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Dinh MTN, Nguyen VT, Nguyen LTH. The potential application of carbazole-degrading bacteria for dioxin bioremediation. BIORESOUR BIOPROCESS 2023; 10:56. [PMID: 38647625 PMCID: PMC10992316 DOI: 10.1186/s40643-023-00680-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 08/17/2023] [Indexed: 04/25/2024] Open
Abstract
Extensive research has been conducted over the years on the bacterial degradation of dioxins and their related compounds including carbazole, because these chemicals are highly toxic and has been widely distributed in the environment. There is a pressing need to explore and develop more bacterial strains with unique catabolic features to effectively remediate dioxin-polluted sites. Carbazole has a chemical structure similar to dioxins, and the degradation pathways of these two chemicals are highly homologous. Some carbazole-degrading bacterial strains have been demonstrated to have the ability to degrade dioxins, such as Pseudomonas sp. strain CA10 và Sphingomonas sp. KA1. The introduction of strain KA1 into dioxin-contaminated model soil resulted in the degradation of 96% and 70% of 2-chlorodibenzo-p-dioxin (2-CDD) and 2,3-dichlorodibenzo-p-dioxin (2,3-DCDD), respectively, after 7-day incubation period. These degradation rates were similar to those achieved with strain CA10, which removed 96% of 2-CDD and 80% of 2,3-DCDD from the same model soil. Therefore, carbazole-degrading bacteria hold significant promise as potential candidates for dioxin bioremediation. This paper overviews the connection between the bacterial degradation of dioxins and carbazole, highlighting the potential for dioxin biodegradation by carbazole-degrading bacterial strains.
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Affiliation(s)
- Mai Thi Ngoc Dinh
- Faculty of Biotechnology, Chemistry and Environmental Engineering, Phenikaa University, A9 Building, Nguyen Van Trac Street, Ha Dong District, Hanoi, Vietnam.
- Bioresource Research Center, Phenikaa University, Hanoi, Vietnam.
| | - Van Thi Nguyen
- VNU Institute of Microbiology and Biotechnology, Vietnam National University, E2 Building, 144 Xuan Thuy Street, Cau Giay District, Hanoi, Vietnam
| | - Ly Thi Huong Nguyen
- Department of Physiology, College of Korean Medicine, Dongguk University, Gyeongju, Republic of Korea
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Runda ME, de Kok NAW, Schmidt S. Rieske Oxygenases and Other Ferredoxin-Dependent Enzymes: Electron Transfer Principles and Catalytic Capabilities. Chembiochem 2023; 24:e202300078. [PMID: 36964978 DOI: 10.1002/cbic.202300078] [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: 01/31/2023] [Revised: 03/24/2023] [Accepted: 03/24/2023] [Indexed: 03/27/2023]
Abstract
Enzymes that depend on sophisticated electron transfer via ferredoxins (Fds) exhibit outstanding catalytic capabilities, but despite decades of research, many of them are still not well understood or exploited for synthetic applications. This review aims to provide a general overview of the most important Fd-dependent enzymes and the electron transfer processes involved. While several examples are discussed, we focus in particular on the family of Rieske non-heme iron-dependent oxygenases (ROs). In addition to illustrating their electron transfer principles and catalytic potential, the current state of knowledge on structure-function relationships and the mode of interaction between the redox partner proteins is reviewed. Moreover, we highlight several key catalyzed transformations, but also take a deeper dive into their engineerability for biocatalytic applications. The overall findings from these case studies highlight the catalytic capabilities of these biocatalysts and could stimulate future interest in developing additional Fd-dependent enzyme classes for synthetic applications.
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Affiliation(s)
- Michael E Runda
- Department of Chemical and Pharmaceutical Biology, Groningen Research Institute of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands
| | - Niels A W de Kok
- Department of Chemical and Pharmaceutical Biology, Groningen Research Institute of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands
| | - Sandy Schmidt
- Department of Chemical and Pharmaceutical Biology, Groningen Research Institute of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands
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3
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Ashikawa Y, Fujimoto Z, Inoue K, Yamane H, Nojiri H. Crystal structure of the ferredoxin reductase component of carbazole 1,9a-dioxygenase from Janthinobacterium sp. J3. Acta Crystallogr D Struct Biol 2021; 77:921-932. [PMID: 34196618 PMCID: PMC8251347 DOI: 10.1107/s2059798321005040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 05/12/2021] [Indexed: 11/17/2022] Open
Abstract
Carbazole 1,9a-dioxygenase (CARDO), which consists of an oxygenase component and the electron-transport components ferredoxin (CARDO-F) and ferredoxin reductase (CARDO-R), is a Rieske nonheme iron oxygenase (RO). ROs are classified into five subclasses (IA, IB, IIA, IIB and III) based on their number of constituents and the nature of their redox centres. In this study, two types of crystal structure (type I and type II) were resolved of the class III CARDO-R from Janthinobacterium sp. J3 (CARDO-RJ3). Superimposition of the type I and type II structures revealed the absence of flavin adenine dinucleotide (FAD) in the type II structure along with significant conformational changes to the FAD-binding domain and the C-terminus, including movements to fill the space in which FAD had been located. Docking simulation of NADH into the FAD-bound form of CARDO-RJ3 suggested that shifts of the residues at the C-terminus caused the nicotinamide moiety to approach the N5 atom of FAD, which might facilitate electron transfer between the redox centres. Differences in domain arrangement were found compared with RO reductases from the ferredoxin-NADP reductase family, suggesting that these differences correspond to differences in the structures of their redox partners ferredoxin and terminal oxygenase. The results of docking simulations with the redox partner class III CARDO-F from Pseudomonas resinovorans CA10 suggested that complex formation suitable for efficient electron transfer is stabilized by electrostatic attraction and complementary shapes of the interacting regions.
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Affiliation(s)
- Yuji Ashikawa
- Agro-Biotechnology Research Center, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Zui Fujimoto
- Advanced Analysis Center, National Agriculture and Food Research Organization, 2-1-2 Kannondai, Tsukuba, Ibaraki 305-8518, Japan
| | - Kengo Inoue
- Department of Biochemistry and Applied Biosciences, Faculty of Agriculture, University of Miyazaki, 1-1 Gakuenkibanadai-nishi, Miyazaki 889-2192, Japan
| | - Hisakazu Yamane
- Agro-Biotechnology Research Center, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Hideaki Nojiri
- Agro-Biotechnology Research Center, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
- Agricultural Bioinformatics Research Unit, Graduate School of Agricultural and Life Science, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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Rogers MS, Lipscomb JD. Salicylate 5-Hydroxylase: Intermediates in Aromatic Hydroxylation by a Rieske Monooxygenase. Biochemistry 2019; 58:5305-5319. [PMID: 31066545 PMCID: PMC6856394 DOI: 10.1021/acs.biochem.9b00292] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Rieske oxygenases (ROs) catalyze a large range of oxidative chemistry. We have shown that cis-dihydrodiol-forming Rieske dioxygenases first react with their aromatic substrates via an active site nonheme Fe(III)-superoxide; electron transfer from the Rieske cluster then completes the product-forming reaction. Alternatively, two-electron-reduced Fe(III)-peroxo or hydroxo-Fe(V)-oxo activated oxygen intermediates are possible and may be utilized by other ROs to expand the catalytic range. Here, the reaction of a Rieske monooxygenase, salicylate 5-hydroxylase, that does not form a cis-dihydrodiol is examined. Single-turnover kinetic studies show fast binding of salicylate and O2. Transfer of the Rieske electron required to form the gentisate product occurs through bonds over ∼12 Å and must also be very fast. However, the observed rate constant for this reaction is much slower than expected and sensitive to substrate type. This suggests that initial reaction with salicylate occurs using the same Fe(III)-superoxo-level intermediate as Rieske dioxygenases and that this reaction limits the observed rate of electron transfer. A transient intermediate (λmax = 700 nm) with an electron paramagnetic resonance (EPR) at g = 4.3 is observed after the product is formed in the active site. The use of 17O2 (I = 5/2) results in hyperfine broadening of the g = 4.3 signal, showing that gentisate binds to the mononuclear iron via its C5-OH in the intermediate. The chromophore and EPR signal allow study of product release in the catalytic cycle. Comparison of the kinetics of single- and multiple-turnover reactions shows that re-reduction of the metal centers accelerates product release ∼300-fold, providing insight into the regulatory mechanism of ROs.
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Affiliation(s)
- Melanie S. Rogers
- Department of Biochemistry, Molecular Biology, and Biophysics and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - John D. Lipscomb
- Department of Biochemistry, Molecular Biology, and Biophysics and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, Minnesota 55455, United States
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Electron Transport in a Dioxygenase-Ferredoxin Complex: Long Range Charge Coupling between the Rieske and Non-Heme Iron Center. PLoS One 2016; 11:e0162031. [PMID: 27656882 PMCID: PMC5033481 DOI: 10.1371/journal.pone.0162031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2016] [Accepted: 08/16/2016] [Indexed: 11/19/2022] Open
Abstract
Dioxygenase (dOx) utilizes stereospecific oxidation on aromatic molecules; consequently, dOx has potential applications in bioremediation and stereospecific oxidation synthesis. The reactive components of dOx comprise a Rieske structure Cys2[2Fe-2S]His2 and a non-heme reactive oxygen center (ROC). Between the Rieske structure and the ROC, a universally conserved Asp residue appears to bridge the two structures forming a Rieske-Asp-ROC triad, where the Asp is known to be essential for electron transfer processes. The Rieske and ROC share hydrogen bonds with Asp through their His ligands; suggesting an ideal network for electron transfer via the carboxyl side chain of Asp. Associated with the dOx is an itinerant charge carrying protein Ferredoxin (Fdx). Depending on the specific cognate, Fdx may also possess either the Rieske structure or a related structure known as 4-Cys-[2Fe-2S] (4-Cys). In this study, we extensively explore, at different levels of theory, the behavior of the individual components (Rieske and ROC) and their interaction together via the Asp using a variety of density function methods, basis sets, and a method known as Generalized Ionic Fragment Approach (GIFA) that permits setting up spin configurations manually. We also report results on the 4-Cys structure for comparison. The individual optimized structures are compared with observed spectroscopic data from the Rieske, 4-Cys and ROC structures (where information is available). The separate pieces are then combined together into a large Rieske-Asp-ROC (donor/bridge/acceptor) complex to estimate the overall coupling between individual components, based on changes to the partial charges. The results suggest that the partial charges are significantly altered when Asp bridges the Rieske and the ROC; hence, long range coupling through hydrogen bonding effects via the intercalated Asp bridge can drastically affect the partial charge distributions compared to the individual isolated structures. The results are consistent with a proton coupled electron transfer mechanism.
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Matsuzawa J, Aikawa H, Umeda T, Ashikawa Y, Suzuki-Minakuchi C, Kawano Y, Fujimoto Z, Okada K, Yamane H, Nojiri H. Crystallization and preliminary X-ray diffraction analyses of the redox-controlled complex of terminal oxygenase and ferredoxin components in the Rieske nonhaem iron oxygenase carbazole 1,9a-dioxygenase. Acta Crystallogr F Struct Biol Commun 2014; 70:1406-9. [PMID: 25286950 PMCID: PMC4188090 DOI: 10.1107/s2053230x14018779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 08/18/2014] [Indexed: 11/23/2022] Open
Abstract
The initial reaction in bacterial carbazole degradation is catalyzed by carbazole 1,9a-dioxygenase, which consists of terminal oxygenase (Oxy), ferredoxin (Fd) and ferredoxin reductase components. The electron-transfer complex between reduced Oxy and oxidized Fd was crystallized at 293 K using the hanging-drop vapour-diffusion method with PEG 3350 as the precipitant under anaerobic conditions. The crystal diffracted to a maximum resolution of 2.25 Å and belonged to space group P21, with unit-cell parameters a = 97.3, b = 81.6, c = 116.2 Å, α = γ = 90, β = 100.1°. The VM value is 2.85 Å(3) Da(-1), indicating a solvent content of 56.8%.
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Affiliation(s)
- Jun Matsuzawa
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Hiroki Aikawa
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Takashi Umeda
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Yuji Ashikawa
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Chiho Suzuki-Minakuchi
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Yoshiaki Kawano
- SR Life Science Instrumentation Unit, Research Infrastructure Group, Advanced Photon Technology Division, RIKEN SPring-8 Center, RIKEN Harima Branch, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Zui Fujimoto
- Biomolecular Research Unit, National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602, Japan
| | - Kazunori Okada
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Hisakazu Yamane
- Department of Biosciences, Teikyo University, 1-1 Toyosatodai, Utsunomiya, Tochigi 320-0003, Japan
| | - Hideaki Nojiri
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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Structural basis of the divergent oxygenation reactions catalyzed by the rieske nonheme iron oxygenase carbazole 1,9a-dioxygenase. Appl Environ Microbiol 2014; 80:2821-32. [PMID: 24584240 DOI: 10.1128/aem.04000-13] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Carbazole 1,9a-dioxygenase (CARDO), a Rieske nonheme iron oxygenase (RO), is a three-component system composed of a terminal oxygenase (Oxy), ferredoxin, and a ferredoxin reductase. Oxy has angular dioxygenation activity against carbazole. Previously, site-directed mutagenesis of the Oxy-encoding gene from Janthinobacterium sp. strain J3 generated the I262V, F275W, Q282N, and Q282Y Oxy derivatives, which showed oxygenation capabilities different from those of the wild-type enzyme. To understand the structural features resulting in the different oxidation reactions, we determined the crystal structures of the derivatives, both free and complexed with substrates. The I262V, F275W, and Q282Y derivatives catalyze the lateral dioxygenation of carbazole with higher yields than the wild type. A previous study determined the crystal structure of Oxy complexed with carbazole and revealed that the carbonyl oxygen of Gly178 hydrogen bonds with the imino nitrogen of carbazole. In these derivatives, the carbazole was rotated approximately 15, 25, and 25°, respectively, compared to the wild type, creating space for a water molecule, which hydrogen bonds with the carbonyl oxygen of Gly178 and the imino nitrogen of carbazole. In the crystal structure of the F275W derivative complexed with fluorene, C-9 of fluorene, which corresponds to the imino nitrogen of carbazole, was oriented close to the mutated residue Trp275, which is on the opposite side of the binding pocket from the carbonyl oxygen of Gly178. Our structural analyses demonstrate that the fine-tuning of hydrophobic residues on the surface of the substrate-binding pocket in ROs causes a slight shift in the substrate-binding position that, in turn, favors specific oxygenation reactions toward various substrates.
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Matsuzawa J, Umeda T, Aikawa H, Suzuki C, Fujimoto Z, Okada K, Yamane H, Nojiri H. Crystallization and preliminary X-ray diffraction studies of the reduced form of the terminal oxygenase component of the Rieske nonhaem iron oxygenase system carbazole 1,9a-dioxygenase. Acta Crystallogr Sect F Struct Biol Cryst Commun 2013; 69:1284-7. [PMID: 24192370 PMCID: PMC3818054 DOI: 10.1107/s1744309113026754] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2013] [Accepted: 09/28/2013] [Indexed: 11/10/2022]
Abstract
The initial reaction of bacterial carbazole degradation is catalysed by carbazole 1,9a-dioxygenase, which consists of terminal oxygenase, ferredoxin and ferredoxin reductase components. The reduced form of the terminal oxygenase component was crystallized at 293 K by the hanging-drop vapour-diffusion method using PEG MME 550 as the precipitant under anaerobic conditions. The crystals diffracted to a resolution of 1.74 Å and belonged to space group P6(5), with unit-cell parameters a = b = 92.0, c = 243.6 Å. The asymmetric unit contained a trimer of terminal oxygenase molecules.
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Affiliation(s)
- Jun Matsuzawa
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Takashi Umeda
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Hiroki Aikawa
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Chiho Suzuki
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Zui Fujimoto
- Biomolecular Research Unit, National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602, Japan
| | - Kazunori Okada
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Hisakazu Yamane
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
- Department of Biosciences, Teikyo University, 1-1 Toyosatodai, Utsunomiya, Tochigi 320-0003, Japan
| | - Hideaki Nojiri
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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Daniele MA, Bandera YP, Sharma D, Rungta P, Roeder R, Sehorn MG, Foulger SH. Substrate-baited nanoparticles: a catch and release strategy for enzyme recognition and harvesting. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2012; 8:2083-90. [PMID: 22532510 PMCID: PMC3516911 DOI: 10.1002/smll.201200013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Revised: 02/14/2012] [Indexed: 05/31/2023]
Abstract
The isolation of a single type of protein from a complex mixture is vital for the characterization of the function, structure, and interactions of the protein of interest and is typically the most laborious aspect of the protein purification process. In this work, a model system is utilized to show the efficacy of synthesizing a "baited" nanoparticle to capture and recycle enzymes (proteins that catalyze chemical reactions) from crude cell lysate. Enzyme trapping and recycling is illustrated with the carbazole 1,9a-dioxygenase (CARDO) system, an enzyme important in bioremediation and natural product synthesis. The enzymes are baited with azide-modified carbazolyl moieties attached to poly(propargyl acrylate) nanoparticles through a click transformation. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis indicates the single-step procedure to immobilize the enzymes on the particles is capable of significantly concentrating the protein from raw lysate and sequestering all required components of the protein to maintain bioactivity. These results establish a universal model applicable to concentrating and extracting known substrate-protein pairs, but it can be an invaluable tool in recognizing unknown protein-ligand affinities.
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Affiliation(s)
- Michael A Daniele
- Center for Optical Materials Science and Engineering Technologies, School of Materials Science and Engineering, Department of Bioengineering, Clemson University, Clemson, SC 29634, USA
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Ashikawa Y, Fujimoto Z, Usami Y, Inoue K, Noguchi H, Yamane H, Nojiri H. Structural insight into the substrate- and dioxygen-binding manner in the catalytic cycle of rieske nonheme iron oxygenase system, carbazole 1,9a-dioxygenase. BMC STRUCTURAL BIOLOGY 2012; 12:15. [PMID: 22727022 PMCID: PMC3423008 DOI: 10.1186/1472-6807-12-15] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Accepted: 06/24/2012] [Indexed: 01/11/2023]
Abstract
BACKGROUND Dihydroxylation of tandemly linked aromatic carbons in a cis-configuration, catalyzed by multicomponent oxygenase systems known as Rieske nonheme iron oxygenase systems (ROs), often constitute the initial step of aerobic degradation pathways for various aromatic compounds. Because such RO reactions inherently govern whether downstream degradation processes occur, novel oxygenation mechanisms involving oxygenase components of ROs (RO-Os) is of great interest. Despite substantial progress in structural and physicochemical analyses, no consensus exists on the chemical steps in the catalytic cycles of ROs. Thus, determining whether conformational changes at the active site of RO-O occur by substrate and/or oxygen binding is important. Carbazole 1,9a-dioxygenase (CARDO), a RO member consists of catalytic terminal oxygenase (CARDO-O), ferredoxin (CARDO-F), and ferredoxin reductase. We have succeeded in determining the crystal structures of oxidized CARDO-O, oxidized CARDO-F, and both oxidized and reduced forms of the CARDO-O: CARDO-F binary complex. RESULTS In the present study, we determined the crystal structures of the reduced carbazole (CAR)-bound, dioxygen-bound, and both CAR- and dioxygen-bound CARDO-O: CARDO-F binary complex structures at 1.95, 1.85, and 2.00 Å resolution. These structures revealed the conformational changes that occur in the catalytic cycle. Structural comparison between complex structures in each step of the catalytic mechanism provides several implications, such as the order of substrate and dioxygen bindings, the iron-dioxygen species likely being Fe(III)-(hydro)peroxo, and the creation of room for dioxygen binding and the promotion of dioxygen binding in desirable fashion by preceding substrate binding. CONCLUSIONS The RO catalytic mechanism is proposed as follows: When the Rieske cluster is reduced, substrate binding induces several conformational changes (e.g., movements of the nonheme iron and the ligand residue) that create room for oxygen binding. Dioxygen bound in a side-on fashion onto nonheme iron is activated by reduction to the peroxo state [Fe(III)-(hydro)peroxo]. This state may react directly with the bound substrate, or O-O bond cleavage may occur to generate Fe(V)-oxo-hydroxo species prior to the reaction. After producing a cis-dihydrodiol, the product is released by reducing the nonheme iron. This proposed scheme describes the catalytic cycle of ROs and provides important information for a better understanding of the mechanism.
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Affiliation(s)
- Yuji Ashikawa
- Biotechnology Research Center, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
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11
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Distal end of 105-125 loop--a putative reductase binding domain of phthalate dioxygenase. Arch Biochem Biophys 2009; 487:10-8. [PMID: 19464996 DOI: 10.1016/j.abb.2009.05.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2009] [Revised: 05/14/2009] [Accepted: 05/17/2009] [Indexed: 11/21/2022]
Abstract
The phthalate dioxygenase system consists of the dioxygenase, PDO, which contains a Rieske [2Fe-2S] center and a Fe(II)-mononuclear center, and the reductase, PDR. Involvement of the distal end of the 105-125 loop of PDO in its interaction with PDR was tested by substituting charged residues in the loop with alanines and by replacing the conserved tryptophan-94. Compared to wild-type PDO, all variants had lower catalytic activity and the Rieske centers were reduced more slowly by reduced PDR. The rates of oxidation of the Rieske centers by oxygen, which represent electron transfer between the Rieske and mononuclear centers, were essentially unaffected. These results suggest that positively charged residues of the distal end of the 105-125 loop are collectively involved in PDR binding with the PDO. Contrary to expectations, Trp94 variants were not directly involved in electron transfer between PDR and PDO. The tryptophan appears to have mainly a structural role, apparently preserving the hydrophilic environment of the Rieske center.
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12
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Umeda T, Katsuki J, Usami Y, Inoue K, Noguchi H, Fujimoto Z, Ashikawa Y, Yamane H, Nojiri H. Crystallization and preliminary X-ray diffraction studies of a novel ferredoxin involved in the dioxygenation of carbazole by Novosphingobium sp. KA1. Acta Crystallogr Sect F Struct Biol Cryst Commun 2008; 64:632-635. [PMID: 18607094 PMCID: PMC2443972 DOI: 10.1107/s1744309108016278] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2008] [Accepted: 05/29/2008] [Indexed: 05/26/2023]
Abstract
Novosphingobium sp. KA1 uses carbazole 1,9a-dioxygenase (CARDO) as the first dioxygenase in its carbazole-degradation pathway. The CARDO of KA1 contains a terminal oxygenase component and two electron-transfer components: ferredoxin and ferredoxin reductase. In contrast to the CARDO systems of other species, the ferredoxin component of KA1 is a putidaredoxin-type protein. This novel ferredoxin was crystallized at 293 K by the hanging-drop vapour-diffusion method using PEG MME 550 as the precipitant under anaerobic conditions. The crystals belong to space group C222(1) and diffraction data were collected to a resolution of 1.9 A (the diffraction limit was 1.6 A).
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Affiliation(s)
- Takashi Umeda
- Biotechnology Research Center, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Junichi Katsuki
- Biotechnology Research Center, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Yusuke Usami
- Biotechnology Research Center, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Kengo Inoue
- Biotechnology Research Center, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Haruko Noguchi
- Biotechnology Research Center, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Zui Fujimoto
- Protein Research Unit, National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602, Japan
| | - Yuji Ashikawa
- Molecular Signaling Research Team, Structural Physiology Research Group, RIKEN Harima Institute SPring-8 Center, 1-1-1 Kouto, Sayo, Hyogo 679-5148, Japan
| | - Hisakazu Yamane
- Biotechnology Research Center, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Hideaki Nojiri
- Biotechnology Research Center, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
- Professional Programme for Agricultural Bioinformatics, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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Inoue K, Ashikawa Y, Usami Y, Noguchi H, Fujimoto Z, Yamane H, Nojiri H. Crystallization and preliminary crystallographic analysis of the ferredoxin component of carbazole 1,9a-dioxygenase from Nocardioides aromaticivorans IC177. Acta Crystallogr Sect F Struct Biol Cryst Commun 2007; 63:855-7. [PMID: 17909288 PMCID: PMC2339720 DOI: 10.1107/s1744309107041437] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2007] [Accepted: 08/22/2007] [Indexed: 11/10/2022]
Abstract
Carbazole 1,9a-dioxygenase (CARDO) catalyzes the dihydroxylation of carbazole by angular position (C9a) carbon bonding to the imino nitrogen and its adjacent C1 carbon. CARDO consists of a terminal oxygenase component and two electron-transfer components: ferredoxin and ferredoxin reductase. The ferredoxin component of carbazole 1,9a-dioxygenase from Nocardioides aromaticivorans IC177 was crystallized at 293 K using the hanging-drop vapour-diffusion method with ammonium sulfate as the precipitant. The crystals, which were improved by macroseeding, diffract to 2.0 A resolution and belong to space group P4(1)2(1)2.
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Affiliation(s)
- Kengo Inoue
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Yuji Ashikawa
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Yusuke Usami
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Haruko Noguchi
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
- Professional Programme for Agricultural Bioinformatics, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Zui Fujimoto
- Protein Research Unit, National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602, Japan
| | - Hisakazu Yamane
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Hideaki Nojiri
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
- Professional Programme for Agricultural Bioinformatics, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
- Correspondence e-mail:
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Ashikawa Y, Uchimura H, Fujimoto Z, Inoue K, Noguchi H, Yamane H, Nojiri H. Crystallization and preliminary X-ray diffraction studies of the ferredoxin reductase component in the Rieske nonhaem iron oxygenase system carbazole 1,9a-dioxygenase. Acta Crystallogr Sect F Struct Biol Cryst Commun 2007; 63:499-502. [PMID: 17554172 PMCID: PMC2335075 DOI: 10.1107/s174430910702163x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2007] [Accepted: 05/02/2007] [Indexed: 11/10/2022]
Abstract
Carbazole 1,9a-dioxygenase (CARDO), which consists of an oxygenase component (CARDO-O) and the electron-transport components ferredoxin (CARDO-F) and ferredoxin reductase (CARDO-R), catalyzes dihydroxylation at the C1 and C9a positions of carbazole. CARDO-R was crystallized at 277 K using the hanging-drop vapour-diffusion method with the precipitant PEG 8000. Two crystal types (types I and II) were obtained. The type I crystal diffracted to a maximum resolution of 2.80 A and belonged to space group P4(2)2(1)2, with unit-cell parameters a = b = 158.7, c = 81.4 A. The type II crystal was obtained in drops from which type I crystals had been removed; it diffracted to 2.60 A resolution and belonged to the same space group, with unit-cell parameters a = b = 161.8, c = 79.5 A.
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Affiliation(s)
- Yuji Ashikawa
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Hiromasa Uchimura
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Zui Fujimoto
- Protein Research Unit, National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602, Japan
| | - Kengo Inoue
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Haruko Noguchi
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
- Professional Programme for Agricultural Bioinformatics, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Hisakazu Yamane
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Hideaki Nojiri
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
- Professional Programme for Agricultural Bioinformatics, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
- Correspondence e-mail:
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Ashikawa Y, Fujimoto Z, Noguchi H, Habe H, Omori T, Yamane H, Nojiri H. Electron Transfer Complex Formation between Oxygenase and Ferredoxin Components in Rieske Nonheme Iron Oxygenase System. Structure 2006; 14:1779-89. [PMID: 17161368 DOI: 10.1016/j.str.2006.10.004] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2006] [Revised: 10/06/2006] [Accepted: 10/10/2006] [Indexed: 11/22/2022]
Abstract
Carbazole 1,9a-dioxygenase (CARDO), a member of the Rieske nonheme iron oxygenase system (ROS), consists of a terminal oxygenase (CARDO-O) and electron transfer components (ferredoxin [CARDO-F] and ferredoxin reductase [CARDO-R]). We determined the crystal structures of the nonreduced, reduced, and substrate-bound binary complexes of CARDO-O with its electron donor, CARDO-F, at 1.9, 1.8, and 2.0 A resolutions, respectively. These structures provide the first structure-based interpretation of intercomponent electron transfer between two Rieske [2Fe-2S] clusters of ferredoxin and oxygenase in ROS. Three molecules of CARDO-F bind to the subunit boundary of one CARDO-O trimeric molecule, and specific binding created by electrostatic and hydrophobic interactions with conformational changes suitably aligns the two Rieske clusters for electron transfer. Additionally, conformational changes upon binding carbazole resulted in the closure of a lid over the substrate-binding pocket, thereby seemingly trapping carbazole at the substrate-binding site.
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Affiliation(s)
- Yuji Ashikawa
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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Inoue K, Ashikawa Y, Usami Y, Noguchi H, Fujimoto Z, Yamane H, Nojiri H. Crystallization and preliminary X-ray diffraction studies of the terminal oxygenase component of carbazole 1,9a-dioxygenase from Nocardioides aromaticivorans IC177. Acta Crystallogr Sect F Struct Biol Cryst Commun 2006; 62:1212-4. [PMID: 17142899 PMCID: PMC2225353 DOI: 10.1107/s1744309106044939] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2006] [Accepted: 10/27/2006] [Indexed: 11/10/2022]
Abstract
Carbazole 1,9a-dioxygenase (CARDO) catalyzes the dihydroxylation of carbazole by angular-position (C9a) carbon bonding to the imino nitrogen and its adjacent C1 carbon. CARDO consists of a terminal oxygenase component and two electron-transfer components: ferredoxin and ferredoxin reductase. The terminal oxygenase component (43.9 kDa) of carbazole 1,9a-dioxygenase from Nocardioides aromaticivorans IC177 was crystallized at 293 K using the hanging-drop vapour-diffusion method with PEG 8000 as the precipitant. The crystals diffract to 2.3 A resolution and belong to space group C2.
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Affiliation(s)
- Kengo Inoue
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Yuji Ashikawa
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Yusuke Usami
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Haruko Noguchi
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
- Professional Programme for Agricultural Bioinformatics, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Zui Fujimoto
- Department of Biochemistry, National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602, Japan
| | - Hisakazu Yamane
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Hideaki Nojiri
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
- Professional Programme for Agricultural Bioinformatics, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
- Correspondence e-mail:
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