K
| | - Timothy D W Claridge
- *Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, U.K
| | - Christopher J Schofield
- *Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, U.K
| | - Emily Flashman
- *Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, U.K
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Cochrane RVK, Vederas JC. Highly selective but multifunctional oxygenases in secondary metabolism. Acc Chem Res 2014; 47:3148-61. [PMID: 25250512 DOI: 10.1021/ar500242c] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Biosynthesis of bioactive natural products frequently features oxidation at multiple sites. Starting from a relatively reduced chemical scaffold that is assembled by controlled polymerization of small precursors, for example, acetate or amino acids, a diverse range of redox reactions can generate very complex and highly oxygenated structures. Their formation often involves C-H activation reactions catalyzed by oxygenase enzymes, either monooxygenases or dioxygenases. The former category includes the cytochrome P450s and flavin-dependent oxygenases, whereas examples of the latter are the non-heme iron α-ketoglutarate-dependent oxygenases. Oxygenases can catalyze a plethora of reactions ranging from hydroxylations and epoxidations to dehydrogenations, cyclizations, and rearrangements. The specific transformations are usually possible only with the use of these enzymatic catalysts. Aside from the ability of oxygenases to specifically oxidize unactivated carbon skeletons, some have recently been demonstrated to possess a fascinating ability to catalyze multiple reactions in a highly ordered fashion at different sites starting with a single substrate molecule. In the past, oxygenases associated with secondary metabolite pathways were considered to be highly regio-, stereo-, and substrate specific, with one oxidizing enzyme encoded in the gene cluster corresponding to one oxidation location in the natural product itself. However, it is becoming progressively clear that this "one oxygenase, one oxidation site" relationship is not necessarily a valid assumption. Multifunctional oxidases are known to occur in higher plants, fungi, and bacteria. Natural product gene clusters that contain multifunctional oxidase enzymes are responsible for production of lovastatin (a cholesterol-lowering agent and precursor to simvastatin), scopolamine (an anticholinergic drug), and cytochalasin E (an angiogenesis inhibitor), among many others. As opposed to simply being substrate promiscuous, these enzymes show very high substrate specificity and catalyze several oxidative reactions in a single pathway, with each oxidation being a prerequisite for the next. The basis for their specificity and highly ordered sequence is not yet well understood. In the lovastatin pathway, LovA is a cytochrome P450 that introduces a double bond and a hydroxyl group. H6H is an α-ketoglutarate-dependent oxygenase that hydroxylates (-)-atropine and then closes the newly introduced oxygen onto a neighboring methylene to generate the epoxide of scopolamine. CcsB is a flavin-dependent Baeyer-Villigerase that converts a ketone to a carbonate by double oxidation, a reaction not possible without enzymes. Recent crystallographic studies of other multifunctional oxygenases, such as AurH, a cytochrome P450 from Streptomyces thioluteus involved in aureothin biosynthesis, have indicated a steric switch mechanism. After the initial hydroxylation reaction catalyzed by AurH, the enzyme is thought to undergo a substrate-induced conformational change. In this Account, advances in our knowledge of these fascinating multifunctional enzymes and their potential will be explored.
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Affiliation(s)
| | - John C. Vederas
- Department
of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2 Canada
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36
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Farrow SC, Facchini PJ. Functional diversity of 2-oxoglutarate/Fe(II)-dependent dioxygenases in plant metabolism. FRONTIERS IN PLANT SCIENCE 2014; 5:524. [PMID: 25346740 PMCID: PMC4191161 DOI: 10.3389/fpls.2014.00524] [Citation(s) in RCA: 111] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 09/16/2014] [Indexed: 05/18/2023]
Abstract
Oxidative enzymes catalyze many different reactions in plant metabolism. Among this suite of enzymes are the 2-oxoglutarate/Fe(II)-dependent dioxygenases (2-ODDs). Cytochromes P450 (CYPs) as often considered the most versatile oxidative enzymes in nature, but the diversity and complexity of reactions catalyzed by 2-ODDs is superior to the CYPs. The list of oxidative reactions catalyzed by 2-ODDs includes hydroxylations, demethylations, desaturations, ring closure, ring cleavage, epimerization, rearrangement, halogenation, and demethylenation. Furthermore, recent work, including the discovery of 2-ODDs involved in epigenetic regulation, and others catalyzing several characteristic steps in specialized metabolic pathways, support the argument that 2-ODDs are among the most versatile and important oxidizing biological catalysts. In this review, we survey and summarize the pertinent literature with a focus on several key reactions catalyzed by 2-ODDs, and discuss the significance and impact of these enzymes in plant metabolism.
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Affiliation(s)
| | - Peter J. Facchini
- Department of Biological Sciences, University of CalgaryCalgary, AB, Canada
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