1
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Johnson SB, Li H, Valentino H, Sobrado P. Mechanism of Nitrone Formation by a Flavin-Dependent Monooxygenase. Biochemistry 2024. [PMID: 38779817 DOI: 10.1021/acs.biochem.3c00656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2024]
Abstract
OxaD is a flavin-dependent monooxygenase (FMO) responsible for catalyzing the oxidation of an indole nitrogen atom, resulting in the formation of a nitrone. Nitrones serve as versatile intermediates in complex syntheses, including challenging reactions like cycloadditions. Traditional organic synthesis methods often yield limited results and involve environmentally harmful chemicals. Therefore, the enzymatic synthesis of nitrone-containing compounds holds promise for more sustainable industrial processes. In this study, we explored the catalytic mechanism of OxaD using a combination of steady-state and rapid-reaction kinetics, site-directed mutagenesis, spectroscopy, and structural modeling. Our investigations showed that OxaD catalyzes two oxidations of the indole nitrogen of roquefortine C, ultimately yielding roquefortine L. The reductive-half reaction analysis indicated that OxaD rapidly undergoes reduction and follows a "cautious" flavin reduction mechanism by requiring substrate binding before reduction can take place. This characteristic places OxaD in class A of the FMO family, a classification supported by a structural model featuring a single Rossmann nucleotide binding domain and a glutathione reductase fold. Furthermore, our spectroscopic analysis unveiled both enzyme-substrate and enzyme-intermediate complexes. Our analysis of the oxidative-half reaction suggests that the flavin dehydration step is the slow step in the catalytic cycle. Finally, through mutagenesis of the conserved D63 residue, we demonstrated its role in flavin motion and product oxygenation. Based on our findings, we propose a catalytic mechanism for OxaD and provide insights into the active site architecture within class A FMOs.
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Affiliation(s)
- Sydney B Johnson
- Department of Biochemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Hao Li
- Department of Biochemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Hannah Valentino
- Department of Biochemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Pablo Sobrado
- Department of Biochemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
- Center of Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
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2
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Launay R, Chobert SC, Abby SS, Pierrel F, André I, Esque J. Structural Reconstruction of E. coli Ubi Metabolon Using an AlphaFold2-Based Computational Framework. J Chem Inf Model 2024. [PMID: 38710096 DOI: 10.1021/acs.jcim.4c00304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Ubiquinone (UQ) is a redox polyisoprenoid lipid found in the membranes of bacteria and eukaryotes that has important roles, notably one in respiratory metabolism, which sustains cellular bioenergetics. In Escherichia coli, several steps of the UQ biosynthesis take place in the cytosol. To perform these reactions, a supramolecular assembly called Ubi metabolon is involved. This latter is composed of seven proteins (UbiE, UbiG, UbiF, UbiH, UbiI, UbiJ, and UbiK), and its structural organization is unknown as well as its protein stoichiometry. In this study, a computational framework has been designed to predict the structure of this macromolecular assembly. In several successive steps, we explored the possible protein interactions as well as the protein stoichiometry, to finally obtain a structural organization of the complex. The use of AlphaFold2-based methods combined with evolutionary information enabled us to predict several models whose quality and confidence were further analyzed using different metrics and scores. Our work led to the identification of a "core assembly" that will guide functional and structural characterization of the Ubi metabolon.
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Affiliation(s)
- Romain Launay
- Toulouse Biotechnology Institute, TBI, Université de Toulouse, CNRS, INRAE, INSA, 31077 Toulouse, France
| | - Sophie-Carole Chobert
- Univ. Grenoble Alpes, CNRS, UMR 5525, VetAgro Sup, Grenoble INP, TIMC, 38000 Grenoble, France
| | - Sophie S Abby
- Univ. Grenoble Alpes, CNRS, UMR 5525, VetAgro Sup, Grenoble INP, TIMC, 38000 Grenoble, France
| | - Fabien Pierrel
- Univ. Grenoble Alpes, CNRS, UMR 5525, VetAgro Sup, Grenoble INP, TIMC, 38000 Grenoble, France
| | - Isabelle André
- Toulouse Biotechnology Institute, TBI, Université de Toulouse, CNRS, INRAE, INSA, 31077 Toulouse, France
| | - Jérémy Esque
- Toulouse Biotechnology Institute, TBI, Université de Toulouse, CNRS, INRAE, INSA, 31077 Toulouse, France
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3
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Pierdominici‐Sottile G, Palma J, Ferrelli ML, Sobrado P. The dynamics of the flavin, NADPH, and active site loops determine the mechanism of activation of class B flavin-dependent monooxygenases. Protein Sci 2024; 33:e4935. [PMID: 38501462 PMCID: PMC10962481 DOI: 10.1002/pro.4935] [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: 10/11/2023] [Revised: 02/02/2024] [Accepted: 02/06/2024] [Indexed: 03/20/2024]
Abstract
Flavin-dependent monooxygenases (FMOs) constitute a diverse enzyme family that catalyzes crucial hydroxylation, epoxidation, and Baeyer-Villiger reactions across various metabolic pathways in all domains of life. Due to the intricate nature of this enzyme family's mechanisms, some aspects of their functioning remain unknown. Here, we present the results of molecular dynamics computations, supplemented by a bioinformatics analysis, that clarify the early stages of their catalytic cycle. We have elucidated the intricate binding mechanism of NADPH and L-Orn to a class B monooxygenase, the ornithine hydroxylase fromAspergillus $$ Aspergillus $$ fumigatus $$ fumigatus $$ known as SidA. Our investigation involved a comprehensive characterization of the conformational changes associated with the FAD (Flavin Adenine Dinucleotide) cofactor, transitioning from the out to the in position. Furthermore, we explored the rotational dynamics of the nicotinamide ring of NADPH, shedding light on its role in facilitating FAD reduction, supported by experimental evidence. Finally, we also analyzed the extent of conservation of two Tyr-loops that play critical roles in the process.
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Affiliation(s)
- Gustavo Pierdominici‐Sottile
- Departamento de Ciencia y TecnologíaUniversidad Nacional de QuilmesBernalArgentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)CABAArgentina
| | - Juliana Palma
- Departamento de Ciencia y TecnologíaUniversidad Nacional de QuilmesBernalArgentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)CABAArgentina
| | - María Leticia Ferrelli
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)CABAArgentina
- Instituto de Biotecnología y Biología Molecular (IBBM, UNLP‐CONICET), Facultad de Ciencias ExactasUniversidad Nacional de La PlataLa PlataBuenos AiresArgentina
| | - Pablo Sobrado
- Department of BiochemistryVirginia TechBlacksburgVirginiaUSA
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4
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Turlington ZR, Vaz Ferreira de Macedo S, Perry K, Belsky SL, Faust JA, Snider MJ, Hicks KA. Ligand bound structure of a 6-hydroxynicotinic acid 3-monooxygenase provides mechanistic insights. Arch Biochem Biophys 2024; 752:109859. [PMID: 38104959 DOI: 10.1016/j.abb.2023.109859] [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: 10/31/2023] [Revised: 12/08/2023] [Accepted: 12/11/2023] [Indexed: 12/19/2023]
Abstract
6-Hydroxynicotinic acid 3-monooxygenase (NicC) is a bacterial enzyme involved in the degradation of nicotinic acid. This enzyme is a Class A flavin-dependent monooxygenase that catalyzes a unique decarboxylative hydroxylation. The unliganded structure of this enzyme has previously been reported and studied using steady- and transient-state kinetics to support a comprehensive kinetic mechanism. Here we report the crystal structure of the H47Q NicC variant in both a ligand-bound (solved to 2.17 Å resolution) and unliganded (1.51 Å resolution) form. Interestingly, in the liganded form, H47Q NicC is bound to 2-mercaptopyridine (2-MP), a contaminant present in the commercial stock of 6-mercaptopyridine-3-carboxylic acid(6-MNA), a substrate analogue. 2-MP binds weakly to H47Q NicC and is not a substrate for the enzyme. Based on kinetic and thermodynamic characterization, we have fortuitously captured a catalytically inactive H47Q NicC•2-MP complex in our crystal structure. This complex reveals interesting mechanistic details about the reaction catalyzed by 6-hydroxynicotinic acid 3-monooxygenase.
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Affiliation(s)
- Zachary R Turlington
- Department of Chemistry, State University of New York at Cortland, Cortland, NY, 13045, United States
| | | | - Kay Perry
- NE-CAT and Department of Chemistry and Chemical Biology, Cornell University, Argonne National Laboratory, Argonne, IL, United States
| | - Sam L Belsky
- Department of Chemistry, The College of Wooster, Wooster, OH, 44691, United States
| | - Jennifer A Faust
- Department of Chemistry, The College of Wooster, Wooster, OH, 44691, United States
| | - Mark J Snider
- Department of Chemistry, The College of Wooster, Wooster, OH, 44691, United States
| | - Katherine A Hicks
- Department of Chemistry, State University of New York at Cortland, Cortland, NY, 13045, United States.
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Katsuki N, Fukushima R, Doi Y, Masuo S, Arakawa T, Yamada C, Fushinobu S, Takaya N. Protocatechuate hydroxylase is a novel group A flavoprotein monooxygenase with a unique substrate recognition mechanism. J Biol Chem 2024; 300:105508. [PMID: 38029967 PMCID: PMC10770758 DOI: 10.1016/j.jbc.2023.105508] [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: 10/11/2023] [Revised: 11/20/2023] [Accepted: 11/22/2023] [Indexed: 12/01/2023] Open
Abstract
Para-hydroxybenzoate hydroxylase (PHBH) is a group A flavoprotein monooxygenase that hydroxylates p-hydroxybenzoate to protocatechuate (PCA). Despite intensive studies of Pseudomonas aeruginosa p-hydroxybenzoate hydroxylase (PaPobA), the catalytic reactions of extremely diverse putative PHBH isozymes remain unresolved. We analyzed the phylogenetic relationships of known and predicted PHBHs and identified eight divergent clades. Clade F contains a protein that lacks the critical amino acid residues required for PaPobA to generate PHBH activity. Among proteins in this clade, Xylophilus ampelinus PobA (XaPobA) preferred PCA as a substrate and is the first known natural PCA 5-hydroxylase (PCAH). Crystal structures and kinetic properties revealed similar mechanisms of substrate carboxy group recognition between XaPobA and PaPobA. The unique Ile75, Met72, Val199, Trp201, and Phe385 residues of XaPobA form the bottom of a hydrophobic cavity with a shape that complements the 3-and 4-hydroxy groups of PCA and its binding site configuration. An interaction between the δ-sulfur atom of Met210 and the aromatic ring of PCA is likely to stabilize XaPobA-PCA complexes. The 4-hydroxy group of PCA forms a hydrogen bond with the main chain carbonyl of Thr294. These modes of binding constitute a novel substrate recognition mechanism that PaPobA lacks. This mechanism characterizes XaPobA and sheds light on the diversity of catalytic mechanisms of PobA-type PHBHs and group A flavoprotein monooxygenases.
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Affiliation(s)
- Nozomi Katsuki
- Faculty of Life and Environmental Sciences, Microbiology Research Center for Sustainability, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Riku Fukushima
- Department of Biotechnology, The University of Tokyo, Tokyo, Japan
| | - Yuki Doi
- Faculty of Life and Environmental Sciences, Microbiology Research Center for Sustainability, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Shunsuke Masuo
- Faculty of Life and Environmental Sciences, Microbiology Research Center for Sustainability, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Takatoshi Arakawa
- Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda, Chiba, Japan
| | - Chihaya Yamada
- School of Agriculture, Meiji University, Kawasaki, Kanagawa, Japan
| | - Shinya Fushinobu
- Department of Biotechnology, The University of Tokyo, Tokyo, Japan; Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo, Japan.
| | - Naoki Takaya
- Faculty of Life and Environmental Sciences, Microbiology Research Center for Sustainability, University of Tsukuba, Tsukuba, Ibaraki, Japan.
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6
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Phintha A, Chaiyen P. Unifying and versatile features of flavin-dependent monooxygenases: Diverse catalysis by a common C4a-(hydro)peroxyflavin. J Biol Chem 2023; 299:105413. [PMID: 37918809 PMCID: PMC10696468 DOI: 10.1016/j.jbc.2023.105413] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 10/18/2023] [Accepted: 10/22/2023] [Indexed: 11/04/2023] Open
Abstract
Flavin-dependent monooxygenases (FDMOs) are known for their remarkable versatility and for their crucial roles in various biological processes and applications. Extensive research has been conducted to explore the structural and functional relationships of FDMOs. The majority of reported FDMOs utilize C4a-(hydro)peroxyflavin as a reactive intermediate to incorporate an oxygen atom into a wide range of compounds. This review discusses and analyzes recent advancements in our understanding of the structural and mechanistic features governing the enzyme functions. State-of-the-art discoveries related to common and distinct structural properties governing the catalytic versatility of the C4a-(hydro)peroxyflavin intermediate in selected FDMOs are discussed. Specifically, mechanisms of hydroxylation, dehalogenation, halogenation, and light-emitting reactions by FDMOs are highlighted. We also provide new analysis based on the structural and mechanistic features of these enzymes to gain insights into how the same intermediate can be harnessed to perform a wide variety of reactions. Challenging questions to obtain further breakthroughs in the understanding of FDMOs are also proposed.
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Affiliation(s)
- Aisaraphon Phintha
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Wangchan Valley, Rayong, Thailand
| | - Pimchai Chaiyen
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Wangchan Valley, Rayong, Thailand.
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7
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Wang Q, Liu N, Deng Y, Guan Y, Xiao H, Nitka TA, Yang H, Yadav A, Vukovic L, Mathews II, Chen X, Kim CY. Triepoxide formation by a flavin-dependent monooxygenase in monensin biosynthesis. Nat Commun 2023; 14:6273. [PMID: 37805629 PMCID: PMC10560226 DOI: 10.1038/s41467-023-41889-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Accepted: 09/18/2023] [Indexed: 10/09/2023] Open
Abstract
Monensin A is a prototypical natural polyether polyketide antibiotic. It acts by binding a metal cation and facilitating its transport across the cell membrane. Biosynthesis of monensin A involves construction of a polyene polyketide backbone, subsequent epoxidation of the alkenes, and, lastly, formation of cyclic ethers via epoxide-opening cyclization. MonCI, a flavin-dependent monooxygenase, is thought to transform all three alkenes in the intermediate polyketide premonensin A into epoxides. Our crystallographic study has revealed that MonCI's exquisite stereocontrol is due to the preorganization of the active site residues which allows only one specific face of the alkene to approach the reactive C(4a)-hydroperoxyflavin moiety. Furthermore, MonCI has an unusually large substrate-binding cavity that can accommodate premonensin A in an extended or folded conformation which allows any of the three alkenes to be placed next to C(4a)-hydroperoxyflavin. MonCI, with its ability to perform multiple epoxidations on the same substrate in a stereospecific manner, demonstrates the extraordinary versatility of the flavin-dependent monooxygenase family of enzymes.
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Affiliation(s)
- Qian Wang
- Department of Chemistry and Biochemistry, The University of Texas at El Paso, 500 West University Avenue, El Paso, TX, 79968, USA
| | - Ning Liu
- Key Laboratory of Synthetic and Natural Functional Molecular Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, 710127, Xi'an, China
| | - Yaming Deng
- Key Laboratory of Synthetic and Natural Functional Molecular Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, 710127, Xi'an, China
| | - Yuze Guan
- Key Laboratory of Synthetic and Natural Functional Molecular Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, 710127, Xi'an, China
| | - Hongli Xiao
- Key Laboratory of Synthetic and Natural Functional Molecular Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, 710127, Xi'an, China
| | - Tara A Nitka
- Department of Chemistry and Biochemistry, The University of Texas at El Paso, 500 West University Avenue, El Paso, TX, 79968, USA
| | - Hui Yang
- Key Laboratory of Synthetic and Natural Functional Molecular Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, 710127, Xi'an, China
| | - Anju Yadav
- Department of Chemistry and Biochemistry, The University of Texas at El Paso, 500 West University Avenue, El Paso, TX, 79968, USA
| | - Lela Vukovic
- Department of Chemistry and Biochemistry, The University of Texas at El Paso, 500 West University Avenue, El Paso, TX, 79968, USA
| | - Irimpan I Mathews
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 95124, USA
| | - Xi Chen
- Key Laboratory of Synthetic and Natural Functional Molecular Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, 710127, Xi'an, China.
| | - Chu-Young Kim
- Department of Chemistry and Biochemistry, The University of Texas at El Paso, 500 West University Avenue, El Paso, TX, 79968, USA.
- Department of Biochemistry, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA.
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8
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Ernst S, Mährlein A, Ritzmann NH, Drees SL, Fetzner S. A comparative study of
N
‐hydroxylating flavoprotein monooxygenases reveals differences in kinetics and cofactor binding. FEBS J 2022; 289:5637-5655. [DOI: 10.1111/febs.16444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 02/21/2022] [Accepted: 03/18/2022] [Indexed: 12/01/2022]
Affiliation(s)
- Simon Ernst
- Institute of Molecular Microbiology and Biotechnology University of Münster Germany
| | - Almuth Mährlein
- Institute of Molecular Microbiology and Biotechnology University of Münster Germany
| | - Niklas H. Ritzmann
- Institute of Molecular Microbiology and Biotechnology University of Münster Germany
| | - Steffen L. Drees
- Institute of Molecular Microbiology and Biotechnology University of Münster Germany
| | - Susanne Fetzner
- Institute of Molecular Microbiology and Biotechnology University of Münster Germany
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9
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Suzuki K, Maeda S. Multistructural microiteration combined with QM/MM-ONIOM electrostatic embedding. Phys Chem Chem Phys 2022; 24:16762-16773. [PMID: 35775395 DOI: 10.1039/d2cp02270b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Multistructural microiteration (MSM) is a method to take account of contributions of multiple surrounding structures in a geometrical optimization or reaction path calculation using the quantum mechanics/molecular mechanics (QM/MM) ONIOM method. In this study, we combined MSM with the electrostatic embedding (EE) scheme of the QM/MM-ONIOM method by extending its original formulation for mechanical embedding (ME). MSM-EE takes account of the polarization in the QM region induced by point charges assigned to atoms in the multiple surrounding structures, where the point charges are scaled by the weight factor of each surrounding structure determined through MSM. The performance of MSM-EE was compared with that of the other methods, i.e., ONIOM-ME, ONIOM-EE, and MSM-ME, by applying them to three chemical processes: (1) chorismate-to-prephenate transformation in aqueous solution, (2) the same transformation as (1) in an enzyme, and (3) hydroxylation in p-hydroxybenzoate hydroxylase. These numerical tests of MSM-EE yielded barriers and reaction energies close to experimental values with computational costs comparable to those of the other three methods.
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Affiliation(s)
- Kimichi Suzuki
- Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Sapporo 001-0021, Japan. .,Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan.,JST, ERATO Maeda Artificial Intelligence for Chemical Reaction Design and Discovery Project, Sapporo 060-0810, Japan
| | - Satoshi Maeda
- Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Sapporo 001-0021, Japan. .,Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan.,JST, ERATO Maeda Artificial Intelligence for Chemical Reaction Design and Discovery Project, Sapporo 060-0810, Japan.,Research and Services Division of Materials Data and Integrated System (MaDIS), National Institute for Materials Science (NIMS), Tsukuba 305-0044, Japan
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10
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Debottlenecking 4-hydroxybenzoate hydroxylation in Pseudomonas putida KT2440 improves muconate productivity from p-coumarate. Metab Eng 2022; 70:31-42. [PMID: 34982998 DOI: 10.1016/j.ymben.2021.12.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 12/15/2021] [Accepted: 12/29/2021] [Indexed: 12/31/2022]
Abstract
The transformation of 4-hydroxybenzoate (4-HBA) to protocatechuate (PCA) is catalyzed by flavoprotein oxygenases known as para-hydroxybenzoate-3-hydroxylases (PHBHs). In Pseudomonas putida KT2440 (P. putida) strains engineered to convert lignin-related aromatic compounds to muconic acid (MA), PHBH activity is rate-limiting, as indicated by the accumulation of 4-HBA, which ultimately limits MA productivity. Here, we hypothesized that replacement of PobA, the native P. putida PHBH, with PraI, a PHBH from Paenibacillus sp. JJ-1b with a broader nicotinamide cofactor preference, could alleviate this bottleneck. Biochemical assays confirmed the strict preference of NADPH for PobA, while PraI can utilize either NADH or NADPH. Kinetic assays demonstrated that both PobA and PraI can utilize NADPH with comparable catalytic efficiency and that PraI also efficiently utilizes NADH at roughly half the catalytic efficiency. The X-ray crystal structure of PraI was solved and revealed absolute conservation of the active site architecture to other PHBH structures despite their differing cofactor preferences. To understand the effect in vivo, we compared three P. putida strains engineered to produce MA from p-coumarate (pCA), showing that expression of praI leads to lower 4-HBA accumulation and decreased NADP+/NADPH ratios relative to strains harboring pobA, indicative of a relieved 4-HBA bottleneck due to increased NADPH availability. In bioreactor cultivations, a strain exclusively expressing praI achieved a titer of 40 g/L MA at 100% molar yield and a productivity of 0.5 g/L/h. Overall, this study demonstrates the benefit of sampling readily available natural enzyme diversity for debottlenecking metabolic flux in an engineered strain for microbial conversion of lignin-derived compounds to value-added products.
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11
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Manzoor MM, Goyal P, Pandotra P, Dar MS, Dar MJ, Misra P, Gupta AP, Vishwakarma RA, Ahuja A, Dhar MK, Gupta S. Transcriptome-wide identification of squalene epoxidase genes from Glycyrrhiza glabra L.: expression analysis and heterologous expression of GgSQE1 suggest important role in terpenoid biosynthesis. PROTOPLASMA 2021; 258:991-1007. [PMID: 33629144 PMCID: PMC7904238 DOI: 10.1007/s00709-021-01616-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 01/22/2021] [Indexed: 05/27/2023]
Abstract
Squalene epoxidase (SQE) is a crucial regulatory enzyme for the biosynthesis of several important classes of compounds including sterols and triterpenoids. The present paper identified and characterised five SQE genes (GgSQE1 to GgSQE5) from Glycyrrhiza glabra through transcriptome data mining and homology-based cloning, for the first time. The phylogenetic analysis implied their functional divergence. The ORF corresponding to one of the five SQEs, namely, GgSQE1, was cloned and studied for its function in a heterologous system, following transient and stable expressions. The transient expression followed by GgSQE1 encoding protein purification suggested approximately 58.0-kDa protein following the predicted molecular mass of the deduced protein. The gene expression profiling based on qRT-PCR indicated its highest expression (6.4-folds) in the 10-month-old roots. Furthermore, ABA (12.4-folds) and GA3 (2.47) treatments upregulated the expression of GgSQE1 in the shoots after 10 and 12 hours, respectively, which was also reflected in glycyrrhizin accumulation. The inductive effects of ABA and GA3 over GgSQE1 expression were also confirmed through functional analysis of GgSQE1 promoters using GUS fusion construct. Stable constitutive expression of GgSQE1 in Nicotiana tabacum modulated the sterol contents. The study could pave the way for understanding the metabolic flux regulation concerning biosynthesis of related sterols and triterpenoids.
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Affiliation(s)
- Malik Muzafar Manzoor
- Plant Biotechnology Division, CSIR-IIIM, Jammu, India
- Council of Scientific and Industrial Research (CSIR), Indian Institute of Integrative Medicine, Canal Road, Jammu, ,180001, India
| | - Pooja Goyal
- Plant Biotechnology Division, CSIR-IIIM, Jammu, India
- Council of Scientific and Industrial Research (CSIR), Indian Institute of Integrative Medicine, Canal Road, Jammu, ,180001, India
| | - Pankaj Pandotra
- Plant Biotechnology Division, CSIR-IIIM, Jammu, India
- Sher-e-Kashmir University, Jammu, India
| | - Mohd Saleem Dar
- Council of Scientific and Industrial Research (CSIR), Indian Institute of Integrative Medicine, Canal Road, Jammu, ,180001, India
- Cancer Pharmacology Division, CSIR-IIIM, Jammu, India
- Department of Biochemistry, Purdue University, West Lafayette, IN, 47907, USA
| | - Mohd Jamal Dar
- Council of Scientific and Industrial Research (CSIR), Indian Institute of Integrative Medicine, Canal Road, Jammu, ,180001, India
- Cancer Pharmacology Division, CSIR-IIIM, Jammu, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Prashant Misra
- Plant Biotechnology Division, CSIR-IIIM, Jammu, India.
- Council of Scientific and Industrial Research (CSIR), Indian Institute of Integrative Medicine, Canal Road, Jammu, ,180001, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
| | - Ajai P Gupta
- Council of Scientific and Industrial Research (CSIR), Indian Institute of Integrative Medicine, Canal Road, Jammu, ,180001, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
- Quality Control and Quality Assurance Division, CSIR-IIIM, Jammu, India
| | - Ram A Vishwakarma
- Council of Scientific and Industrial Research (CSIR), Indian Institute of Integrative Medicine, Canal Road, Jammu, ,180001, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Ashok Ahuja
- Council of Scientific and Industrial Research (CSIR), Indian Institute of Integrative Medicine, Canal Road, Jammu, ,180001, India
| | - Manoj K Dhar
- Genome Research Laboratory, School of Biotechnology, University of Jammu, Jammu, India
- Jammu University, Jammu, India
| | - Suphla Gupta
- Plant Biotechnology Division, CSIR-IIIM, Jammu, India.
- Council of Scientific and Industrial Research (CSIR), Indian Institute of Integrative Medicine, Canal Road, Jammu, ,180001, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
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12
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Lahham M, Jha S, Goj D, Macheroux P, Wallner S. The family of sarcosine oxidases: Same reaction, different products. Arch Biochem Biophys 2021; 704:108868. [PMID: 33812916 DOI: 10.1016/j.abb.2021.108868] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 03/26/2021] [Accepted: 03/27/2021] [Indexed: 12/11/2022]
Abstract
The subfamily of sarcosine oxidase is a set of enzymes within the larger family of amine oxidases. It is ubiquitously distributed among different kingdoms of life. The member enzymes catalyze the oxidization of an N-methyl amine bond of amino acids to yield unstable imine species that undergo subsequent spontaneous non-enzymatic reactions, forming an array of different products. These products range from demethylated simple species to complex alkaloids. The enzymes belonging to the sarcosine oxidase family, namely, monomeric and heterotetrameric sarcosine oxidase, l-pipecolate oxidase, N-methyltryptophan oxidase, NikD, l-proline dehydrogenase, FsqB, fructosamine oxidase and saccharopine oxidase have unique features differentiating them from other amine oxidases. This review highlights the key attributes of the sarcosine oxidase family enzymes, in terms of their substrate binding motif, type of oxidation reaction mediated and FAD regeneration, to define the boundaries of this group and demarcate these enzymes from other amine oxidase families.
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Affiliation(s)
- Majd Lahham
- Institute of Biochemistry, Graz University of Technology, NAWI Graz, Graz, Austria; Department of Biochemistry and Microbiology, Aljazeera Private University, Ghabagheb, Syria
| | - Shalinee Jha
- Institute of Biochemistry, Graz University of Technology, NAWI Graz, Graz, Austria
| | - Dominic Goj
- Institute of Biochemistry, Graz University of Technology, NAWI Graz, Graz, Austria
| | - Peter Macheroux
- Institute of Biochemistry, Graz University of Technology, NAWI Graz, Graz, Austria
| | - Silvia Wallner
- Institute of Biochemistry, Graz University of Technology, NAWI Graz, Graz, Austria.
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13
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Westphal AH, Tischler D, van Berkel WJH. Natural diversity of FAD-dependent 4-hydroxybenzoate hydroxylases. Arch Biochem Biophys 2021; 702:108820. [PMID: 33684360 DOI: 10.1016/j.abb.2021.108820] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 02/19/2021] [Accepted: 02/21/2021] [Indexed: 01/05/2023]
Abstract
4-Hydroxybenzoate 3-hydroxylase (PHBH) is the most extensively studied group A flavoprotein monooxygenase (FPMO). PHBH is almost exclusively found in prokaryotes, where its induction, usually as a consequence of lignin degradation, results in the regioselective formation of protocatechuate, one of the central intermediates in the global carbon cycle. In this contribution we introduce several less known FAD-dependent 4-hydroxybenzoate hydroxylases. Phylogenetic analysis showed that the enzymes discussed here reside in distinct clades of the group A FPMO family, indicating their separate divergence from a common ancestor. Protein homology modelling revealed that the fungal 4-hydroxybenzoate 3-hydroxylase PhhA is structurally related to phenol hydroxylase (PHHY) and 3-hydroxybenzoate 4-hydroxylase (3HB4H). 4-Hydroxybenzoate 1-hydroxylase (4HB1H) from yeast catalyzes an oxidative decarboxylation reaction and is structurally similar to 3-hydroxybenzoate 6-hydroxylase (3HB6H), salicylate hydroxylase (SALH) and 6-hydroxynicotinate 3-monooxygenase (6HNMO). Genome mining suggests that the 4HB1H activity is widespread in the fungal kingdom and might be responsible for the oxidative decarboxylation of vanillate, an import intermediate in lignin degradation. 4-Hydroxybenzoyl-CoA 1-hydroxylase (PhgA) catalyzes an intramolecular migration reaction (NIH shift) during the three-step conversion of 4-hydroxybenzoate to gentisate in certain Bacillus species. PhgA is phylogenetically related to 4-hydroxyphenylacetate 1-hydroxylase (4HPA1H). In summary, this paper shines light on the natural diversity of group A FPMOs that are involved in the aerobic microbial catabolism of 4-hydroxybenzoate.
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Affiliation(s)
- Adrie H Westphal
- Laboratory of Biochemistry, Wageningen University & Research, Wageningen, the Netherlands.
| | - Dirk Tischler
- Microbial Biotechnology, Faculty of Biology and Biotechnology, Ruhr-Universität Bochum, Germany.
| | - Willem J H van Berkel
- Laboratory of Food Chemistry, Wageningen University & Research, Wageningen, the Netherlands.
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14
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Paul CE, Eggerichs D, Westphal AH, Tischler D, van Berkel WJH. Flavoprotein monooxygenases: Versatile biocatalysts. Biotechnol Adv 2021; 51:107712. [PMID: 33588053 DOI: 10.1016/j.biotechadv.2021.107712] [Citation(s) in RCA: 63] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 01/27/2021] [Accepted: 02/06/2021] [Indexed: 12/13/2022]
Abstract
Flavoprotein monooxygenases (FPMOs) are single- or two-component enzymes that catalyze a diverse set of chemo-, regio- and enantioselective oxyfunctionalization reactions. In this review, we describe how FPMOs have evolved from model enzymes in mechanistic flavoprotein research to biotechnologically relevant catalysts that can be applied for the sustainable production of valuable chemicals. After a historical account of the development of the FPMO field, we explain the FPMO classification system, which is primarily based on protein structural properties and electron donor specificities. We then summarize the most appealing reactions catalyzed by each group with a focus on the different types of oxygenation chemistries. Wherever relevant, we report engineering strategies that have been used to improve the robustness and applicability of FPMOs.
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Affiliation(s)
- Caroline E Paul
- Biocatalysis, Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Daniel Eggerichs
- Microbial Biotechnology, Faculty of Biology and Biotechnology, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany
| | - Adrie H Westphal
- Laboratory of Biochemistry, Wageningen University, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Dirk Tischler
- Microbial Biotechnology, Faculty of Biology and Biotechnology, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany
| | - Willem J H van Berkel
- Laboratory of Food Chemistry, Wageningen University, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands.
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15
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Reis RAG, Li H, Johnson M, Sobrado P. New frontiers in flavin-dependent monooxygenases. Arch Biochem Biophys 2021; 699:108765. [PMID: 33460580 DOI: 10.1016/j.abb.2021.108765] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 01/08/2021] [Accepted: 01/11/2021] [Indexed: 12/15/2022]
Abstract
Flavin-dependent monooxygenases catalyze a wide variety of redox reactions in important biological processes and are responsible for the synthesis of highly complex natural products. Although much has been learned about FMO chemistry in the last ~80 years of research, several aspects of the reactions catalyzed by these enzymes remain unknown. In this review, we summarize recent advancements in the flavin-dependent monooxygenase field including aspects of flavin dynamics, formation and stabilization of reactive species, and the hydroxylation mechanism. Novel catalysis of flavin-dependent N-oxidases involving consecutive oxidations of amines to generate oximes or nitrones is presented and the biological relevance of the products is discussed. In addition, the activity of some FMOs have been shown to be essential for the virulence of several human pathogens. We also discuss the biomedical relevance of FMOs in antibiotic resistance and the efforts to identify inhibitors against some members of this important and growing family enzymes.
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Affiliation(s)
| | - Hao Li
- Department of Biochemistry, Blacksburg, VA, 24061, USA
| | - Maxim Johnson
- Department of Biochemistry, Blacksburg, VA, 24061, USA
| | - Pablo Sobrado
- Department of Biochemistry, Blacksburg, VA, 24061, USA; Center for Drug Discovery, Virginia Tech, Blacksburg, VA, 24061, USA.
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16
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Abstract
Many flavin-dependent phenolic hydroxylases (monooxygenases) have been extensively investigated. Their crystal structures and reaction mechanisms are well understood. These enzymes belong to groups A and D of the flavin-dependent monooxygenases and can be classified as single-component and two-component flavin-dependent monooxygenases. The insertion of molecular oxygen into the substrates catalyzed by these enzymes is beneficial for modifying the biological properties of phenolic compounds and their derivatives. This chapter provides an in-depth discussion of the structural features of single-component and two-component flavin-dependent phenolic hydroxylases. The reaction mechanisms of selected enzymes, including 3-hydroxy-benzoate 4-hydroxylase (PHBH) and 3-hydroxy-benzoate 6-hydroxylase as representatives of single-component enzymes and 3-hydroxyphenylacetate 4-hydroxylase (HPAH) as a representative of two-component enzymes, are discussed in detail. This chapter comprises the following four main parts: general reaction, structures, reaction mechanisms, and enzyme engineering for biocatalytic applications. Enzymes belonging to the same group catalyze similar reactions but have different unique structural features to control their reactivity to substrates and the formation and stabilization of C4a-hydroperoxyflavin. Protein engineering has been employed to improve the ability to use these enzymes to synthesize valuable compounds. A thorough understanding of the structural and mechanistic features controlling enzyme reactivity is useful for enzyme redesign and enzyme engineering for future biocatalytic applications.
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Affiliation(s)
- Pirom Chenprakhon
- Institute for Innovative Learning, Mahidol University, Nakhon Pathom, Thailand.
| | - Panu Pimviriyakul
- Department of Biochemistry, Faculty of Science, Kasetsart University, Chatuchak, Bangkok, Thailand; Department of Biotechnology, Faculty of Engineering and Industrial Technology, Silpakorn University, Nakhon Pathom, Thailand
| | - Chanakan Tongsook
- Department of Chemistry, Faculty of Science, Silpakorn University, Nakhon Pathom, Thailand
| | - Pimchai Chaiyen
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Wangchan Valley, Rayong, Thailand
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17
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Beaupre BA, Reabe KR, Roman JV, Moran GR. Hydrogen movements in the oxidative half-reaction of kynurenine 3-monooxygenase from Pseudomonas fluorescens reveal the mechanism of hydroxylation. Arch Biochem Biophys 2020; 690:108474. [PMID: 32687799 DOI: 10.1016/j.abb.2020.108474] [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: 05/01/2020] [Revised: 06/08/2020] [Accepted: 06/17/2020] [Indexed: 11/30/2022]
Abstract
Kynurenine 3-monoxygenase (KMO) catalyzes the conversion of l-kynurenine (L-Kyn) to 3-hydroxykynurenine (3-OHKyn) in the pathway for tryptophan catabolism. We have investigated the effects of pH and deuterium substitution on the oxidative half-reaction of KMO from P. fluorescens (PfKMO). The three phases observed during the oxidative half reaction are formation of the hydroperoxyflavin, hydroxylation and product release. The measured rate constants for these phases proved largely unchanging with pH, suggesting that the KMO active site is insulated from exchange with solvent during catalysis. A solvent inventory study indicated that a solvent isotope effect of 2-3 is observed for the hydroxylation phase and that two or more protons are in flight during this step. An inverse isotope effect of 0.84 ± 0.01 on the rate constant for the hydroxylation step with ring perdeutero-L-Kyn as a substrate indicates a shift from sp2 to sp3 hybridization in the transition state leading to the formation of a non-aromatic intermediate. The pH dependence of transient state data collected for the substrate analog meta-nitrobenzoylalanine indicate that groups proximal to the hydroperoxyflavin are titrated in the range pH 5-8.5 and can be described by a pKa of 8.8. That higher pH values do not slow the rate of hydroxylation precludes that the pKa measured pertains to the proton of the hydroperoxflavin. Together, these observations indicate that the C4a-hydroperoxyflavin has a pKa ≫ 8.5, that a non-aromatic species is the immediate product of hydroxylation and that at least two solvent derived protons are in-flight during oxygen insertion to the substrate aromatic ring. A unifying mechanistic proposal for these observations is proposed.
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Affiliation(s)
- Brett A Beaupre
- Department of Chemistry and Biochemistry, 1068 W Sheridan Rd, Loyola University Chicago, Chicago, IL, 60660, USA
| | - Karen R Reabe
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, 3210 N. Cramer Street, Milwaukee, WI, 53211-3029, USA
| | - Joseph V Roman
- Department of Chemistry and Biochemistry, 1068 W Sheridan Rd, Loyola University Chicago, Chicago, IL, 60660, USA
| | - Graham R Moran
- Department of Chemistry and Biochemistry, 1068 W Sheridan Rd, Loyola University Chicago, Chicago, IL, 60660, USA.
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18
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Chenprakhon P, Wongnate T, Chaiyen P. Monooxygenation of aromatic compounds by flavin-dependent monooxygenases. Protein Sci 2020; 28:8-29. [PMID: 30311986 DOI: 10.1002/pro.3525] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 10/08/2018] [Accepted: 10/08/2018] [Indexed: 12/12/2022]
Abstract
Many flavoenzymes catalyze hydroxylation of aromatic compounds especially phenolic compounds have been isolated and characterized. These enzymes can be classified as either single-component or two-component flavin-dependent hydroxylases (monooxygenases). The hydroxylation reactions catalyzed by the enzymes in this group are useful for modifying the biological properties of phenolic compounds. This review aims to provide an in-depth discussion of the current mechanistic understanding of representative flavin-dependent monooxygenases including 3-hydroxy-benzoate 4-hydroxylase (PHBH, a single-component hydroxylase), 3-hydroxyphenylacetate 4-hydroxylase (HPAH, a two-component hydroxylase), and other monooxygenases which catalyze reactions in addition to hydroxylation, including 2-methyl-3-hydroxypyridine-5-carboxylate oxygenase (MHPCO, a single-component enzyme that catalyzes aromatic-ring cleavage), and HadA monooxygenase (a two-component enzyme that catalyzes additional group elimination reaction). These enzymes have different unique structural features which dictate their reactivity toward various substrates and influence their ability to stabilize flavin intermediates such as C4a-hydroperoxyflavin. Understanding the key catalytic residues and the active site environments important for governing enzyme reactivity will undoubtedly facilitate future work in enzyme engineering or enzyme redesign for the development of biocatalytic methods for the synthesis of valuable compounds.
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Affiliation(s)
- Pirom Chenprakhon
- Institute for Innovative Learning, Mahidol University, Nakhon Pathom, 73170, Thailand
| | - Thanyaporn Wongnate
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong, 21210, Thailand
| | - Pimchai Chaiyen
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong, 21210, Thailand.,Department of Biochemistry and Center for Excellence in Protein and Enzyme Technology, Faculty of Science, Mahidol University, Bangkok, 14000, Thailand
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19
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Guarneri A, Westphal AH, Leertouwer J, Lunsonga J, Franssen MCR, Opperman DJ, Hollmann F, Berkel WJH, Paul CE. Flavoenzyme‐mediated Regioselective Aromatic Hydroxylation with Coenzyme Biomimetics. ChemCatChem 2020. [DOI: 10.1002/cctc.201902044] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Alice Guarneri
- Laboratory of Organic ChemistryWageningen University Stippeneng 4 Wageningen 6708 WE The Netherlands
| | - Adrie H. Westphal
- Laboratory of BiochemistryWageningen University Stippeneng 4 Wageningen 6708 WE The Netherlands
| | - Jos Leertouwer
- Department of BiotechnologyDelft University of Technology Van der Maasweg 9 Delft 2629 HZ The Netherlands
| | - Joy Lunsonga
- Laboratory of Organic ChemistryWageningen University Stippeneng 4 Wageningen 6708 WE The Netherlands
| | - Maurice C. R. Franssen
- Laboratory of Organic ChemistryWageningen University Stippeneng 4 Wageningen 6708 WE The Netherlands
| | - Diederik J. Opperman
- Department of BiotechnologyUniversity of the Free State 205 Nelson Mandela Drive Bloemfontein 9300 South Africa
| | - Frank Hollmann
- Department of BiotechnologyDelft University of Technology Van der Maasweg 9 Delft 2629 HZ The Netherlands
| | - Willem J. H. Berkel
- Laboratory of Food ChemistryWageningen University Bornse Weilanden 9 Wageningen 6708 WG The Netherlands
| | - Caroline E. Paul
- Department of BiotechnologyDelft University of Technology Van der Maasweg 9 Delft 2629 HZ The Netherlands
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20
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Moriwaki Y, Yato M, Terada T, Saito S, Nukui N, Iwasaki T, Nishi T, Kawaguchi Y, Okamoto K, Arakawa T, Yamada C, Fushinobu S, Shimizu K. Understanding the Molecular Mechanism Underlying the High Catalytic Activity of p-Hydroxybenzoate Hydroxylase Mutants for Producing Gallic Acid. Biochemistry 2019; 58:4543-4558. [DOI: 10.1021/acs.biochem.9b00443] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Yoshitaka Moriwaki
- The Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | | | - Tohru Terada
- The Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Seiji Saito
- Department of Medical Management and Informatics, Hokkaido Information University, 59-2, Nishi Nopporo, Ebetsu, Hokkaido 069-8585, Japan
- Genaris, Inc., 75-1 Ono-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0046, Japan
| | - Noriyuki Nukui
- Genaris, Inc., 75-1 Ono-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0046, Japan
| | - Takumi Iwasaki
- Genaris, Inc., 75-1 Ono-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0046, Japan
| | - Tatsunari Nishi
- Genaris, Inc., 75-1 Ono-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0046, Japan
| | - Yuko Kawaguchi
- Department of Biochemistry and Molecular Biology, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-Ku, Tokyo 113-8602, Japan
| | - Ken Okamoto
- Department of Biochemistry and Molecular Biology, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-Ku, Tokyo 113-8602, Japan
| | - Takatoshi Arakawa
- The Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Chihaya Yamada
- The Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Shinya Fushinobu
- The Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Kentaro Shimizu
- The Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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21
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Cui C, Guo C, Lin H, Ding ZY, Liu Y, Wu ZL. Functional characterization of an (R)-selective styrene monooxygenase from streptomyces sp. NRRL S-31. Enzyme Microb Technol 2019; 132:109391. [PMID: 31731956 DOI: 10.1016/j.enzmictec.2019.109391] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 08/01/2019] [Accepted: 08/04/2019] [Indexed: 12/14/2022]
Abstract
Styrene monooxygenases (SMOs) are two-component enzymes known to catalyze the epoxidation of styrene to (S)-styrene oxide. In this work, we identified a new oxygenase component, named StStyA, from the genome of Streptomyces sp. NRRL S-31. StStyA displayed complementary stereoselectivity to all of the known SMOs when coupled with a known reductase component (PsStyB), which made it the first natural SMO that produces (R)-styrene oxide. Accordingly, a plasmid co-expressing StStyA and PsStyB was constructed, which led to an artificial two-component SMO, named StStyA/B. When applied in the bio-epoxidation of nine aromatic alkenes, the enzyme showed activity toward five alkenes, and consistently displayed (R)-selectivity. Excellent stereoselectivity was achieved for all five substrates with enantiomeric excesses ranging from 91% to >99%ee.
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Affiliation(s)
- Can Cui
- Key Laboratory of Environmental and Applied Microbiology, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China; Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu 610041, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chao Guo
- Key Laboratory of Environmental and Applied Microbiology, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China; Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu 610041, China
| | - Hui Lin
- College of Life Sciences, Henan Agricultural University, 95 Wenhua Road, Zhengzhou 450002, China
| | - Zhao-Yun Ding
- Key Laboratory of Environmental and Applied Microbiology, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China; Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu 610041, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yan Liu
- Key Laboratory of Environmental and Applied Microbiology, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China; Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu 610041, China
| | - Zhong-Liu Wu
- Key Laboratory of Environmental and Applied Microbiology, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China; Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu 610041, China.
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22
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Catalytic mechanism for the conversion of salicylate into catechol by the flavin-dependent monooxygenase salicylate hydroxylase. Int J Biol Macromol 2019; 129:588-600. [DOI: 10.1016/j.ijbiomac.2019.01.135] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 01/24/2019] [Accepted: 01/24/2019] [Indexed: 11/17/2022]
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23
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Allen KN, Entova S, Ray LC, Imperiali B. Monotopic Membrane Proteins Join the Fold. Trends Biochem Sci 2019; 44:7-20. [PMID: 30337134 PMCID: PMC6309722 DOI: 10.1016/j.tibs.2018.09.013] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 09/18/2018] [Accepted: 09/19/2018] [Indexed: 12/22/2022]
Abstract
Monotopic membrane proteins, classified by topology, are proteins that embed into a single face of the membrane. These proteins are generally underrepresented in the Protein Data Bank (PDB), but the past decade of research has revealed new examples that allow the description of generalizable features. This Opinion article summarizes shared characteristics including oligomerization states, modes of membrane association, mechanisms of interaction with hydrophobic or amphiphilic substrates, and homology to soluble folds. We also discuss how associations of monotopic enzymes in pathways can be used to promote substrate specificity and product composition. These examples highlight the challenges in structure determination specific to this class of proteins, but also the promise of new understanding from future study of these proteins that reside at the interface.
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Affiliation(s)
- Karen N Allen
- Department of Chemistry, Boston University, Boston, MA 02215, USA; Program in Biomolecular Pharmacology, Boston University School of Medicine, Boston, MA 02118, USA.
| | - Sonya Entova
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Leah C Ray
- Program in Biomolecular Pharmacology, Boston University School of Medicine, Boston, MA 02118, USA
| | - Barbara Imperiali
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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24
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Westphal AH, Tischler D, Heinke F, Hofmann S, Gröning JAD, Labudde D, van Berkel WJH. Pyridine Nucleotide Coenzyme Specificity of p-Hydroxybenzoate Hydroxylase and Related Flavoprotein Monooxygenases. Front Microbiol 2018; 9:3050. [PMID: 30631308 PMCID: PMC6315137 DOI: 10.3389/fmicb.2018.03050] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 11/27/2018] [Indexed: 12/03/2022] Open
Abstract
p-Hydroxybenzoate hydroxylase (PHBH; EC 1.14.13.2) is a microbial group A flavoprotein monooxygenase that catalyzes the ortho-hydroxylation of 4-hydroxybenzoate to 3,4-dihydroxybenzoate with the stoichiometric consumption of NAD(P)H and oxygen. PHBH and related enzymes lack a canonical NAD(P)H-binding domain and the way they interact with the pyridine nucleotide coenzyme has remained a conundrum. Previously, we identified a surface exposed protein segment of PHBH from Pseudomonas fluorescens involved in NADPH binding. Here, we report the first amino acid sequences of NADH-preferring PHBHs and a phylogenetic analysis of putative PHBHs identified in currently available bacterial genomes. It was found that PHBHs group into three clades consisting of NADPH-specific, NAD(P)H-dependent and NADH-preferring enzymes. The latter proteins frequently occur in Actinobacteria. To validate the results, we produced several putative PHBHs in Escherichia coli and confirmed their predicted coenzyme preferences. Based on phylogeny, protein energy profiling and lifestyle of PHBH harboring bacteria we propose that the pyridine nucleotide coenzyme specificity of PHBH emerged through adaptive evolution and that the NADH-preferring enzymes are the older versions of PHBH. Structural comparison and distance tree analysis of group A flavoprotein monooxygenases indicated that a similar protein segment as being responsible for the pyridine nucleotide coenzyme specificity of PHBH is involved in determining the pyridine nucleotide coenzyme specificity of the other group A members.
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Affiliation(s)
- Adrie H Westphal
- Laboratory of Biochemistry, Wageningen University and Research, Wageningen, Netherlands
| | - Dirk Tischler
- Interdisziplinäres Ökologisches Zentrum, Technische Universität Bergakademie Freiberg, Freiberg, Germany
| | - Florian Heinke
- Bioinformatics Group Mittweida, University of Applied Sciences Mittweida, Mittweida, Germany
| | - Sarah Hofmann
- Interdisziplinäres Ökologisches Zentrum, Technische Universität Bergakademie Freiberg, Freiberg, Germany
| | - Janosch A D Gröning
- Interdisziplinäres Ökologisches Zentrum, Technische Universität Bergakademie Freiberg, Freiberg, Germany
| | - Dirk Labudde
- Bioinformatics Group Mittweida, University of Applied Sciences Mittweida, Mittweida, Germany
| | - Willem J H van Berkel
- Laboratory of Biochemistry, Wageningen University and Research, Wageningen, Netherlands
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25
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Insights into the decarboxylative hydroxylation of salicylate catalyzed by the Flavin-dependent monooxygenase salicylate hydroxylase. Theor Chem Acc 2018. [DOI: 10.1007/s00214-018-2278-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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26
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Keirsse-Haquin J, Picaud T, Bordes L, de Gracia AG, Desbois A. Modulation of the flavin-protein interactions in NADH peroxidase and mercuric ion reductase: a resonance Raman study. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2017; 47:205-223. [PMID: 28889232 DOI: 10.1007/s00249-017-1245-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 07/12/2017] [Accepted: 07/26/2017] [Indexed: 10/18/2022]
Abstract
NADH peroxidase (Npx) and mercuric ion reductase (MerA) are flavoproteins belonging to the pyridine nucleotide:disulfide oxidoreductases (PNDO) and catalyzing the reduction of toxic substrates, i.e., hydrogen peroxide and mercuric ion, respectively. To determine the role of the flavin adenine dinucleotide (FAD) in the detoxification mechanism, the resonance Raman (RR) spectra of these enzymes under various redox and ligation states have been investigated using blue and/or near-UV excitation(s). These data were compared to those previously obtained for glutathione reductase (GR), another enzyme of the PNDO family, but catalyzing the reduction of oxidized glutathione. Spectral differences have been detected for the marker bands of the isoalloxazine ring of Npx, MerA, and GR. They provide evidence for different catalytic mechanisms in these flavoproteins. The RR modes of the oxidized and two-electron reduced (EH2) forms of Npx are related to very tight flavin-protein interactions maintaining a nearly planar conformation of the isoalloxazine tricycle, a low level of H-bonding at the N1/N5 and O2/O4 sites, and a strong H-bond at N3H. They also indicate minimal changes in FAD structure and environment upon either NAD(H) binding or reduction of the sulfinic redox center. All these spectroscopic data support an enzyme functioning centered on the Cys-SO-/Cys-S- redox moiety and a neighbouring His residue. On the contrary, the RR data on various functional forms of MerA are indicative of a modulation of both ring II distortion and H-bonding states of the N5 site and ring III. The Cd(II) binding to the EH2-NADP(H) complexes, biomimetic intermediates in the reaction of Hg(II) reduction, provokes important spectral changes. They are interpreted in terms of flattening of the isoalloxazine ring and large decreases in H-bonding at the N5 site and ring III. The large flexibility of the FAD structure and environment in MerA is in agreement with proposed mechanisms involving C4a(flavin) adducts.
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Affiliation(s)
- Julie Keirsse-Haquin
- Institut de Biologie Intégrative de la Cellule, UMR 9198 CNRS-CEA-Université Paris Sud, CEA Saclay, 91191, Gif-sur-Yvette Cedex, France.,Ecole Nationale Supérieure des Mines, 44300, Nantes, France
| | - Thierry Picaud
- Institut de Biologie Intégrative de la Cellule, UMR 9198 CNRS-CEA-Université Paris Sud, CEA Saclay, 91191, Gif-sur-Yvette Cedex, France.,Institut Supérieur des Biotechnologies de Paris (Sup'Biotech Paris), 94800, Villejuif, France
| | - Luc Bordes
- Institut de Biologie Intégrative de la Cellule, UMR 9198 CNRS-CEA-Université Paris Sud, CEA Saclay, 91191, Gif-sur-Yvette Cedex, France.,School of Earth and Environmental Sciences, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Adrienne Gomez de Gracia
- Institut de Biologie Intégrative de la Cellule, UMR 9198 CNRS-CEA-Université Paris Sud, CEA Saclay, 91191, Gif-sur-Yvette Cedex, France
| | - Alain Desbois
- Institut de Biologie Intégrative de la Cellule, UMR 9198 CNRS-CEA-Université Paris Sud, CEA Saclay, 91191, Gif-sur-Yvette Cedex, France.
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Yoon J, Kim SB, Ahmed G, Shay JW, Terman JR. Amplification of F-Actin Disassembly and Cellular Repulsion by Growth Factor Signaling. Dev Cell 2017; 42:117-129.e8. [PMID: 28689759 DOI: 10.1016/j.devcel.2017.06.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 04/10/2017] [Accepted: 06/06/2017] [Indexed: 01/09/2023]
Abstract
Extracellular cues that regulate cellular shape, motility, and navigation are generally classified as growth promoting (i.e., growth factors/chemoattractants and attractive guidance cues) or growth preventing (i.e., repellents and inhibitors). Yet, these designations are often based on complex assays and undefined signaling pathways and thus may misrepresent direct roles of specific cues. Here, we find that a recognized growth-promoting signaling pathway amplifies the F-actin disassembly and repulsive effects of a growth-preventing pathway. Focusing on Semaphorin/Plexin repulsion, we identified an interaction between the F-actin-disassembly enzyme Mical and the Abl tyrosine kinase. Biochemical assays revealed Abl phosphorylates Mical to directly amplify Mical Redox-mediated F-actin disassembly. Genetic assays revealed that Abl allows growth factors and Semaphorin/Plexin repellents to combinatorially increase Mical-mediated F-actin disassembly, cellular remodeling, and repulsive axon guidance. Similar roles for Mical in growth factor/Abl-related cancer cell behaviors further revealed contexts in which characterized positive effectors of growth/guidance stimulate such negative cellular effects as F-actin disassembly/repulsion.
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Affiliation(s)
- Jimok Yoon
- Departments of Neuroscience and Pharmacology, Harold C. Simmons Comprehensive Cancer Center, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Sang Bum Kim
- Department of Cell Biology, Harold C. Simmons Comprehensive Cancer Center, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Giasuddin Ahmed
- Departments of Neuroscience and Pharmacology, Harold C. Simmons Comprehensive Cancer Center, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jerry W Shay
- Department of Cell Biology, Harold C. Simmons Comprehensive Cancer Center, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jonathan R Terman
- Departments of Neuroscience and Pharmacology, Harold C. Simmons Comprehensive Cancer Center, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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Vanoni MA. Structure-function studies of MICAL, the unusual multidomain flavoenzyme involved in actin cytoskeleton dynamics. Arch Biochem Biophys 2017; 632:118-141. [PMID: 28602956 DOI: 10.1016/j.abb.2017.06.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Revised: 05/27/2017] [Accepted: 06/05/2017] [Indexed: 12/11/2022]
Abstract
MICAL (from the Molecule Interacting with CasL) indicates a family of multidomain proteins conserved from insects to humans, which are increasingly attracting attention for their participation in the control of actin cytoskeleton dynamics, and, therefore, in the several related key processes in health and disease. MICAL is unique among actin binding proteins because it catalyzes a NADPH-dependent F-actin depolymerizing reaction. This unprecedented reaction is associated with its N-terminal FAD-containing domain that is structurally related to p-hydroxybenzoate hydroxylase, the prototype of aromatic monooxygenases, but catalyzes a strong NADPH oxidase activity in the free state. This review will focus on the known structural and functional properties of MICAL forms in order to provide an overview of the arguments supporting the current hypotheses on the possible mechanism of action of MICAL in the free and F-actin bound state, on the modulating effect of the CH, LIM, and C-terminal domains that follow the catalytic flavoprotein domain on the MICAL activities, as well as that of small molecules and proteins interacting with MICAL.
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Affiliation(s)
- Maria Antonietta Vanoni
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milano, Italy.
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Ismail A, Leroux V, Smadja M, Gonzalez L, Lombard M, Pierrel F, Mellot-Draznieks C, Fontecave M. Coenzyme Q Biosynthesis: Evidence for a Substrate Access Channel in the FAD-Dependent Monooxygenase Coq6. PLoS Comput Biol 2016; 12:e1004690. [PMID: 26808124 PMCID: PMC4726752 DOI: 10.1371/journal.pcbi.1004690] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 12/03/2015] [Indexed: 02/06/2023] Open
Abstract
Coq6 is an enzyme involved in the biosynthesis of coenzyme Q, a polyisoprenylated benzoquinone lipid essential to the function of the mitochondrial respiratory chain. In the yeast Saccharomyces cerevisiae, this putative flavin-dependent monooxygenase is proposed to hydroxylate the benzene ring of coenzyme Q (ubiquinone) precursor at position C5. We show here through biochemical studies that Coq6 is a flavoprotein using FAD as a cofactor. Homology models of the Coq6-FAD complex are constructed and studied through molecular dynamics and substrate docking calculations of 3-hexaprenyl-4-hydroxyphenol (4-HP6), a bulky hydrophobic model substrate. We identify a putative access channel for Coq6 in a wild type model and propose in silico mutations positioned at its entrance capable of partially (G248R and L382E single mutations) or completely (a G248R-L382E double-mutation) blocking access to the channel for the substrate. Further in vivo assays support the computational predictions, thus explaining the decreased activities or inactivation of the mutated enzymes. This work provides the first detailed structural information of an important and highly conserved enzyme of ubiquinone biosynthesis.
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Affiliation(s)
- Alexandre Ismail
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, UPMC Univ Paris 06, Collège de France, Paris, France
- Sup’Biotech, IONIS Education Group, Villejuif, France
| | - Vincent Leroux
- Paris Sciences et Lettres (PSL*), Collège de France, Center for Interdisciplinary Research in Biology (CIRB), INSERM U1050, Paris, France
| | - Myriam Smadja
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, UPMC Univ Paris 06, Collège de France, Paris, France
| | - Lucie Gonzalez
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, UPMC Univ Paris 06, Collège de France, Paris, France
| | - Murielle Lombard
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, UPMC Univ Paris 06, Collège de France, Paris, France
| | - Fabien Pierrel
- Université Grenoble Alpes, Laboratoire Adaptation et Pathogénie des Microorganismes, Grenoble, France
- CNRS, Laboratoire Adaptation et Pathogénie des Microorganismes, Grenoble, France
| | - Caroline Mellot-Draznieks
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, UPMC Univ Paris 06, Collège de France, Paris, France
| | - Marc Fontecave
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, UPMC Univ Paris 06, Collège de France, Paris, France
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Uemura T, Kita A, Watanabe Y, Adachi M, Kuroki R, Morimoto Y. The catalytic mechanism of decarboxylative hydroxylation of salicylate hydroxylase revealed by crystal structure analysis at 2.5 Å resolution. Biochem Biophys Res Commun 2016; 469:158-63. [DOI: 10.1016/j.bbrc.2015.11.087] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 11/19/2015] [Indexed: 10/22/2022]
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Pang AH, Garneau-Tsodikova S, Tsodikov OV. Crystal structure of halogenase PltA from the pyoluteorin biosynthetic pathway. J Struct Biol 2015; 192:349-357. [PMID: 26416533 DOI: 10.1016/j.jsb.2015.09.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 09/24/2015] [Accepted: 09/25/2015] [Indexed: 10/23/2022]
Abstract
Pyoluteorin is an antifungal agent composed of a 4,5-dichlorinated pyrrole group linked to a resorcinol moiety. The pyoluteorin biosynthetic gene cluster in Pseudomonas fluorescens Pf-5 encodes the halogenase PltA, which has been previously demonstrated to perform both chlorinations in vitro. PltA selectively accepts as a substrate a pyrrole moiety covalently tethered to a nonribosomal peptide thiolation domain PltL (pyrrolyl-S-PltL) for FAD-dependent di-chlorination, yielding 4,5-dichloropyrrolyl-S-PltL. We report a 2.75 Å-resolution crystal structure of PltA in complex with FAD and chloride. PltA is a dimeric enzyme, containing a flavin-binding fold conserved in flavin-dependent halogenases and monooxygenases, and an additional unique helical region at the C-terminus. This C-terminal region blocks a putative substrate-binding cleft, suggesting that a conformational change involving repositioning of this region is necessary to allow binding of the pyrrolyl-S-PltL substrate for its dichlorination by PltA.
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Affiliation(s)
- Allan H Pang
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536-0596, USA
| | - Sylvie Garneau-Tsodikova
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536-0596, USA
| | - Oleg V Tsodikov
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536-0596, USA.
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Kanteev M, Bregman-Cohen A, Deri B, Shahar A, Adir N, Fishman A. A crystal structure of 2-hydroxybiphenyl 3-monooxygenase with bound substrate provides insights into the enzymatic mechanism. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2015; 1854:1906-1913. [PMID: 26275805 DOI: 10.1016/j.bbapap.2015.08.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 08/06/2015] [Accepted: 08/09/2015] [Indexed: 11/16/2022]
Abstract
2-Hydroxybiphenyl 3-monooxygenase (HbpA) is an FAD dependent monooxygenase which catalyzes the ortho-hydroxylation of a broad range of 2-substituted phenols in the presence of NADH and molecular oxygen. We have determined the structure of HbpA from the soil bacterium Pseudomonas azelaica HBP1 with bound 2-hydroxybiphenyl, as well as several variants, at a resolution of 2.3-2.5Å to investigate structure function correlations of the enzyme. An observed hydrogen bond between 2-hydroxybiphenyl and His48 in the active site confirmed the previously suggested role of this residue in substrate deprotonation. The entrance to the active site was confirmed by generating variant G255F which exhibited only 7% of the wild-type's specific activity of product formation, suggesting inhibition of substrate entrance into the active site by the large aromatic residue. Residue Arg242 is suggested to facilitate FAD movement and reduction as was previously reported in studies on the homologous protein para-hydroxybenzoate hydroxylase. In addition, it is suggested that Trp225, which is located in the active site, facilitates proper substrate entrance into the binding pocket in contrast to aklavinone-11-hydroxylase and para-hydroxybenzoate hydroxylase in which a residue at a similar position is responsible for substrate deprotonation. Structure function correlations described in this work will aid in the design of variants with improved activity and altered selectivity for potential industrial applications.
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Affiliation(s)
- Margarita Kanteev
- Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Almog Bregman-Cohen
- Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Batel Deri
- Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Anat Shahar
- Macromolecular Crystallography Research Center (MCRC), Department of Life Sciences & NIBN, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Noam Adir
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa, Israel
| | - Ayelet Fishman
- Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel.
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Hoag MR, Roman J, Beaupre BA, Silvaggi NR, Moran GR. Bacterial Renalase: Structure and Kinetics of an Enzyme with 2- and 6-Dihydro-β-NAD(P) Oxidase Activity from Pseudomonas phaseolicola. Biochemistry 2015; 54:3791-802. [PMID: 26016690 DOI: 10.1021/acs.biochem.5b00451] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Despite a lack of convincing in vitro evidence and a number of sound refutations, it is widely accepted that renalase is an enzyme unique to animals that catalyzes the oxidative degradation of catecholamines in blood in order to lower vascular tone. Very recently, we identified isomers of β-NAD(P)H as substrates for renalase (Beaupre, B. A. et al. (2015) Biochemistry, 54, 795-806). These molecules carry the hydride equivalent on the 2 or 6 position of the nicotinamide base and presumably arise in nonspecific redox reactions of nicotinamide dinucleotides. Renalase serves to rapidly oxidize these isomers to form β-NAD(P)⁺ and then pass the electrons to dioxygen, forming H₂O₂. We have also shown that these substrate molecules are highly inhibitory to dehydrogenase enzymes and thus have proposed an intracellular metabolic role for this enzyme. Here, we identify a renalase from an organism without a circulatory system. This bacterial form of renalase has the same substrate specificity profile as that of human renalase but, in terms of binding constant (K(d)), shows a marked preference for substrates derived from β-NAD⁺. 2-dihydroNAD(P) substrates reduce the enzyme with rate constants (k(red)) that greatly exceed those for 6-dihydroNAD(P) substrates. Taken together, k(red)/K(d) values indicate a minimum 20-fold preference for 2DHNAD. We also offer the first structures of a renalase in complex with catalytically relevant ligands β-NAD⁺ and β-NADH (the latter being an analogue of the substrate(s)). These structures show potential electrostatic repulsion interactions with the product and a unique binding orientation for the substrate nicotinamide base that is consistent with the identified activity.
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Affiliation(s)
- Matthew R Hoag
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, 3210 North Cramer Street, Milwaukee, Wisconsin 53211-3209, United States
| | - Joseph Roman
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, 3210 North Cramer Street, Milwaukee, Wisconsin 53211-3209, United States
| | - Brett A Beaupre
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, 3210 North Cramer Street, Milwaukee, Wisconsin 53211-3209, United States
| | - Nicholas R Silvaggi
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, 3210 North Cramer Street, Milwaukee, Wisconsin 53211-3209, United States
| | - Graham R Moran
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, 3210 North Cramer Street, Milwaukee, Wisconsin 53211-3209, United States
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The catalytic function of renalase: A decade of phantoms. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2015; 1864:177-86. [PMID: 25900362 DOI: 10.1016/j.bbapap.2015.04.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Revised: 04/08/2015] [Accepted: 04/10/2015] [Indexed: 12/31/2022]
Abstract
Ten years after the initial identification of human renalase the first genuinely catalytic substrates have been identified. Throughout the prior decade a consensus belief that renalase is produced predominantly by the kidney and catalytically oxidizes catecholamines in order to lower blood pressure and slow the heart has prevailed. This belief was, however, based on fundamentally flawed scientific observations that did not include control reactions to account for the well-known autoxidation of catecholamines in oxygenated solutions. Nonetheless, the initial claims have served as the kernel for a rapidly expanding body of research largely predicated on the belief that catecholamines are substrates for this enzyme. The proliferation of scientific studies pertaining to renalase as a hormone has proceeded unabated despite well-reasoned expressions of dissent that have indicated the deficiencies of the initial observations and other inconsistencies. Our group has very recently identified isomeric forms of β-NAD(P)H as substrates for renalase. These substrates arise from non-specific reduction of β-NAD(P)(+) that forms β-4-dihydroNAD(P) (β-NAD(P)H), β-2-dihydroNAD(P) and β-6-dihydroNAD(P); the latter two being substrates for renalase. Renalase oxidizes these substrates with rate constants that are up to 10(4)-fold faster than any claimed for catecholamines. The electrons harvested are delivered to dioxygen via the enzyme's FAD cofactor forming both H2O2 and β-NAD(P)(+) as products. It would appear that the metabolic purpose of this chemistry is to alleviate the inhibitory effect of β-2-dihydroNAD(P) and β-6-dihydroNAD(P) on primary metabolism dehydrogenase enzymes. The identification of this genuinely catalytic activity for renalase calls for re-evaluation of much of the research of this enzyme, in which definitive links between renalase catecholamine consumption and physiological responses were reported. This article is part of a Special Issue entitled: Physiological enzymology and protein functions.
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Jensen CN, Mielke T, Farrugia JE, Frank A, Man H, Hart S, Turkenburg JP, Grogan G. Structures of the Apo and FAD-bound forms of 2-hydroxybiphenyl 3-monooxygenase (HbpA) locate activity hotspots identified by using directed evolution. Chembiochem 2015; 16:968-76. [PMID: 25737306 PMCID: PMC4515095 DOI: 10.1002/cbic.201402701] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Indexed: 11/09/2022]
Abstract
The FAD-dependent monooxygenase HbpA from Pseudomonas azelaica HBP1 catalyses the hydroxylation of 2-hydroxybiphenyl (2HBP) to 2,3-dihydroxybiphenyl (23DHBP). HbpA has been used extensively as a model for studying flavoprotein hydroxylases under process conditions, and has also been subjected to directed-evolution experiments that altered its catalytic properties. The structure of HbpA has been determined in its apo and FAD-complex forms to resolutions of 2.76 and 2.03 Å, respectively. Comparisons of the HbpA structure with those of homologues, in conjunction with a model of the reaction product in the active site, reveal His48 as the most likely acid/base residue to be involved in the hydroxylation mechanism. Mutation of His48 to Ala resulted in an inactive enzyme. The structures of HbpA also provide evidence that mutants achieved by directed evolution that altered activity are comparatively remote from the substrate-binding site.
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Affiliation(s)
- Chantel N Jensen
- York Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York, YO10 5DD (UK)
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Long Y, Yang S, Xie Z, Cheng L. Identification and characterization of phenol hydroxylase from phenol-degrading Candida tropicalis strain JH8. Can J Microbiol 2014; 60:585-91. [DOI: 10.1139/cjm-2014-0417] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The gene phhY encoding phenol hydroxylase from Candida tropicalis JH8 was cloned, sequenced, and expressed in Escherichia coli. The gene phhY contained an open reading frame of 2130 bp encoding a polypeptide of 709 amino acid residues. From its sequence analysis, it is a member of a family of flavin-containing aromatic hydroxylases and shares 41% amino acid identity with phenol hydroxylase from Trichosporon cutaneum. The recombinant phenol hydroxylase exists as a homotetramer structure with a native molecular mass of 320 kDa. Recombinant phenol hydroxylase was insensitive to pH treatment; its optimum pH was at 7.6. The optimum temperature for the enzyme was 30 °C, and its activity was rapidly lost at temperatures above 60 °C. Under the optimal conditions with phenol as substrate, the Km and Vmax of recombinant phenol hydroxylase were 0.21 mmol·L–1 and 0.077 μmol·L–1·min−1, respectively. This is the first paper presenting the cloning and expression in E. coli of the phenol hydroxylase gene from C. tropicalis and the characterization of the recombinant phenol hydroxylase.
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Affiliation(s)
- Yan Long
- College of Life Sciences, Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), State Key Laboratory of Virology, Wuhan University, Wuhan 430072, People’s Republic of China
- Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, Wuhan 430072, People’s Republic of China
| | - Sheng Yang
- College of Life Sciences, Hubei University, Wuhan 430062, People’s Republic of China
| | - Zhixiong Xie
- College of Life Sciences, Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), State Key Laboratory of Virology, Wuhan University, Wuhan 430072, People’s Republic of China
- Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, Wuhan 430072, People’s Republic of China
| | - Li Cheng
- College of Life Sciences, Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), State Key Laboratory of Virology, Wuhan University, Wuhan 430072, People’s Republic of China
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Giridharan SSP, Caplan S. MICAL-family proteins: Complex regulators of the actin cytoskeleton. Antioxid Redox Signal 2014; 20:2059-73. [PMID: 23834433 PMCID: PMC3993057 DOI: 10.1089/ars.2013.5487] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
SIGNIFICANCE The molecules interacting with CasL (MICAL) family members participate in a multitude of activities, including axonal growth cone repulsion, membrane trafficking, apoptosis, and bristle development in flies. An interesting feature of MICAL proteins is the presence of an N-terminal flavo-mono-oxygenase domain. This mono-oxygenase domain generates redox potential with which MICALs can either oxidize proteins or produce reactive oxygen species (ROS). Actin is one such protein that is affected by MICAL function, leading to dramatic cytoskeletal rearrangements. This review describes the MICAL-family members, and discusses their mechanisms of actin-binding and regulation of actin cytoskeleton organization. RECENT ADVANCES Recent studies show that MICALs directly induce oxidation of actin molecules, leading to actin depolymerization. ROS production by MICALs also causes oxidation of collapsin response mediator protein-2, a microtubule assembly promoter, which subsequently undergoes phosphorylation. CRITICAL ISSUES MICAL proteins oxidize proteins through two mechanisms: either directly by oxidizing methionine residues or indirectly via the production of ROS. It remains unclear whether MICAL proteins employ both mechanisms or whether the activity of MICAL-family proteins might vary with different substrates. FUTURE DIRECTIONS The identification of additional substrates oxidized by MICAL will shed new light on MICAL protein function. Additional directions include expanding studies toward the MICAL-like homologs that lack flavin adenine dinucleotide domains and oxidation activity.
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Affiliation(s)
- Sai Srinivas Panapakkam Giridharan
- Department of Biochemistry and Molecular Biology, and the Pamela and Fred Buffett Cancer Center, University of Nebraska Medical Center , Omaha, Nebraska
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Aussel L, Pierrel F, Loiseau L, Lombard M, Fontecave M, Barras F. Biosynthesis and physiology of coenzyme Q in bacteria. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:1004-11. [PMID: 24480387 DOI: 10.1016/j.bbabio.2014.01.015] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 01/23/2014] [Accepted: 01/24/2014] [Indexed: 11/24/2022]
Abstract
Ubiquinone, also called coenzyme Q, is a lipid subject to oxido-reduction cycles. It functions in the respiratory electron transport chain and plays a pivotal role in energy generating processes. In this review, we focus on the biosynthetic pathway and physiological role of ubiquinone in bacteria. We present the studies which, within a period of five decades, led to the identification and characterization of the genes named ubi and involved in ubiquinone production in Escherichia coli. When available, the structures of the corresponding enzymes are shown and their biological function is detailed. The phenotypes observed in mutants deficient in ubiquinone biosynthesis are presented, either in model bacteria or in pathogens. A particular attention is given to the role of ubiquinone in respiration, modulation of two-component activity and bacterial virulence. This article is part of a Special Issue entitled: 18th European Bioenergetic Conference.
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Affiliation(s)
- Laurent Aussel
- Laboratoire de Chimie Bactérienne, UMR 7283 Aix-Marseille Université - CNRS, Institut de Microbiologie de la Méditerranée, 31 Chemin Joseph Aiguier 13009 Marseille, France
| | - Fabien Pierrel
- Laboratoire de Chimie et Biologie des Métaux, UMR 5249 CEA - Université Grenoble I - CNRS, 17 Rue des Martyrs, 38054 Grenoble Cedex France
| | - Laurent Loiseau
- Laboratoire de Chimie Bactérienne, UMR 7283 Aix-Marseille Université - CNRS, Institut de Microbiologie de la Méditerranée, 31 Chemin Joseph Aiguier 13009 Marseille, France
| | - Murielle Lombard
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, UPMC, Collège de France, 11 Place Marcellin Berthelot, 75231 Paris Cedex 05 France
| | - Marc Fontecave
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, UPMC, Collège de France, 11 Place Marcellin Berthelot, 75231 Paris Cedex 05 France
| | - Frédéric Barras
- Laboratoire de Chimie Bactérienne, UMR 7283 Aix-Marseille Université - CNRS, Institut de Microbiologie de la Méditerranée, 31 Chemin Joseph Aiguier 13009 Marseille, France.
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Beaupre BA, Hoag MR, Carmichael BR, Moran GR. Kinetics and equilibria of the reductive and oxidative half-reactions of human renalase with α-NADPH. Biochemistry 2013; 52:8929-37. [PMID: 24266457 DOI: 10.1021/bi401185m] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Renalase is a recently discovered flavoprotein that has been reported to be a hormone produced by the kidney to down-modulate blood pressure and heart rate. The consensus belief has been that renalase oxidizes circulating catecholamine neurotransmitters thereby attenuating vascular tone. However, a convincing in vitro demonstration of this activity has not been made. We have recently discovered that renalase has α-NAD(P)H oxidase/anomerase activity. Unlike most naturally occurring nucleotides, NAD(P)H can accumulate small amounts of the α-anomers that once oxidized are configurationally stable and unable to participate in cellular activity. Thus, anomerization of NAD(P)H would result in a continual loss of cellular redox currency. As such, it appears that the root purpose of renalase is to return α-anomers of nicotinamide dinucleotides to the β-anomer pool. In this article, we measure the kinetics and equilibria of renalase in turnover with α-NADPH. Renalase is selective for the α-anomer, which binds with a dissociation constant of ∼20±3 μM. This association precedes monophasic two-electron reduction of the FAD cofactor with a rate constant of 40.2±1.3 s(-1). The reduced enzyme then delivers both electrons to dioxygen in a second-order reaction with a rate constant of ∼2900 M(-1) s(-1). Renalase has modest affinity for its β-NADP+ product (Kd=2.2 mM), and the FAD cofactor has a reduction potential of -155 mV that is unaltered by saturating β-NADP+. Together these data suggest that the products are formed and released in a kinetically ordered sequence (β-NADP+ then H2O2), however, the reoxidation of renalase is not contingent on the dissociation of β-NADP+. Neither the oxidized nor the reduced form of renalase is able to catalyze anomerization, implying that the redox and anomerization chemistries are inextricably linked through a common intermediate.
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Affiliation(s)
- Brett A Beaupre
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee , 3210 N. Cramer Street, Milwaukee, Wisconsin 53211-3209, United States
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Effect of vanillic acid on COQ6 mutants identified in patients with coenzyme Q10 deficiency. Biochim Biophys Acta Mol Basis Dis 2013; 1842:1-6. [PMID: 24140869 PMCID: PMC3898990 DOI: 10.1016/j.bbadis.2013.10.007] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 10/04/2013] [Accepted: 10/07/2013] [Indexed: 11/20/2022]
Abstract
Human COQ6 encodes a monooxygenase which is responsible for the C5-hydroxylation of the quinone ring of coenzyme Q (CoQ). Mutations in COQ6 cause primary CoQ deficiency, a condition responsive to oral CoQ10 supplementation. Treatment is however still problematic given the poor bioavailability of CoQ10. We employed S. cerevisiae lacking the orthologous gene to characterize the two different human COQ6 isoforms and the mutations found in patients. COQ6 isoform a can partially complement the defective yeast, while isoform b, which lacks part of the FAD-binding domain, is inactive but partially stable, and could have a regulatory/inhibitory function in CoQ10 biosynthesis. Most mutations identified in patients, including the frameshift Q461fs478X mutation, retain residual enzymatic activity, and all patients carry at least one hypomorphic allele, confirming that the complete block of CoQ biosynthesis is lethal. These mutants are also partially stable and allow the assembly of the CoQ biosynthetic complex. In fact treatment with two hydroxylated analogues of 4-hydroxybenzoic acid, namely, vanillic acid or 3-4-hydroxybenzoic acid, restored the respiratory growth of yeast Δcoq6 cells expressing the mutant huCOQ6-isoa proteins. These compounds, and particularly vanillic acid, could therefore represent an interesting therapeutic option for COQ6 patients.
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Sucharitakul J, Tongsook C, Pakotiprapha D, van Berkel WJH, Chaiyen P. The reaction kinetics of 3-hydroxybenzoate 6-hydroxylase from Rhodococcus jostii RHA1 provide an understanding of the para-hydroxylation enzyme catalytic cycle. J Biol Chem 2013; 288:35210-21. [PMID: 24129570 DOI: 10.1074/jbc.m113.515205] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
3-Hydroxybenzoate 6-hydroxylase (3HB6H) from Rhodococcus jostii RHA1 is an NADH-specific flavoprotein monooxygenase that catalyzes the para-hydroxylation of 3-hydroxybenzoate (3HB) to form 2,5-dihydroxybenzoate (2,5-DHB). Based on results from stopped-flow spectrophotometry, the reduced enzyme-3HB complex reacts with oxygen to form a C4a-peroxy flavin with a rate constant of 1.13 ± 0.01 × 10(6) m(-1) s(-1) (pH 8.0, 4 °C). This intermediate is subsequently protonated to form a C4a-hydroperoxyflavin with a rate constant of 96 ± 3 s(-1). This step shows a solvent kinetic isotope effect of 1.7. Based on rapid-quench measurements, the hydroxylation occurs with a rate constant of 36 ± 2 s(-1). 3HB6H does not exhibit substrate inhibition on the flavin oxidation step, a common characteristic found in most ortho-hydroxylation enzymes. The apparent kcat at saturating concentrations of 3HB, NADH, and oxygen is 6.49 ± 0.02 s(-1). Pre-steady state and steady-state kinetic data were used to construct the catalytic cycle of the reaction. The data indicate that the steps of product release (11.7 s(-1)) and hydroxylation (36 ± 2 s(-1)) partially control the overall turnover.
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Affiliation(s)
- Jeerus Sucharitakul
- From the Department of Biochemistry, Faculty of Dentistry, Chulalongkorn University, Henri Dunant Road, Patumwan, Bangkok 10330, Thailand
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42
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Beaupre BA, Carmichael BR, Hoag MR, Shah DD, Moran GR. Renalase is an α-NAD(P)H oxidase/anomerase. J Am Chem Soc 2013; 135:13980-7. [PMID: 23964689 DOI: 10.1021/ja407384h] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Renalase is a protein hormone secreted into the blood by the kidney that is reported to lower blood pressure and slow heart rate. Since its discovery in 2005, renalase has been the subject of conjecture pertaining to its catalytic function. While it has been widely reported that renalase is the third monoamine oxidase (monoamine oxidase C) that oxidizes circulating catecholamines such as epinephrine, there has been no convincing demonstration of this catalysis in vitro. Renalase is a flavoprotein whose structural topology is similar to known oxidases, lysine demethylases, and monooxygenases, but its active site bears no resemblance to that of any known flavoprotein. We have identified the catalytic activity of renalase as an α-NAD(P)H oxidase/anomerase, whereby low equilibrium concentrations of the α-anomer of NADPH and NADH initiate rapid reduction of the renalase flavin cofactor. The reduced cofactor then reacts with dioxygen to form hydrogen peroxide and releases nicotinamide dinucleotide product in the β-form. These processes yield an apparent turnover number (0.5 s(-1) in atmospheric dioxygen) that is at least 2 orders of magnitude more rapid than any reported activity with catechol neurotransmitters. This highly novel activity is the first demonstration of a role for naturally occurring α-NAD(P)H anomers in mammalian physiology and the first report of a flavoprotein catalyzing an epimerization reaction.
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Affiliation(s)
- Brett A Beaupre
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee , 3210 N. Cramer Street, Milwaukee, Wisconsin 53211-3209, United States
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43
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Montersino S, Orru R, Barendregt A, Westphal AH, van Duijn E, Mattevi A, van Berkel WJH. Crystal structure of 3-hydroxybenzoate 6-hydroxylase uncovers lipid-assisted flavoprotein strategy for regioselective aromatic hydroxylation. J Biol Chem 2013; 288:26235-26245. [PMID: 23864660 DOI: 10.1074/jbc.m113.479303] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
3-Hydroxybenzoate 6-hydroxylase (3HB6H) from Rhodococcus jostii RHA1 is a dimeric flavoprotein that catalyzes the NADH- and oxygen-dependent para-hydroxylation of 3-hydroxybenzoate to 2,5-dihydroxybenzoate. In this study, we report the crystal structure of 3HB6H as expressed in Escherichia coli. The overall fold of 3HB6H is similar to that of p-hydroxybenzoate hydroxylase and other flavoprotein aromatic hydroxylases. Unexpectedly, a lipid ligand is bound to each 3HB6H monomer. Mass spectral analysis identified the ligand as a mixture of phosphatidylglycerol and phosphatidylethanolamine. The fatty acid chains occupy hydrophobic channels that deeply penetrate into the interior of the substrate-binding domain of each subunit, whereas the hydrophilic part is exposed on the protein surface, connecting the dimerization domains via a few interactions. Most remarkably, the terminal part of a phospholipid acyl chain is directly involved in the substrate-binding site. Co-crystallized chloride ion and the crystal structure of the H213S variant with bound 3-hydroxybenzoate provide hints about oxygen activation and substrate hydroxylation. Essential roles are played by His-213 in catalysis and Tyr-105 in substrate binding. This phospholipid-assisted strategy to control regioselective aromatic hydroxylation is of relevance for optimization of flavin-dependent biocatalysts.
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Affiliation(s)
- Stefania Montersino
- From the Laboratory of Biochemistry, Wageningen University, 6703 HA Wageningen, The Netherlands
| | - Roberto Orru
- Department of Biology and Biotechnology, University of Pavia, Via Ferrata 9, 27100 Pavia, Italy, and
| | - Arjan Barendregt
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research, and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Adrie H Westphal
- From the Laboratory of Biochemistry, Wageningen University, 6703 HA Wageningen, The Netherlands
| | - Esther van Duijn
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research, and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Andrea Mattevi
- Department of Biology and Biotechnology, University of Pavia, Via Ferrata 9, 27100 Pavia, Italy, and.
| | - Willem J H van Berkel
- From the Laboratory of Biochemistry, Wageningen University, 6703 HA Wageningen, The Netherlands,.
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Kallio P, Patrikainen P, Belogurov GA, Mäntsälä P, Yang K, Niemi J, Metsä-Ketelä M. Tracing the evolution of angucyclinone monooxygenases: structural determinants for C-12b hydroxylation and substrate inhibition in PgaE. Biochemistry 2013; 52:4507-16. [PMID: 23731237 DOI: 10.1021/bi400381s] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Two functionally distinct homologous flavoprotein hydroxylases, PgaE and JadH, have been identified as branching points in the biosynthesis of the polyketide antibiotics gaudimycin C and jadomycin A, respectively. These evolutionarily related enzymes are both bifunctional and able to catalyze the same initial reaction, C-12 hydroxylation of the common angucyclinone intermediate prejadomycin. The enzymes diverge in their secondary activities, which include hydroxylation at C-12b by PgaE and dehydration at C-4a/C-12b by JadH. A further difference is that the C-12 hydroxylation is subject to substrate inhibition only in PgaE. Here we have identified regions associated with the C-12b hydroxylation in PgaE by extensive chimeragenesis, focusing on regions surrounding the active site. The results highlight the importance of a hairpin-β motif near the dimer interface, with two nonconserved residues, P78 and I79 (corresponding to Q89 and F90, respectively, in JadH), and invariant residue H73 playing key roles. Kinetic characterization of PgaE variants demonstrates that the secondary C-12b hydroxylation and substrate inhibition by prejadomycin are likely to be interlinked. The crystal structure of the PgaE P78Q/I79F variant at 2.4 Å resolution confirms that the changes do not alter the conformation of the β-strand secondary structure and that the side chains of these residues in effect point away from the active site toward the dimer interface. The results support a catalytic model for PgaE containing two binding modes for C-12 and C-12b hydroxylations, where binding of prejadomycin in the orientation for C-12b hydroxylation leads to substrate inhibition. The presence of an allosteric network is evident based on enzyme kinetics.
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Affiliation(s)
- Pauli Kallio
- Department of Biochemistry and Food Chemistry, University of Turku, FIN-20014 Turku, Finland
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45
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Suemori A. Conserved and non-conserved residues and their role in the structure and function of p-hydroxybenzoate hydroxylase. Protein Eng Des Sel 2013; 26:479-88. [PMID: 23766373 DOI: 10.1093/protein/gzt026] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In order to elucidate the molecular mechanism of the catalytic reaction and enzyme conformation, we substituted 53 conserved residues identified by aligning 92 p-hydroxybenzoate hydroxylase sequences and 19 non-conserved residues selected from crystallographic studies of Pseudomonas fluorescens NBRC14160 p-hydroxybenzoate hydroxylase with 19 other naturally occurring amino acids, yielding a database of 619 active single mutants. The database contained 365 and 254 active single mutants for 44/53 conserved residues and 19 non-conserved residues, respectively; the data included main activity, sub-activity for NADPH and NADPH reaction specificity. Active mutations were not observed for the G14, Q102, G160, E198, R220, R246, N300, F342 and G387 conserved residues, and only one active mutant was obtained at the G9, G11, G187, D286, Y201, R214 and G295 conserved residues and the S13, E32 and R42 non-conserved residues. Only seven active mutants with higher activity than the wild-type enzyme were observed at conserved residues, and only two were observed at non-conserved residues. The 365 mutants at conserved residues included 64 active mutants with higher NADPH reaction specificity than the wild-type enzyme, and some Y181X single mutants exhibited considerable changes in NADPH reaction specificity. A Y181X/L268G double-mutant database was constructed to computationally analyze the effects of these substitutions on structural conformation and function. These results indicated that some conserved or non-conserved residues are important for structural stability or enzyme function.
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Affiliation(s)
- Akio Suemori
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology-AIST, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan.
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Hajj Chehade M, Loiseau L, Lombard M, Pecqueur L, Ismail A, Smadja M, Golinelli-Pimpaneau B, Mellot-Draznieks C, Hamelin O, Aussel L, Kieffer-Jaquinod S, Labessan N, Barras F, Fontecave M, Pierrel F. ubiI, a new gene in Escherichia coli coenzyme Q biosynthesis, is involved in aerobic C5-hydroxylation. J Biol Chem 2013; 288:20085-92. [PMID: 23709220 DOI: 10.1074/jbc.m113.480368] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Coenzyme Q (ubiquinone or Q) is a redox-active lipid found in organisms ranging from bacteria to mammals in which it plays a crucial role in energy-generating processes. Q biosynthesis is a complex pathway that involves multiple proteins. In this work, we show that the uncharacterized conserved visC gene is involved in Q biosynthesis in Escherichia coli, and we have renamed it ubiI. Based on genetic and biochemical experiments, we establish that the UbiI protein functions in the C5-hydroxylation reaction. A strain deficient in ubiI has a low level of Q and accumulates a compound derived from the Q biosynthetic pathway, which we purified and characterized. We also demonstrate that UbiI is only implicated in aerobic Q biosynthesis and that an alternative enzyme catalyzes the C5-hydroxylation reaction in the absence of oxygen. We have solved the crystal structure of a truncated form of UbiI. This structure shares many features with the canonical FAD-dependent para-hydroxybenzoate hydroxylase and represents the first structural characterization of a monooxygenase involved in Q biosynthesis. Site-directed mutagenesis confirms that residues of the flavin binding pocket of UbiI are important for activity. With our identification of UbiI, the three monooxygenases necessary for aerobic Q biosynthesis in E. coli are known.
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Affiliation(s)
- Mahmoud Hajj Chehade
- Commissariat à l'Energie Atomique, Institut de Recherches en Technologies et Sciences pour le Vivant, Laboratoire Chimie et Biologie des Métaux, F-38054 Grenoble, France
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MICAL, the flavoenzyme participating in cytoskeleton dynamics. Int J Mol Sci 2013; 14:6920-59. [PMID: 23535333 PMCID: PMC3645671 DOI: 10.3390/ijms14046920] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 03/02/2013] [Accepted: 03/11/2013] [Indexed: 01/01/2023] Open
Abstract
MICAL (from the Molecule Interacting with CasL) indicates a family of recently discovered cytosolic, multidomain proteins, which uniquely couple an N-terminal FAD-containing monooxygenase-like domain to typical calponine homology, LIM and coiled-coil protein-interaction modules. Genetic and cell biology approaches have demonstrated an essential role of the catalytic activity of the monooxygenase-like domain in transducing the signal initiated by semaphorins interaction with their plexin receptors, which results in local actin cytoskeleton disassembly as part of fundamental processes that include differentiation, migration and cell-cell contacts in neuronal and non-neuronal cell types. This review focuses on the structure-function relations of the MICAL monooxygenase-like domain as they are emerging from the available in vitro studies on mouse, human and Drosophila MICAL forms that demonstrated a NADPH-dependent actin depolymerizing activity of MICAL. With Drosophila MICAL forms, actin depolymerization was demonstrated to be associated to conversion of Met44 to methionine sulfone through a postulated hydroxylating reaction. Arguments supporting the concept that MICAL effect on F-actin may be reversible will be discussed.
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Form follows function: structural and catalytic variation in the class a flavoprotein monooxygenases. Int J Mol Sci 2012; 13:15601-39. [PMID: 23443084 PMCID: PMC3546652 DOI: 10.3390/ijms131215601] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Revised: 11/08/2012] [Accepted: 11/09/2012] [Indexed: 12/02/2022] Open
Abstract
Flavoprotein monooxygenases (FPMOs) exhibit an array of mechanistic solutions to a common chemical objective; the monooxygenation of a target substrate. Each FPMO efficiently couples reduction of a flavin cofactor by NAD(P)H to oxygenation of the target substrate via a (hydro)peroxyflavin intermediate. This purpose of this review is to describe in detail the Class A flavoprotein hydroxylases (FPMO) in the context of the other FPMO classes (B–F). Both one and two component FPMOs are found in nature. Two-component enzymes require, in addition to the monooxygenase, the involvement of a reductase that first catalyzes the reduction of the flavin by NAD(P)H. The Class A and B FPMOs are single-component and manage to orchestrate the same net reaction within a single peptide. The Class A enzymes have, by some considerable margin, the most complete research record. These enzymes use choreographed movements of the flavin ring that facilitate access of the organic substrates to the active site, provide a means for interaction of NADPH with the flavin, offer a mechanism to sequester the dioxygen reduction chemistry from solvent and a means to release the product. The majority of the discrete catalytic events of the catalytic cycle can be observed directly in exquisite detail using spectrophotometric kinetic methods and many of the key mechanistic conclusions are further supported by structural data. This review attempts to compile each of the key observations made for both paradigm and newly discovered examples of Class A FPMOs into a complete catalytic description of one enzymatic turnover.
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Yachnin BJ, Sprules T, McEvoy MB, Lau PCK, Berghuis AM. The substrate-bound crystal structure of a Baeyer-Villiger monooxygenase exhibits a Criegee-like conformation. J Am Chem Soc 2012; 134:7788-95. [PMID: 22506764 PMCID: PMC3349289 DOI: 10.1021/ja211876p] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
The Baeyer–Villiger monooxygenases (BVMOs) are
a family of bacterial flavoproteins that catalyze the synthetically
useful Baeyer–Villiger oxidation reaction. This involves the
conversion of ketones into esters or cyclic ketones into lactones
by introducing an oxygen atom adjacent to the carbonyl group. The
BVMOs offer exquisite regio- and enantiospecificity while acting on
a wide range of substrates. They use only NADPH and oxygen as cosubstrates,
and produce only NADP+ and water as byproducts, making
them environmentally attractive for industrial purposes. Here, we
report the first crystal structure of a BVMO, cyclohexanone monooxygenase
(CHMO) from Rhodococcus sp. HI-31 in complex with
its substrate, cyclohexanone, as well as NADP+ and FAD,
to 2.4 Å resolution. This structure shows a drastic rotation
of the NADP+ cofactor in comparison to previously reported
NADP+-bound structures, as the nicotinamide moiety is no
longer positioned above the flavin ring. Instead, the substrate, cyclohexanone,
is found at this location, in an appropriate position for the formation
of the Criegee intermediate. The rotation of NADP+ permits
the substrate to gain access to the reactive flavin peroxyanion intermediate
while preventing it from diffusing out of the active site. The structure
thus reveals the conformation of the enzyme during the key catalytic
step. CHMO is proposed to undergo a series of conformational changes
to gradually move the substrate from the solvent, via binding in a
solvent excluded pocket that dictates the enzyme’s chemospecificity,
to a location above the flavin–peroxide adduct where catalysis
occurs.
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Affiliation(s)
- Brahm J Yachnin
- Department of Biochemistry, McGill University, 3649 Promenade Sir William Osler, Bellini Pavilion, Room 466, Montreal, QC, Canada H3G 0B1
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50
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Belter A, Skupinska M, Giel-Pietraszuk M, Grabarkiewicz T, Rychlewski L, Barciszewski J. Squalene monooxygenase – a target for hypercholesterolemic therapy. Biol Chem 2011; 392:1053-75. [DOI: 10.1515/bc.2011.195] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Abstract
Squalene monooxygenase catalyzes the epoxidation of C-C double bond of squalene to yield 2,3-oxidosqualene, the key step of sterol biosynthesis pathways in eukaryotes. Sterols are essential compounds of these organisms and squalene epoxidation is an important regulatory point in their synthesis. Squalene monooxygenase downregulation in vertebrates and fungi decreases synthesis of cholesterol and ergosterol, respectively, which makes squalene monooxygenase a potent and attractive target of hypercholesterolemia and antifungal therapies. Currently some fungal squalene monooxygenase inhibitors (terbinafine, naftifine, butenafine) are in clinical use, whereas mammalian enzymes’ inhibitors are still under investigation. Research on new squalene monooxygenase inhibitors is important due to the prevalence of hypercholesterolemia and the lack of both sufficient and safe remedies. In this paper we (i) review data on activity and the structure of squalene monooxygenase, (ii) present its inhibitors, (iii) compare current strategies of lowering cholesterol level in blood with some of the most promising strategies, (iv) underline advantages of squalene monooxygenase as a target for hypercholesterolemia therapy, and (v) discuss safety concerns about hypercholesterolemia therapy based on inhibition of cellular cholesterol biosynthesis and potential usage of squalene monooxygenase inhibitors in clinical practice. After many years of use of statins there is some clinical evidence for their adverse effects and only partial effectiveness. Currently they are drugs of choice but are used with many restrictions, especially in case of children, elderly patients and women of childbearing potential. Certainly, for the next few years, statins will continue to be a suitable tool for cost-effective cardiovascular prevention; however research on new hypolipidemic drugs is highly desirable. We suggest that squalene monooxygenase inhibitors could become the hypocholesterolemic agents of the future.
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