1
|
Quaye JA, Moni BM, Kugblenu JE, Gadda G. Oxidation of α-hydroxy acids by D-2-hydroxyglutarate dehydrogenase enzymes. Arch Biochem Biophys 2025; 768:110355. [PMID: 39993590 DOI: 10.1016/j.abb.2025.110355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2024] [Revised: 02/15/2025] [Accepted: 02/21/2025] [Indexed: 02/26/2025]
Abstract
α-Hydroxy acids are naturally occurring organic molecules with various medical and industrial applications. However, some α-hydroxy acids, like D-2-hydroxyglutarate (D2HG), have been implicated in cancers and neurometabolic disorders such as D2HG aciduria. Several studies on the D2HG oxidizing enzyme D-2-hydroxyglutarate dehydrogenase (D2HGDH) from various eukaryotic and prokaryotic sources focus on the use and application of the enzyme as biosensors for detecting D2HG. A recent gene knockout study on the bacterial D2HGDH homologs from Pseudomonas stutzeri and Pseudomonas aeruginosa identified the D2HGDH to be essential for bacterial survival by driving l-serine biosynthesis. Thus, D2HGDH is a good candidate for a therapeutic target against the multidrug-resistant P. aeruginosa. However, there is no consensus on the D2HGDH catalytic mechanism, and several D2HGDH homologs have not been characterized in their structural properties, which are two crucial features for therapeutic design. P. aeruginosa D2HGDH, the most extensively studied D2HGDH homolog, is emerging as a paradigm for D2HGDH and flavoproteins with metal ions in their active site. In this review, we have explored the structures of all published D2HGDH homologs from 12 species using AlphaFold 3 and highlighted the fully conserved structure and active site topologies of all D2HGDH homologs. Additionally, evolutionary and functional studies coupled with analyses of enzymatic activities reveal that prokaryotic and eukaryotic D2HGDH homologs, diverging from two distinct ancestors, may have differentially evolved to specialize in their α-hydroxy acid catalysis. Additionally, this review identifies all D2HGDH homologs as metal and FAD-dependent enzymes that employ a metal-triggered FAD reduction in their catalysis. Elucidation of the D2HGDH mechanism will allow designing antibiotics that target these enzymes as potential therapeutics against pathogenic bacteria like P. aeruginosa in addition to the application of D2HGDH homologs as biosensors.
Collapse
Affiliation(s)
- Joanna Afokai Quaye
- Departments of Chemistry, Georgia State University, Atlanta, GA, 30302-3965, USA
| | - Bilkis Mehrin Moni
- Departments of Chemistry, Georgia State University, Atlanta, GA, 30302-3965, USA; The Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA, 30302-3965, USA
| | | | - Giovanni Gadda
- Departments of Chemistry, Georgia State University, Atlanta, GA, 30302-3965, USA; Departments of Biology, Georgia State University, Atlanta, GA, 30302-3965, USA; The Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA, 30302-3965, USA.
| |
Collapse
|
2
|
Quaye J, Gadda G. Metal-Triggered FAD Reduction in d-2-Hydroxyglutarate Dehydrogenase from Pseudomonas aeruginosa PAO1. ACS BIO & MED CHEM AU 2025; 5:204-214. [PMID: 39990952 PMCID: PMC11843331 DOI: 10.1021/acsbiomedchemau.4c00108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2024] [Revised: 11/21/2024] [Accepted: 11/25/2024] [Indexed: 02/25/2025]
Abstract
Alcohol oxidation is an indispensable chemical reaction in biological systems. This process, biologically catalyzed by alcohol dehydrogenases (ADHs) and alcohol oxidases (AOXs), follows two distinct chemical routes depending on the cofactor. ADHs have been widely demonstrated to require Zn2+- and NAD(P)+-based cosubstrates. Except for galactose oxidase, AOXs achieve their conversion of alcohols to aldehydes or ketones using flavin-based cofactors. The FMN-dependent α-hydroxy acid-oxidizing enzymes and the glucose-methanol-choline (GMC) superfamily abstract their substrate's α-OH proton using a catalytic histidine, leading to substrate oxidation and flavin reduction. However, there is no known alcohol oxidation mechanism for enzymes requiring both a flavin and a metal. The Pseudomonas aeruginosad-2-hydroxyglutarate dehydrogenase (PaD2HGDH) is a recently characterized α-hydroxy acid dehydrogenase that converts d-2-hydroxyglutarate or d-malate to 2-ketoglutarate or oxaloacetate, respectively. PaD2HGDH requires FAD and Zn2+ for catalysis. Previous studies on PaD2HGDH have identified a highly conserved active site histidine residue whose position is topologically conserved for catalytic bases in FMN-dependent α-hydroxy acid-oxidizing enzymes and the GMC superfamily of oxidoreductases. In this study, solvent isotope effects (SIEs) coupled with pL-rate profiles and a viscosity control have been used to probe the role of the Zn2+ cofactor in the C2-OH oxidation of d-malate and flavin reduction of PaD2HGDH. The data revealed an inverse solvent equilibrium isotope effect (SEIE) of 0.51 ± 0.09 consistent with a Zn2+-triggered abstraction of the substrate C2-OH proton that initiates d-malate oxidation and flavin reduction. The system provides insights into the role of Zn2+ in the oxidation mechanism of PaD2HGDH and, by extension, metallo flavoprotein dehydrogenases.
Collapse
Affiliation(s)
- Joanna
Afokai Quaye
- Departments
of Chemistry, Georgia State University, Atlanta, Georgia 30302-3965, United States of
America
| | - Giovanni Gadda
- Departments
of Chemistry, Georgia State University, Atlanta, Georgia 30302-3965, United States of
America
- Biology, Georgia State University, Atlanta, Georgia 30302-3965, United States of
America
- The
Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia 30302-3965, United States of America
| |
Collapse
|
3
|
Wu J, Wang P, Wang W, Hu H, Wei Q, Bao C, Yan Y. Comprehensive Genomic and Proteomic Analysis Identifies Effectors of Fusarium oxysporum f. sp. melongenae. J Fungi (Basel) 2024; 10:828. [PMID: 39728324 DOI: 10.3390/jof10120828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2024] [Revised: 11/08/2024] [Accepted: 11/10/2024] [Indexed: 12/28/2024] Open
Abstract
Fusarium wilt in eggplant caused by F. oxysporum f. sp. melongenae is a major devastating soil-borne disease on a worldwide scale. Effectors play important roles in the interactions in pathogen-plant interactions. Identifying effectors is essential for elucidating the pathogenic mechanisms of phytopathogenic fungi. In this study, bioinformatic prediction approaches, including SignalP v5.0, TMHMM v2.0, WoLF PSORT, PredGPI, and EffectorP, were employed to screen for candidate secreted effector proteins (CSEPs) in F. oxysporum f. sp. melongenae. A total of 1019 proteins exhibiting characteristics typical of classical secretory proteins were identified, 301 of which demonstrated carbohydrate activity, and 194 CSEPs were identified. Furthermore, a total of 563 proteins from F. oxysporum f. sp. melongenae under induced conditions were identified using mass spectrometry-based label-free quantitative proteomics. These findings suggest a potential role of these CSEPs in the interaction between F. oxysporum f. sp. melongenae and eggplant, thereby contributing to a deeper understanding of the pathogenic mechanisms of F. oxysporum f. sp. melongenae and strategies for disease management.
Collapse
Affiliation(s)
- Jiayelu Wu
- Institute of Vegetable, Zhejiang Academy of Agricultural Science, Hangzhou 310021, China
| | - Pengfei Wang
- Zhejiang Normal University, Jinhua 321004, China
| | - Wuhong Wang
- Institute of Vegetable, Zhejiang Academy of Agricultural Science, Hangzhou 310021, China
| | - Haijiao Hu
- Institute of Vegetable, Zhejiang Academy of Agricultural Science, Hangzhou 310021, China
| | - Qingzhen Wei
- Institute of Vegetable, Zhejiang Academy of Agricultural Science, Hangzhou 310021, China
| | - Chonglai Bao
- Institute of Vegetable, Zhejiang Academy of Agricultural Science, Hangzhou 310021, China
| | - Yaqin Yan
- Institute of Vegetable, Zhejiang Academy of Agricultural Science, Hangzhou 310021, China
| |
Collapse
|
4
|
Comparative Analysis of Carbohydrate Active Enzymes in the Flammulina velutipes var. lupinicola Genome. Microorganisms 2020; 9:microorganisms9010020. [PMID: 33374587 PMCID: PMC7822412 DOI: 10.3390/microorganisms9010020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/17/2020] [Accepted: 12/18/2020] [Indexed: 11/17/2022] Open
Abstract
The purpose of this study was to determine the genome sequence of Flammulina velutipes var. lupinicola based on next-generation sequencing (NGS) and to identify the genes encoding carbohydrate-active enzymes (CAZymes) in the genome. The optimal assembly (71 kmer) based on ABySS de novo assembly revealed a total length of 33,223,357 bp (49.53% GC content). A total of 15,337 gene structures were identified in the F. velutipes var. lupinicola genome using ab initio gene prediction method with Funannotate pipeline. Analysis of the orthologs revealed that 11,966 (96.6%) out of the 15,337 predicted genes belonged to the orthogroups and 170 genes were specific for F. velutipes var. lupinicola. CAZymes are divided into six classes: auxiliary activities (AAs), glycosyltransferases (GTs), carbohydrate esterases (CEs), polysaccharide lyases (PLs), glycoside hydrolases (GHs), and carbohydrate-binding modules (CBMs). A total of 551 genes encoding CAZymes were identified in the F. velutipes var. lupinicola genome by analyzing the dbCAN meta server database (HMMER, Hotpep, and DIAMOND searches), which consisted of 54-95 AAs, 145-188 GHs, 55-73 GTs, 6-19 PLs, 13-59 CEs, and 7-67 CBMs. CAZymes can be widely used to produce bio-based products (food, paper, textiles, animal feed, and biofuels). Therefore, information about the CAZyme repertoire of the F. velutipes var. lupinicola genome will help in understanding the lignocellulosic machinery and in-depth studies will provide opportunities for using this fungus for biotechnological and industrial applications.
Collapse
|
5
|
Quaye JA, Gadda G. Kinetic and Bioinformatic Characterization of d-2-Hydroxyglutarate Dehydrogenase from Pseudomonas aeruginosa PAO1. Biochemistry 2020; 59:4833-4844. [PMID: 33301690 DOI: 10.1021/acs.biochem.0c00832] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
d-2-Hydroxyglutarate dehydrogenase from Pseudomonas aeruginosa PAO1 (PaD2HGDH) catalyzes the oxidation of d-2-hydroxyglutarate to 2-ketoglutarate, which is a necessary step in the serine biosynthetic pathway. The dependence of P. aeruginosa on PaD2HGDH makes the enzyme a potential therapeutic target against P. aeruginosa. In this study, recombinant His-tagged PaD2HGDH was expressed and purified to high levels from gene PA0317, which was previously annotated as an FAD-binding PCMH-type domain-containing protein. The enzyme cofactor was identified as FAD with fluorescence emission after phosphodiesterase treatment and with mass spectrometry analysis. PaD2HGDH had a kcat value of 11 s-1 and a Km value of 60 μM with d-2-hydroxyglutarate at pH 7.4 and 25 °C. The enzyme was also active with d-malate but did not react with molecular oxygen. Steady-state kinetics with d-malate and phenazine methosulfate as an electron acceptor established a mechanism that was consistent with ping-pong bi-bi steady-state kinetics at pH 7.4. A comparison of the kcat/Km values with d-2-hydroxyglutarate and d-malate suggested that the C5 carboxylate of d-2-hydroxyglutarate is important for the substrate specificity of the enzyme. Other homologues of the enzyme have been previously grouped in the VAO/PMCH family of flavoproteins. PaD2HGDH shares fully conserved residues with other α-hydroxy acid oxidizing enzymes, and these conserved residues are found in the active site of the PaD2HDGH homology model. An Enzyme Function Initiative-Enzyme Similarity Tool Sequence Similarity Network analysis suggests a functional difference between PaD2HGDH and human D2HGDH, and no relationship with VAO. A phylogenetic tree analysis of PaD2HGDH, VAO, and human D2HGDH establishes genetic diversity among these enzymes.
Collapse
|
6
|
High-level expression of aryl-alcohol oxidase 2 from Pleurotus eryngii in Pichia pastoris for production of fragrances and bioactive precursors. Appl Microbiol Biotechnol 2020; 104:9205-9218. [PMID: 32949280 PMCID: PMC7567689 DOI: 10.1007/s00253-020-10878-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 08/14/2020] [Accepted: 09/02/2020] [Indexed: 12/13/2022]
Abstract
Abstract The fungal secretome comprises various oxidative enzymes participating in the degradation of lignocellulosic biomass as a central step in carbon recycling. Among the secreted enzymes, aryl-alcohol oxidases (AAOs) are of interest for biotechnological applications including production of bio-based precursors for plastics, bioactive compounds, and flavors and fragrances. Aryl-alcohol oxidase 2 (PeAAO2) from the fungus Pleurotus eryngii was heterologously expressed and secreted at one of the highest yields reported so far of 315 mg/l using the methylotrophic yeast Pichia pastoris (recently reclassified as Komagataella phaffii). The glycosylated PeAAO2 exhibited a high stability in a broad pH range between pH 3.0 and 9.0 and high thermal stability up to 55 °C. Substrate screening with 41 compounds revealed that PeAAO2 oxidized typical AAO substrates like p-anisyl alcohol, veratryl alcohol, and trans,trans-2,4-hexadienol with up to 8-fold higher activity than benzyl alcohol. Several compounds not yet reported as substrates for AAOs were oxidized by PeAAO2 as well. Among them, cumic alcohol and piperonyl alcohol were oxidized to cuminaldehyde and piperonal with high catalytic efficiencies of 84.1 and 600.2 mM−1 s−1, respectively. While the fragrance and flavor compound piperonal also serves as starting material for agrochemical and pharmaceutical building blocks, various positive health effects have been attributed to cuminaldehyde including anticancer, antidiabetic, and neuroprotective effects. PeAAO2 is thus a promising biocatalyst for biotechnological applications. Key points • Aryl-alcohol oxidase PeAAO2 from P. eryngii was produced in P. pastoris at 315 mg/l. • Purified enzyme exhibited stability over a broad pH and temperature range. • Oxidation products cuminaldehyde and piperonal are of biotechnological interest. Graphical abstract![]() Electronic supplementary material The online version of this article (10.1007/s00253-020-10878-4) contains supplementary material, which is available to authorized users.
Collapse
|
7
|
Abstract
Aryl-alcohol oxidases (AAO) constitute a family of FAD-containing enzymes, included in the glucose-methanol-choline oxidase/dehydrogenase superfamily of proteins. They are commonly found in fungi, where their eco-physiological role is to produce hydrogen peroxide that activates ligninolytic peroxidases in white-rot (lignin-degrading) basidiomycetes or to trigger the Fenton reactions in brown-rot (carbohydrate-degrading) basidiomycetes. These enzymes catalyze the oxidation of a plethora of aromatic, and some aliphatic, polyunsaturated alcohols bearing conjugated primary hydroxyl group. Besides, the enzymes show activity on the hydrated forms of the corresponding aldehydes. Some AAO features, such as the broad range of substrates that it can oxidize (with the only need of molecular oxygen as co-substrate) and its stereoselective mechanism, confer good properties to these enzymes as industrial biocatalysts. In fact, AAO can be used for different biotechnological applications, such as flavor synthesis, secondary alcohol deracemization and oxidation of furfurals for the production of furandicarboxylic acid as a chemical building block. Also, AAO can participate in processes of interest in the wood biorefinery and textile industries as an auxiliary enzyme providing hydrogen peroxide to ligninolytic or dye-decolorizing peroxidases. Both rational design and directed molecular evolution have been employed to engineer AAO for some of the above biotechnological applications.
Collapse
Affiliation(s)
- Ana Serrano
- Centro de Investigaciones Biológicas Margarita Salas (CIB), CSIC, Madrid, Spain.
| | - Juan Carro
- Centro de Investigaciones Biológicas Margarita Salas (CIB), CSIC, Madrid, Spain
| | - Angel T Martínez
- Centro de Investigaciones Biológicas Margarita Salas (CIB), CSIC, Madrid, Spain.
| |
Collapse
|
8
|
Peterbauer CK. Pyranose dehydrogenases: Rare enzymes for electrochemistry and biocatalysis. Bioelectrochemistry 2020; 132:107399. [DOI: 10.1016/j.bioelechem.2019.107399] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 09/26/2019] [Accepted: 09/26/2019] [Indexed: 10/25/2022]
|
9
|
Park YJ, Lee CS, Kong WS. Genomic Insights into the Fungal Lignocellulolytic Machinery of Flammulina rossica. Microorganisms 2019; 7:microorganisms7100421. [PMID: 31597238 PMCID: PMC6843371 DOI: 10.3390/microorganisms7100421] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 09/27/2019] [Accepted: 09/28/2019] [Indexed: 11/16/2022] Open
Abstract
Next-generation sequencing (NGS) of the Flammulina rossica (wood-rotting basidiomycete) genome was performed to identify its carbohydrate-active enzymes (CAZymes). De novo genome assembly (31 kmer) revealed a total length of 35,646,506 bp (49.79% GC content). In total, 12,588 gene models of F. rossica were predicted using an ab initio gene prediction tool (AUGUSTUS). Orthologous analysis with other fungal species revealed that 7433 groups contained at least one F. rossica gene. Additionally, 12,033 (95.6%) of 12,588 genes for F. rossica proteins had orthologs among the Dikarya, and F. rossica contained 12 species-specific genes. CAZyme annotation in the F. rossica genome revealed 511 genes predicted to encode CAZymes including 102 auxiliary activities, 236 glycoside hydrolases, 94 glycosyltransferases, 19 polysaccharide lyases, 56 carbohydrate esterases, and 21 carbohydrate binding-modules. Among the 511 genes, several genes were predicted to simultaneously encode two different CAZymes such as glycoside hydrolases (GH) as well as carbohydrate-binding module (CBM). The genome information of F. rossica offers opportunities to understand the wood-degrading machinery of this fungus and will be useful for biotechnological and industrial applications.
Collapse
Affiliation(s)
- Young-Jin Park
- Department of Biomedical Chemistry, Research Institute for Biomedical & Health Science, College of Biomedical and Health Science, Konkuk University, 268 Chungwon-daero, Chungju-si 27478, Korea.
| | - Chang-Soo Lee
- Department of Biomedical Chemistry, Research Institute for Biomedical & Health Science, College of Biomedical and Health Science, Konkuk University, 268 Chungwon-daero, Chungju-si 27478, Korea.
| | - Won-Sik Kong
- Mushroom Research Division, National Institute of Horticultural and Herbal Science, Rural Development Administration, 92, Bisan-ro, Eumseong-gun 27709, Korea.
| |
Collapse
|
10
|
Sützl L, Foley G, Gillam EMJ, Bodén M, Haltrich D. The GMC superfamily of oxidoreductases revisited: analysis and evolution of fungal GMC oxidoreductases. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:118. [PMID: 31168323 PMCID: PMC6509819 DOI: 10.1186/s13068-019-1457-0] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 05/02/2019] [Indexed: 05/03/2023]
Abstract
BACKGROUND The glucose-methanol-choline (GMC) superfamily is a large and functionally diverse family of oxidoreductases that share a common structural fold. Fungal members of this superfamily that are characterised and relevant for lignocellulose degradation include aryl-alcohol oxidoreductase, alcohol oxidase, cellobiose dehydrogenase, glucose oxidase, glucose dehydrogenase, pyranose dehydrogenase, and pyranose oxidase, which together form family AA3 of the auxiliary activities in the CAZy database of carbohydrate-active enzymes. Overall, little is known about the extant sequence space of these GMC oxidoreductases and their phylogenetic relations. Although some individual forms are well characterised, it is still unclear how they compare in respect of the complete enzyme class and, therefore, also how generalizable are their characteristics. RESULTS To improve the understanding of the GMC superfamily as a whole, we used sequence similarity networks to cluster large numbers of fungal GMC sequences and annotate them according to functionality. Subsequently, different members of the GMC superfamily were analysed in detail with regard to their sequences and phylogeny. This allowed us to define the currently characterised sequence space and show that complete clades of some enzymes have not been studied in any detail to date. Finally, we interpret our results from an evolutionary perspective, where we could show, for example, that pyranose dehydrogenase evolved from aryl-alcohol oxidoreductase after a change in substrate specificity and that the cytochrome domain of cellobiose dehydrogenase was regularly lost during evolution. CONCLUSIONS This study offers new insights into the sequence variation and phylogenetic relationships of fungal GMC/AA3 sequences. Certain clades of these GMC enzymes identified in our phylogenetic analyses are completely uncharacterised to date, and might include enzyme activities of varying specificities and/or activities that are hitherto unstudied.
Collapse
Affiliation(s)
- Leander Sützl
- Food Biotechnology Laboratory, Department of Food Science and Technology, BOKU-University of Natural Resources and Life Sciences Vienna, Vienna, Austria
- Doctoral Programme BioToP-Biomolecular Technology of Proteins, BOKU-University of Natural Resources and Life Sciences Vienna, Vienna, Austria
| | - Gabriel Foley
- School of Chemistry & Molecular Biosciences, The University of Queensland, Brisbane, Australia
| | - Elizabeth M J Gillam
- School of Chemistry & Molecular Biosciences, The University of Queensland, Brisbane, Australia
| | - Mikael Bodén
- School of Chemistry & Molecular Biosciences, The University of Queensland, Brisbane, Australia
| | - Dietmar Haltrich
- Food Biotechnology Laboratory, Department of Food Science and Technology, BOKU-University of Natural Resources and Life Sciences Vienna, Vienna, Austria
- Doctoral Programme BioToP-Biomolecular Technology of Proteins, BOKU-University of Natural Resources and Life Sciences Vienna, Vienna, Austria
| |
Collapse
|
11
|
Park YJ, Kong WS. Genome-Wide Comparison of Carbohydrate-Active Enzymes (CAZymes) Repertoire of Flammulina ononidis. MYCOBIOLOGY 2018; 46:349-360. [PMID: 30637143 PMCID: PMC6319455 DOI: 10.1080/12298093.2018.1537585] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 10/09/2018] [Accepted: 10/12/2018] [Indexed: 06/09/2023]
Abstract
Whole-genome sequencing of Flammulina ononidis, a wood-rotting basidiomycete, was performed to identify genes associated with carbohydrate-active enzymes (CAZymes). A total of 12,586 gene structures with an average length of 2009 bp were predicted by the AUGUSTUS tool from a total 35,524,258 bp length of de novo genome assembly (49.76% GC). Orthologous analysis with other fungal species revealed that 7051 groups contained at least one F. ononidis gene. In addition, 11,252 (89.5%) of 12,586 genes for F. ononidis proteins had orthologs among the Dikarya, and F. ononidis contained 8 species-specific genes, of which 5 genes were paralogous. CAZyme prediction revealed 524 CAZyme genes, including 228 for glycoside hydrolases, 21 for polysaccharide lyases, 87 for glycosyltransferases, 61 for carbohydrate esterases, 87 with auxiliary activities, and 40 for carbohydrate-binding modules in the F. ononidis genome. This genome information including CAZyme repertoire will be useful to understand lignocellulolytic machinery of this white rot fungus F. ononidis.
Collapse
Affiliation(s)
- Young-Jin Park
- Department of Integrated Biosciences, Research Institute for Biomedical & Health Science, College of Biomedical and Health Science, Konkuk University, Chungju-si, Korea
| | - Won-Sik Kong
- Mushroom Research Division, National Institute of Horticultural and Herbal Science, Rural Development Administration, Eumseong-gun, Korea
| |
Collapse
|
12
|
Genome Sequencing and Carbohydrate-Active Enzyme (CAZyme) Repertoire of the White Rot Fungus Flammulina elastica. Int J Mol Sci 2018; 19:ijms19082379. [PMID: 30104475 PMCID: PMC6121412 DOI: 10.3390/ijms19082379] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 07/30/2018] [Accepted: 08/07/2018] [Indexed: 11/25/2022] Open
Abstract
Next-generation sequencing (NGS) of the Flammulina elastica (wood-rotting basidiomycete) genome was performed to identify carbohydrate-active enzymes (CAZymes). The resulting assembly (31 kmer) revealed a total length of 35,045,521 bp (49.7% GC content). Using the AUGUSTUS tool, 12,536 total gene structures were predicted by ab initio gene prediction. An analysis of orthologs revealed that 6806 groups contained at least one F. elastica protein. Among the 12,536 predicted genes, F. elastica contained 24 species-specific genes, of which 17 genes were paralogous. CAZymes are divided into five classes: glycoside hydrolases (GHs), carbohydrate esterases (CEs), polysaccharide lyases (PLs), glycosyltransferases (GTs), and auxiliary activities (AA). In the present study, annotation of the predicted amino acid sequences from F. elastica genes using the dbCAN CAZyme database revealed 508 CAZymes, including 82 AAs, 218 GHs, 89 GTs, 18 PLs, 59 CEs, and 42 carbohydrate binding modules in the F. elastica genome. Although the CAZyme repertoire of F. elastica was similar to those of other fungal species, the total number of GTs in F. elastica was larger than those of other basidiomycetes. This genome information elucidates newly identified wood-degrading machinery in F. elastica, offers opportunities to better understand this fungus, and presents possibilities for more detailed studies on lignocellulosic biomass degradation that may lead to future biotechnological and industrial applications.
Collapse
|
13
|
Jackson CA, Couger MB, Prabhakaran M, Ramachandriya KD, Canaan P, Fathepure BZ. Isolation and characterization of Rhizobium sp. strain YS-1r that degrades lignin in plant biomass. J Appl Microbiol 2017; 122:940-952. [PMID: 28092137 DOI: 10.1111/jam.13401] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 01/05/2017] [Accepted: 01/09/2017] [Indexed: 11/28/2022]
Abstract
AIMS The aim of this work was to isolate novel lignin-degrading organisms. METHODS AND RESULTS Several pure cultures of bacteria that degrade lignin were isolated from bacterial consortia developed from decaying biomass. Among the isolates, Rhizobium sp. strain YS-1r (closest relative of Rhizobium petrolearium strain SL-1) was explored for its lignin-degrading ability. Microcosm studies showed that strain YS-1r was able to degrade a variety of lignin monomers, dimers and also native lignin in switchgrass and alfalfa. The isolate demonstrated lignin peroxidase (LiP) activity when grown on alkali lignin, p-anisoin, switchgrass or alfalfa, and only negligible activity was measured in glucose-grown cells suggesting inducible nature of the LiP activity. Analysis of the strain YS-1r genome revealed the presence of a variety of genes that code for various lignin-oxidizing, H2 O2 -producing as well as polysaccharide-hydrolysing enzymes. CONCLUSIONS This study shows both the genomic and physiological capability of bacteria in the genus Rhizobium to metabolize lignin and lignin-like compounds. This is the first detailed report on the lignocellulose-degrading ability of a Rhizobium species and thus this study expands the role of alpha-proteobacteria in the degradation of lignin. SIGNIFICANCE AND IMPACT OF THE STUDY The organism's ability to degrade lignin is significant since Rhizobia are widespread in soil, water and plant rhizospheres and some fix atmospheric nitrogen and also have the ability to degrade aromatic hydrocarbons.
Collapse
Affiliation(s)
- C A Jackson
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
| | - M B Couger
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
| | - M Prabhakaran
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
| | - K D Ramachandriya
- Department of Biosystems and Agricultural Engineering, Oklahoma State University, Stillwater, OK, USA
| | - P Canaan
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK, USA
| | - B Z Fathepure
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
| |
Collapse
|
14
|
Kameshwar AKS, Qin W. Lignin Degrading Fungal Enzymes. PRODUCTION OF BIOFUELS AND CHEMICALS FROM LIGNIN 2016. [DOI: 10.1007/978-981-10-1965-4_4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
|
15
|
Rahfeld P, Kirsch R, Kugel S, Wielsch N, Stock M, Groth M, Boland W, Burse A. Independently recruited oxidases from the glucose-methanol-choline oxidoreductase family enabled chemical defences in leaf beetle larvae (subtribe Chrysomelina) to evolve. Proc Biol Sci 2015; 281:20140842. [PMID: 24943369 DOI: 10.1098/rspb.2014.0842] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Larvae of the leaf beetle subtribe Chrysomelina sensu stricto repel their enemies by displaying glandular secretions that contain defensive compounds. These repellents can be produced either de novo (iridoids) or by using plant-derived precursors (e.g. salicylaldehyde). The autonomous production of iridoids, as in Phaedon cochleariae, is the ancestral chrysomeline chemical defence and predates the evolution of salicylaldehyde-based defence. Both biosynthesis strategies include an oxidative step of an alcohol intermediate. In salicylaldehyde-producing species, this step is catalysed by salicyl alcohol oxidases (SAOs) of the glucose-methanol-choline (GMC) oxidoreductase superfamily, but the enzyme oxidizing the iridoid precursor is unknown. Here, we show by in vitro as well as in vivo experiments that P. cochleariae also uses an oxidase from the GMC superfamily for defensive purposes. However, our phylogenetic analysis of chrysomeline GMC oxidoreductases revealed that the oxidase of the iridoid pathway originated from a GMC clade different from that of the SAOs. Thus, the evolution of a host-independent chemical defence followed by a shift to a host-dependent chemical defence in chrysomeline beetles coincided with the utilization of genes from different GMC subfamilies. These findings illustrate the importance of the GMC multi-gene family for adaptive processes in plant-insect interactions.
Collapse
Affiliation(s)
- Peter Rahfeld
- Department of Bioorganic Chemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Roy Kirsch
- Department of Entomology, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Susann Kugel
- Department of Bioorganic Chemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Natalie Wielsch
- Research Group Mass Spectrometry/Proteomics, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Magdalena Stock
- Department of Bioorganic Chemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Marco Groth
- Genome Analysis Group, Leibniz Institute for Age Research, Fritz Lipmann Institute, Jena, Germany
| | - Wilhelm Boland
- Department of Bioorganic Chemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Antje Burse
- Department of Bioorganic Chemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
| |
Collapse
|
16
|
Zelena K, Eisele N, Berger RG. Escherichia coli as a production host for novel enzymes from basidiomycota. Biotechnol Adv 2014; 32:1382-95. [DOI: 10.1016/j.biotechadv.2014.08.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 08/14/2014] [Accepted: 08/25/2014] [Indexed: 01/14/2023]
|
17
|
Yakovlev IA, Hietala AM, Courty PE, Lundell T, Solheim H, Fossdal CG. Genes associated with lignin degradation in the polyphagous white-rot pathogen Heterobasidion irregulare show substrate-specific regulation. Fungal Genet Biol 2013; 56:17-24. [PMID: 23665189 DOI: 10.1016/j.fgb.2013.04.011] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Revised: 04/26/2013] [Accepted: 04/29/2013] [Indexed: 11/15/2022]
Abstract
The pathogenic white-rot basidiomycete Heterobasidion irregulare is able to remove lignin and hemicellulose prior to cellulose during the colonization of root and stem xylem of conifer and broadleaf trees. We identified and followed the regulation of expression of genes belonging to families encoding ligninolytic enzymes. In comparison with typical white-rot fungi, the H. irregulare genome has exclusively the short-manganese peroxidase type encoding genes (6 short-MnPs) and thereby a slight contraction in the pool of class II heme-containing peroxidases, but an expansion of the MCO laccases with 17 gene models. Furthermore, the genome shows a versatile set of other oxidoreductase genes putatively involved in lignin oxidation and conversion, including 5 glyoxal oxidases, 19 quinone-oxidoreductases and 12 aryl-alcohol oxidases. Their genetic multiplicity and gene-specific regulation patterns on cultures based on defined lignin, cellulose or Norway spruce lignocellulose substrates suggest divergent specificities and physiological roles for these enzymes. While the short-MnP encoding genes showed similar transcript levels upon fungal growth on heartwood and reaction zone (RZ), a xylem defense tissue rich in phenolic compounds unique to trees, a subset of laccases showed higher gene expression in the RZ cultures. In contrast, other oxidoreductases depending on initial MnP activity showed generally lower transcript levels on RZ than on heartwood. These data suggest that the rate of fungal oxidative conversion of xylem lignin differs between spruce RZ and heartwood. It is conceivable that in RZ part of the oxidoreductase activities of laccases are related to the detoxification of phenolic compounds involved in host-defense. Expression of the several short-MnP enzymes indicated an important role for these enzymes in effective delignification of wood by H. irregulare.
Collapse
Affiliation(s)
- Igor A Yakovlev
- Norwegian Forest and Landscape Institute, PO Box 115, N-1431 Ås, Norway
| | | | | | | | | | | |
Collapse
|
18
|
An overview on alcohol oxidases and their potential applications. Appl Microbiol Biotechnol 2013; 97:4259-75. [DOI: 10.1007/s00253-013-4842-9] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Revised: 03/06/2013] [Accepted: 03/07/2013] [Indexed: 10/27/2022]
|
19
|
Hernández-Ortega A, Lucas F, Ferreira P, Medina M, Guallar V, Martínez AT. Role of Active Site Histidines in the Two Half-Reactions of the Aryl-Alcohol Oxidase Catalytic Cycle. Biochemistry 2012; 51:6595-608. [DOI: 10.1021/bi300505z] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Fátima Lucas
- Joint BSC-IRB
Research Program
in Computational Biology, Barcelona Supercomputing Center, Jordi Girona 29, E-08034 Barcelona, Spain
| | - Patricia Ferreira
- Department of Biochemistry and
Molecular and Cellular Biology and Institute of Biocomputation and
Physics of Complex Systems, University of Zaragoza, E-50009 Zaragoza, Spain
| | - Milagros Medina
- Department of Biochemistry and
Molecular and Cellular Biology and Institute of Biocomputation and
Physics of Complex Systems, University of Zaragoza, E-50009 Zaragoza, Spain
| | - Victor Guallar
- Joint BSC-IRB
Research Program
in Computational Biology, Barcelona Supercomputing Center, Jordi Girona 29, E-08034 Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys 23, E-08010 Barcelona, Spain
| | - Angel T. Martínez
- Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, E-28040
Madrid, Spain
| |
Collapse
|
20
|
Yang DD, François JM, de Billerbeck GM. Cloning, expression and characterization of an aryl-alcohol dehydrogenase from the white-rot fungus Phanerochaete chrysosporium strain BKM-F-1767. BMC Microbiol 2012; 12:126. [PMID: 22742413 PMCID: PMC3507735 DOI: 10.1186/1471-2180-12-126] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 04/16/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The white-rot fungus Phanerochaete chrysosporium is among the small group of fungi that can degrade lignin to carbon dioxide while leaving the crystalline cellulose untouched. The efficient lignin oxidation system of this fungus requires cyclic redox reactions involving the reduction of aryl-aldehydes to the corresponding alcohols by aryl-alcohol dehydrogenase. However, the biochemical properties of this enzyme have not been extensively studied. These are of most interest for the design of metabolic engineering/synthetic biology strategies in the field of biotechnological applications of this enzyme. RESULTS We report here the cloning of an aryl-alcohol dehydrogenase cDNA from the white-rot fungus Phanerochaete chrysosporium, its expression in Escherichia coli and the biochemical characterization of the encoded GST and His6 tagged protein. The purified recombinant enzyme showed optimal activity at 37°C and at pH 6.4 for the reduction of aryl- and linear aldehydes with NADPH as coenzyme. NADH could also be the electron donor, while having a higher Km (220 μM) compared to that of NADPH (39 μM). The purified recombinant enzyme was found to be active in the reduction of more than 20 different aryl- and linear aldehydes showing highest specificity for mono- and dimethoxylated Benzaldehyde at positions 3, 4, 3,4 and 3,5. The enzyme was also capable of oxidizing aryl-alcohols with NADP(+) at 30°C and an optimum pH of 10.3 but with 15 to 100-fold lower catalytic efficiency than for the reduction reaction. CONCLUSIONS In this work, we have characterized the biochemical properties of an aryl-alcohol dehydrogenase from the white-rot fungus Phanerochaete chrysosporium. We show that this enzyme functions in the reductive sense under physiological conditions and that it displays relatively large substrate specificity with highest activity towards the natural compound Veratraldehyde.
Collapse
Affiliation(s)
- Dong-Dong Yang
- Université de Toulouse; INSA, UPS, INP; LISBP, 135 Avenue de Rangueil, Toulouse, F-31077, France
| | | | | |
Collapse
|
21
|
Fungal aryl-alcohol oxidase: a peroxide-producing flavoenzyme involved in lignin degradation. Appl Microbiol Biotechnol 2012; 93:1395-410. [DOI: 10.1007/s00253-011-3836-8] [Citation(s) in RCA: 121] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Revised: 12/06/2011] [Accepted: 12/09/2011] [Indexed: 11/30/2022]
|
22
|
Hernández-Ortega A, Lucas F, Ferreira P, Medina M, Guallar V, Martínez AT. Modulating O2 reactivity in a fungal flavoenzyme: involvement of aryl-alcohol oxidase Phe-501 contiguous to catalytic histidine. J Biol Chem 2011; 286:41105-14. [PMID: 21940622 DOI: 10.1074/jbc.m111.282467] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Aryl-alcohol oxidase (AAO) is a flavoenzyme responsible for activation of O(2) to H(2)O(2) in fungal degradation of lignin. The AAO crystal structure shows a buried active site connected to the solvent by a hydrophobic funnel-shaped channel, with Phe-501 and two other aromatic residues forming a narrow bottleneck that prevents the direct access of alcohol substrates. However, ligand diffusion simulations show O(2) access to the active site following this channel. Site-directed mutagenesis of Phe-501 yielded a F501A variant with strongly reduced O(2) reactivity. However, a variant with increased reactivity, as shown by kinetic constants and steady-state oxidation degree, was obtained by substitution of Phe-501 with tryptophan. The high oxygen catalytic efficiency of F501W, ∼2-fold that of native AAO and ∼120-fold that of F501A, seems related to a higher O(2) availability because the turnover number was slightly decreased with respect to the native enzyme. Free diffusion simulations of O(2) inside the active-site cavity of AAO (and several in silico Phe-501 variants) yielded >60% O(2) population at 3-4 Å from flavin C4a in F501W compared with 44% in AAO and only 14% in F501A. Paradoxically, the O(2) reactivity of AAO decreased when the access channel was enlarged and increased when it was constricted by introducing a tryptophan residue. This is because the side chain of Phe-501, contiguous to the catalytic histidine (His-502 in AAO), helps to position O(2) at an adequate distance from flavin C4a (and His-502 Nε). Phe-501 substitution with a bulkier tryptophan residue resulted in an increase in the O(2) reactivity of this flavoenzyme.
Collapse
Affiliation(s)
- Aitor Hernández-Ortega
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu 9, E-28040 Madrid, Spain
| | | | | | | | | | | |
Collapse
|
23
|
Ames BD, Haynes SW, Gao X, Evans BS, Kelleher NL, Tang Y, Walsh CT. Complexity generation in fungal peptidyl alkaloid biosynthesis: oxidation of fumiquinazoline A to the heptacyclic hemiaminal fumiquinazoline C by the flavoenzyme Af12070 from Aspergillus fumigatus. Biochemistry 2011; 50:8756-69. [PMID: 21899262 DOI: 10.1021/bi201302w] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The human pathogen Aspergillus fumigatus makes a series of fumiquinazoline (FQ) peptidyl alkaloids of increasing scaffold complexity using L-Trp, 2 equiv of L-Ala, and the non-proteinogenic amino acid anthranilate as building blocks. The FQ gene cluster encodes two non-ribosomal peptide synthetases (NRPS) and two flavoproteins. The trimodular NRPS Af12080 assembles FQF (the first level of complexity) while the next two enzymes, Af12060 and Af12050, act in tandem in an oxidative annulation sequence to couple alanine to the indole side chain of FQF to yield the imidazolindolone-containing FQA. In this study we show that the fourth enzyme, the monocovalent flavoprotein Af12070, introduces a third layer of scaffold complexity by converting FQA to the spirohemiaminal FQC, presumably by catalyzing the formation of a transient imine within the pyrazinone ring (and therefore acting in an unprecedented manner as an FAD-dependent amide oxidase). FQC subsequently converts nonenzymatically to the known cyclic aminal FQD. We also investigated the effect of substrate structure on Af12070 activity and subsequent cyclization with a variety of FQA analogues, including an FQA diastereomer (2'-epi-FQA), which is an intermediate in the fungal biosynthesis of the tremorgenic tryptoquialanine. 2'-epi-FQA is processed by Af12070 to epi-FQD, not epi-FQC, illustrating that the delicate balance in product cyclization regiochemistry can be perturbed by a remote stereochemical center.
Collapse
Affiliation(s)
- Brian D Ames
- Department of Biological Chemistry & Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, United States
| | | | | | | | | | | | | |
Collapse
|
24
|
Substrate diffusion and oxidation in GMC oxidoreductases: an experimental and computational study on fungal aryl-alcohol oxidase. Biochem J 2011; 436:341-50. [DOI: 10.1042/bj20102090] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
AAO (aryl-alcohol oxidase) provides H2O2 in fungal degradation of lignin, a process of high biotechnological interest. The crystal structure of AAO does not show open access to the active site, where different aromatic alcohols are oxidized. In the present study we investigated substrate diffusion and oxidation in AAO compared with the structurally related CHO (choline oxidase). Cavity finder and ligand diffusion simulations indicate the substrate-entrance channel, requiring side-chain displacements and involving a stacking interaction with Tyr92. Mixed QM (quantum mechanics)/MM (molecular mechanics) studies combined with site-directed mutagenesis showed two active-site catalytic histidine residues, whose substitution strongly decreased both catalytic and transient-state reduction constants for p-anisyl alcohol in the H502A (over 1800-fold) and H546A (over 35-fold) variants. Combination of QM/MM energy profiles, protonation predictors, molecular dynamics, mutagenesis and pH profiles provide a robust answer regarding the nature of the catalytic base. The histidine residue in front of the FAD ring, AAO His502 (and CHO His466), acts as a base. For the two substrates assayed, it was shown that proton transfer preceded hydride transfer, although both processes are highly coupled. No stable intermediate was observed in the energy profiles, in contrast with that observed for CHO. QM/MM, together with solvent KIE (kinetic isotope effect) results, suggest a non-synchronous concerted mechanism for alcohol oxidation by AAO.
Collapse
|
25
|
Kinetic and chemical characterization of aldehyde oxidation by fungal aryl-alcohol oxidase. Biochem J 2010; 425:585-93. [PMID: 19891608 DOI: 10.1042/bj20091499] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Fungal AAO (aryl-alcohol oxidase) provides H2O2 for lignin biodegradation. AAO is active on benzyl alcohols that are oxidized to aldehydes. However, during oxidation of some alcohols, AAO forms more than a stoichiometric number of H2O2 molecules with respect to the amount of aldehyde detected due to a double reaction that involves aryl-aldehyde oxidase activity. The latter reaction was investigated using different benzylic aldehydes, whose oxidation to acids was demonstrated by GC-MS. The steady- and presteady state kinetic constants, together with the chromatographic results, revealed that the presence of substrate electron-withdrawing or electron-donating substituents had a strong influence on activity; the highest activity was with p-nitrobenzaldehyde and halogenated aldehydes and the lowest with methoxylated aldehydes. Moreover, activity was correlated to the aldehyde hydration rates estimated by 1H-NMR. These findings, together with the absence in the AAO active site of a residue able to drive oxidation via an aldehyde thiohemiacetal, suggested that oxidation mainly proceeds via the gem-diol species. The reaction mechanism (with a solvent isotope effect, 2H2Okred, of approx. 1.5) would be analogous to that described for alcohols, the reductive half-reaction involving concerted hydride transfer from the alpha-carbon and proton abstraction from one of the gem-diol hydroxy groups by a base. The existence of two steps of opposite polar requirements (hydration and hydride transfer) explains some aspects of aldehyde oxidation by AAO. Site-directed mutagenesis identified two histidine residues strongly involved in gem-diol oxidation and, unexpectedly, suggested that an active-site tyrosine residue could facilitate the oxidation of some aldehydes that show no detectable hydration. Double alcohol and aldehyde oxidase activities of AAO would contribute to H2O2 supply by the enzyme.
Collapse
|
26
|
Ferreira P, Hernandez-Ortega A, Herguedas B, Martínez AT, Medina M. Aryl-alcohol oxidase involved in lignin degradation: a mechanistic study based on steady and pre-steady state kinetics and primary and solvent isotope effects with two alcohol substrates. J Biol Chem 2009; 284:24840-7. [PMID: 19574215 DOI: 10.1074/jbc.m109.011593] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Aryl-alcohol oxidase (AAO) is a FAD-containing enzyme in the GMC (glucose-methanol-choline oxidase) family of oxidoreductases. AAO participates in fungal degradation of lignin, a process of high ecological and biotechnological relevance, by providing the hydrogen peroxide required by ligninolytic peroxidases. In the Pleurotus species, this peroxide is generated in the redox cycling of p-anisaldehyde, an extracellular fungal metabolite. In addition to p-anisyl alcohol, the enzyme also oxidizes other polyunsaturated primary alcohols. Its reaction mechanism was investigated here using p-anisyl alcohol and 2,4-hexadien-1-ol as two AAO model substrates. Steady state kinetic parameters and enzyme-monitored turnover were consistent with a sequential mechanism in which O(2) reacts with reduced AAO before release of the aldehyde product. Pre-steady state analysis revealed that the AAO reductive half-reaction is essentially irreversible and rate limiting during catalysis. Substrate and solvent kinetic isotope effects under steady and pre-steady state conditions (the latter showing approximately 9-fold slower enzyme reduction when alpha-bideuterated substrates were used, and approximately 13-fold slower reduction when both substrate and solvent effects were simultaneously evaluated) revealed a synchronous mechanism in which hydride transfer from substrate alpha-carbon to FAD and proton abstraction from hydroxyl occur simultaneously. This significantly differs from the general mechanism proposed for other members of the GMC oxidoreductase family that implies hydride transfer from a previously stabilized substrate alkoxide.
Collapse
Affiliation(s)
- Patricia Ferreira
- Centro de Investigaciones Biológicas (CIB), Consejo Superior de Investigaciones Científicas (CSIC), E28040 Madrid, Spain
| | | | | | | | | |
Collapse
|
27
|
Transcriptome and secretome analyses of Phanerochaete chrysosporium reveal complex patterns of gene expression. Appl Environ Microbiol 2009; 75:4058-68. [PMID: 19376920 DOI: 10.1128/aem.00314-09] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The wood decay basidiomycete Phanerochaete chrysosporium was grown under standard ligninolytic or cellulolytic conditions and subjected to whole-genome expression microarray analysis and liquid chromatography-tandem mass spectrometry of extracellular proteins. A total of 545 genes were flagged on the basis of significant changes in transcript accumulation and/or peptide sequences of the secreted proteins. Under nitrogen or carbon limitation, lignin and manganese peroxidase expression increased relative to nutrient replete medium. Various extracellular oxidases were also secreted in these media, supporting a physiological connection based on peroxide generation. Numerous genes presumed to be involved in mobilizing and recycling nitrogen were expressed under nitrogen limitation, and among these were several secreted glutamic acid proteases not previously observed. In medium containing microcrystalline cellulose as the sole carbon source, numerous genes encoding carbohydrate-active enzymes were upregulated. Among these were six members of the glycoside hydrolase family 61, as well as several polysaccharide lyases and carbohydrate esterases. Presenting a daunting challenge for future research, more than 190 upregulated genes are predicted to encode proteins of unknown function. Of these hypothetical proteins, approximately one-third featured predicted secretion signals, and 54 encoded proteins detected in extracellular filtrates. Our results affirm the importance of certain oxidative enzymes and, underscoring the complexity of lignocellulose degradation, also support an important role for many new proteins of unknown function.
Collapse
|
28
|
Stajic´ M, Vukojevic´ J, Duletic´-Lauševic´ S. Biology ofPleurotus eryngiiand role in biotechnological processes: a review. Crit Rev Biotechnol 2009; 29:55-66. [DOI: 10.1080/07388550802688821] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
29
|
Genome, transcriptome, and secretome analysis of wood decay fungus Postia placenta supports unique mechanisms of lignocellulose conversion. Proc Natl Acad Sci U S A 2009; 106:1954-9. [PMID: 19193860 DOI: 10.1073/pnas.0809575106] [Citation(s) in RCA: 369] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Brown-rot fungi such as Postia placenta are common inhabitants of forest ecosystems and are also largely responsible for the destructive decay of wooden structures. Rapid depolymerization of cellulose is a distinguishing feature of brown-rot, but the biochemical mechanisms and underlying genetics are poorly understood. Systematic examination of the P. placenta genome, transcriptome, and secretome revealed unique extracellular enzyme systems, including an unusual repertoire of extracellular glycoside hydrolases. Genes encoding exocellobiohydrolases and cellulose-binding domains, typical of cellulolytic microbes, are absent in this efficient cellulose-degrading fungus. When P. placenta was grown in medium containing cellulose as sole carbon source, transcripts corresponding to many hemicellulases and to a single putative beta-1-4 endoglucanase were expressed at high levels relative to glucose-grown cultures. These transcript profiles were confirmed by direct identification of peptides by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Also up-regulated during growth on cellulose medium were putative iron reductases, quinone reductase, and structurally divergent oxidases potentially involved in extracellular generation of Fe(II) and H(2)O(2). These observations are consistent with a biodegradative role for Fenton chemistry in which Fe(II) and H(2)O(2) react to form hydroxyl radicals, highly reactive oxidants capable of depolymerizing cellulose. The P. placenta genome resources provide unparalleled opportunities for investigating such unusual mechanisms of cellulose conversion. More broadly, the genome offers insight into the diversification of lignocellulose degrading mechanisms in fungi. Comparisons with the closely related white-rot fungus Phanerochaete chrysosporium support an evolutionary shift from white-rot to brown-rot during which the capacity for efficient depolymerization of lignin was lost.
Collapse
|
30
|
Romero E, Ferreira P, Martínez AT, Martínez MJ. New oxidase from Bjerkandera arthroconidial anamorph that oxidizes both phenolic and nonphenolic benzyl alcohols. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2008; 1794:689-97. [PMID: 19110079 DOI: 10.1016/j.bbapap.2008.11.013] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2008] [Revised: 11/17/2008] [Accepted: 11/18/2008] [Indexed: 11/15/2022]
Abstract
A new flavooxidase is described from a Bjerkandera arthroconidial anamorph. Its physicochemical characteristics, a monomeric enzyme containing non-covalently bound flavin adenine dinucleotide (FAD), and several catalytic properties, such as oxidation of aromatic and polyunsaturated aliphatic primary alcohols, are similar to those of Pleurotus eryngii aryl-alcohol oxidase (AAO). However, it also efficiently oxidizes phenolic benzyl and cinnamyl alcohols that are typical substrates of vanillyl-alcohol oxidase (VAO), a flavooxidase from a different family, characterized by its multimeric nature and presence of covalently-bound FAD. The enzyme also differs from P. eryngii AAO by having extremely high efficiency oxidizing chlorinated benzyl alcohols (1000-1500 s(-1) mM(-1)), a feature related to the different alcohol metabolites secreted by the Pleurotus and Bjerkandera species including chloroaromatics, and higher activity on aromatic aldehydes. What is even more intriguing is the fact that, the new oxidase is optimally active at pH 6.0 on both p-anisyl and vanillyl alcohols, suggesting a mechanism for phenolic benzyl alcohol oxidation that is different from that described in VAO, which proceeds via the substrate phenolate anion formed at basic pH. Based on the above properties, and its ADP-binding motif, partially detected after N-terminus sequencing, the new enzyme is classified as a member of the GMC (glucose-methanol-choline oxidase) oxidoreductase family oxidizing both AAO and VAO substrates.
Collapse
Affiliation(s)
- Elvira Romero
- Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, E-28040 Madrid, Spain
| | | | | | | |
Collapse
|
31
|
Munteanu FD, Ferreira P, Ruiz-Dueñas FJ, Martínez AT, Cavaco-Paulo A. Bioelectrochemical investigations of aryl-alcohol oxidase from Pleurotus eryngii. J Electroanal Chem (Lausanne) 2008. [DOI: 10.1016/j.jelechem.2008.02.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
32
|
Espagne E, Lespinet O, Malagnac F, Da Silva C, Jaillon O, Porcel BM, Couloux A, Aury JM, Ségurens B, Poulain J, Anthouard V, Grossetete S, Khalili H, Coppin E, Déquard-Chablat M, Picard M, Contamine V, Arnaise S, Bourdais A, Berteaux-Lecellier V, Gautheret D, de Vries RP, Battaglia E, Coutinho PM, Danchin EG, Henrissat B, Khoury RE, Sainsard-Chanet A, Boivin A, Pinan-Lucarré B, Sellem CH, Debuchy R, Wincker P, Weissenbach J, Silar P. The genome sequence of the model ascomycete fungus Podospora anserina. Genome Biol 2008; 9:R77. [PMID: 18460219 PMCID: PMC2441463 DOI: 10.1186/gb-2008-9-5-r77] [Citation(s) in RCA: 236] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2007] [Revised: 02/12/2008] [Accepted: 05/06/2008] [Indexed: 12/13/2022] Open
Abstract
A 10X draft sequence of Podospora anserina genome shows highly dynamic evolution since its divergence from Neurospora crassa. Background The dung-inhabiting ascomycete fungus Podospora anserina is a model used to study various aspects of eukaryotic and fungal biology, such as ageing, prions and sexual development. Results We present a 10X draft sequence of P. anserina genome, linked to the sequences of a large expressed sequence tag collection. Similar to higher eukaryotes, the P. anserina transcription/splicing machinery generates numerous non-conventional transcripts. Comparison of the P. anserina genome and orthologous gene set with the one of its close relatives, Neurospora crassa, shows that synteny is poorly conserved, the main result of evolution being gene shuffling in the same chromosome. The P. anserina genome contains fewer repeated sequences and has evolved new genes by duplication since its separation from N. crassa, despite the presence of the repeat induced point mutation mechanism that mutates duplicated sequences. We also provide evidence that frequent gene loss took place in the lineages leading to P. anserina and N. crassa. P. anserina contains a large and highly specialized set of genes involved in utilization of natural carbon sources commonly found in its natural biotope. It includes genes potentially involved in lignin degradation and efficient cellulose breakdown. Conclusion The features of the P. anserina genome indicate a highly dynamic evolution since the divergence of P. anserina and N. crassa, leading to the ability of the former to use specific complex carbon sources that match its needs in its natural biotope.
Collapse
Affiliation(s)
- Eric Espagne
- Univ Paris-Sud, Institut de Génétique et Microbiologie, UMR8621, 91405 Orsay cedex, France
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Feijoo G, Moreira MT, Álvarez P, Lú-Chau TA, Lema JM. Evaluation of the enzyme manganese peroxidase in an industrial sequence for the lignin oxidation and bleaching of eucalyptus kraft pulp. J Appl Polym Sci 2008. [DOI: 10.1002/app.28084] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
34
|
Kersten P, Cullen D. Extracellular oxidative systems of the lignin-degrading Basidiomycete Phanerochaete chrysosporium. Fungal Genet Biol 2007; 44:77-87. [PMID: 16971147 DOI: 10.1016/j.fgb.2006.07.007] [Citation(s) in RCA: 251] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2006] [Accepted: 07/20/2006] [Indexed: 11/17/2022]
Abstract
The US Department of Energy has assembled a high quality draft genome of Phanerochaete chrysosporium, a white rot Basidiomycete capable of completely degrading all major components of plant cell walls including cellulose, hemicellulose and lignin. Hundreds of sequences are predicted to encode extracellular enzymes including an impressive number of oxidative enzymes potentially involved in lignocellulose degradation. Herein, we summarize the number, organization, and expression of genes encoding peroxidases, copper radical oxidases, FAD-dependent oxidases, and multicopper oxidases. Possibly relevant to extracellular oxidative systems are genes involved in posttranslational processes and a large number of hypothetical proteins.
Collapse
Affiliation(s)
- Phil Kersten
- Forest Products Laboratory, USDA, One Gifford Pinchot Drive, Madison, WI 53705, USA
| | | |
Collapse
|
35
|
Ferreira P, Ruiz-Dueñas FJ, Martínez MJ, van Berkel WJH, Martínez AT. Site-directed mutagenesis of selected residues at the active site of aryl-alcohol oxidase, an H2O2-producing ligninolytic enzyme. FEBS J 2006; 273:4878-88. [PMID: 16999821 DOI: 10.1111/j.1742-4658.2006.05488.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Aryl-alcohol oxidase provides H(2)O(2) for lignin biodegradation, a key process for carbon recycling in land ecosystems that is also of great biotechnological interest. However, little is known of the structural determinants of the catalytic activity of this fungal flavoenzyme, which oxidizes a variety of polyunsaturated alcohols. Different alcohol substrates were docked on the aryl-alcohol oxidase molecular structure, and six amino acid residues surrounding the putative substrate-binding site were chosen for site-directed mutagenesis modification. Several Pleurotus eryngii aryl-alcohol oxidase variants were purified to homogeneity after heterologous expression in Emericella nidulans, and characterized in terms of their steady-state kinetic properties. Two histidine residues (His502 and His546) are strictly required for aryl-alcohol oxidase catalysis, as shown by the lack of activity of different variants. This fact, together with their location near the isoalloxazine ring of FAD, suggested a contribution to catalysis by alcohol activation, enabling its oxidation by flavin-adenine dinucleotide (FAD). The presence of two aromatic residues (at positions 92 and 501) is also required, as shown by the conserved activity of the Y92F and F501Y enzyme variants and the strongly impaired activity of Y92A and F501A. By contrast, a third aromatic residue (Tyr78) does not seem to be involved in catalysis. The kinetic and spectral properties of the Phe501 variants suggested that this residue could affect the FAD environment, modulating the catalytic rate of the enzyme. Finally, L315 affects the enzyme k(cat), although it is not located in the near vicinity of the cofactor. The present study provides the first evidence for the role of aryl-alcohol oxidase active site residues.
Collapse
Affiliation(s)
- Patricia Ferreira
- Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, E-28040 Madrid, Spain
| | | | | | | | | |
Collapse
|
36
|
Ferreira P, Medina M, Guillén F, Martínez M, Van Berkel W, Martínez Á. Spectral and catalytic properties of aryl-alcohol oxidase, a fungal flavoenzyme acting on polyunsaturated alcohols. Biochem J 2005; 389:731-8. [PMID: 15813702 PMCID: PMC1180723 DOI: 10.1042/bj20041903] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2004] [Revised: 03/11/2005] [Accepted: 04/06/2005] [Indexed: 11/17/2022]
Abstract
Spectral and catalytic properties of the flavoenzyme AAO (aryl-alcohol oxidase) from Pleurotus eryngii were investigated using recombinant enzyme. Unlike most flavoprotein oxidases, AAO does not thermodynamically stabilize a flavin semiquinone radical and forms no sulphite adduct. AAO catalyses the oxidative dehydrogenation of a wide range of unsaturated primary alcohols with hydrogen peroxide production. This differentiates the enzyme from VAO (vanillyl-alcohol oxidase), which is specific for phenolic compounds. Moreover, AAO is optimally active in the pH range of 5-6, whereas VAO has an optimum at pH 10. Kinetic studies showed that AAO is most active with p-anisyl alcohol and 2,4-hexadien-1-ol. AAO converts m- and p-chlorinated benzyl alcohols at a similar rate as it does benzyl alcohol, but introduction of a p-methoxy substituent in benzyl alcohol increases the reaction rate approx. 5-fold. AAO also exhibits low activity on aromatic aldehydes. 19F NMR analysis showed that fluorinated benzaldehydes are converted into the corresponding benzoic acids. Inhibition studies revealed that the AAO active site can bind a wide range of aromatic ligands, chavicol (4-allylphenol) and p-anisic (4-methoxybenzoic) acid being the best competitive inhibitors. Uncompetitive inhibition was observed with 4-methoxybenzylamine. The properties described above render AAO a unique oxidase. The possible mechanism of AAO binding and oxidation of substrates is discussed in the light of the results of the inhibition and kinetic studies.
Collapse
Affiliation(s)
- Patricia Ferreira
- *Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, E-28040 Madrid, Spain
| | - Milagros Medina
- †Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Ciencias, Universidad de Zaragoza, and Instituto de Biocomputación y Física de Sistemas Complejos (BIFI), Corona de Aragón 42, E-50009 Zaragoza, Spain
| | - Francisco Guillén
- *Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, E-28040 Madrid, Spain
| | - María Jesús Martínez
- *Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, E-28040 Madrid, Spain
| | - Willem J. H. Van Berkel
- ‡Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
| | - Ángel T. Martínez
- *Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, E-28040 Madrid, Spain
| |
Collapse
|
37
|
Ruiz-Dueñas FJ, Ferreira P, Martínez MJ, Martínez AT. In vitro activation, purification, and characterization of Escherichia coli expressed aryl-alcohol oxidase, a unique H2O2-producing enzyme. Protein Expr Purif 2005; 45:191-9. [PMID: 16039872 DOI: 10.1016/j.pep.2005.06.003] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2005] [Revised: 05/30/2005] [Accepted: 06/03/2005] [Indexed: 10/25/2022]
Abstract
Aryl-alcohol oxidase (AAO), a flavoenzyme with unique spectral and catalytic properties that provides H2O2 for fungal degradation of lignin, has been successfully activated in vitro after Escherichia coli expression. The recombinant AAO (AAO*) protein was recovered from inclusion bodies of E. coli W3110 transformed with pFLAG1 containing the aao cDNA from Pleurotus eryngii. Optimization of in vitro refolding yielded 75% active enzyme after incubation of AAO* protein (10 microg/ml) for 80 h (at 16 degrees C and pH 9) in the presence of glycerol (35%), urea (0.6 M), glutathione (GSSG/GSH molar ratio of 2), and FAD (0.08 mM). For large-scale production, the refolding volume was 15-fold reduced and over 45 mg of pure active AAO* was obtained per liter of E. coli culture after a single anion-exchange chromatographic step. Correct FAD binding and enzyme conformation were verified by UV-visible spectroscopy and circular dichroism. Although the three enzymes oxidized the same aromatic and aliphatic polyunsaturated primary alcohols, some differences in physicochemical properties, including lower pH and thermal stability, were observed when the activated enzyme was compared with fungal AAO from P. eryngii (wild enzyme) and Emericella nidulans (recombinant enzyme), which are probably related to the absence of glycosylation in the E. coli expressed AAO.
Collapse
|
38
|
Shimizu M, Kobayashi Y, Tanaka H, Wariishi H. Transportation mechanism for vanillin uptake through fungal plasma membrane. Appl Microbiol Biotechnol 2005; 68:673-9. [PMID: 15868144 DOI: 10.1007/s00253-005-1933-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2004] [Revised: 01/05/2005] [Accepted: 01/27/2005] [Indexed: 10/25/2022]
Abstract
Protoplasts of the basidiomycete, Fomitopsis palustris (formerly Tyromyces palustris), were utilized to study a function of the fungal plasma membrane. Fungal protoplasts exhibited metabolic activities as seen with intact mycelial cells. Furthermore, the uptake of certain compounds into the protoplast cells was quantitatively observed by using non-radioactive compounds. Vanillin was converted to vanillyl alcohol and vanillic acid as major products and to protocatechuic acid and 1,2,4-trihydroxybenzene as trace products by protoplasts prepared from F. palustris. Extracellular culture medium showed no activity responsible for the redox reactions of vanillin. Only vanillic acid was detected in the intracellular fraction of protoplasts. However, the addition of disulfiram, an aldehyde dehydrogenase inhibitor, caused an intracellular accumulation of vanillin, strongly suggesting that vanillin is taken up by the cell, followed by oxidation to vanillic acid. The addition of carbonylcyanide m-chlorophenylhydrazone, which dissipates the pH gradient across the plasma membrane, inhibited the uptake of either vanillin or vanillic acid into the cell. Thus, the fungus seems to possess transporter devices for both vanillin and vanillic acid for their uptake. Since vanillyl alcohol was only observed extracellularly, the reduction of vanillin was thought to be catalyzed by a membrane system.
Collapse
|
39
|
Phanerochaete chrysosporium Genomics. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/s1874-5334(05)80016-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
|
40
|
Teramoto H, Tanaka H, Wariishi H. Fungal cytochrome P450s catalyzing hydroxylation of substituted toluenes to form their hydroxymethyl derivatives. FEMS Microbiol Lett 2004. [DOI: 10.1111/j.1574-6968.2004.tb09541.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
|
41
|
Shah V, Nerud F. Lignin degrading system of white-rot fungi and its exploitation for dye decolorization. Can J Microbiol 2002; 48:857-70. [PMID: 12489775 DOI: 10.1139/w02-090] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
With global attention and research now focused on looking for the abatement of pollution, white-rot fungi is one of the hopes of the future. The lignin-degrading ability of these fungi have been the focus of attention for many years and have been exploited for a wide array of human benefits. This review highlights the various enzymes produced by white-rot fungi for lignin degradation, namely laccases, peroxidases, aryl alcohol oxidase, glyoxal oxidase, and pyranose oxidase. Also discussed are the various radicals and low molecular weight compounds that are being produced by white-rot fungi and its role in lignin degradation. A brief summary on the developments in research of decolorization of dyes using white-rot fungi has been made.
Collapse
Affiliation(s)
- Vishal Shah
- Department of Chemical Engineering, Chemistry and Material Science, Polytechnic University, 6 Metrotech Center, Brooklyn, NY 11201, USA.
| | | |
Collapse
|
42
|
Mason MG, Wilson MT, Ball A, Nicholls P. Oxygen reduction by cellobiose oxidoreductase: the role of the haem group. FEBS Lett 2002; 518:29-32. [PMID: 11997012 DOI: 10.1016/s0014-5793(02)02633-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We have used optical and electron paramagnetic spectroscopy to study the flavohaem enzyme cellobiose oxidoreductase (CBOR) from Phanerochaete chrysosporium. We have examined redox cycles of the enzyme in which the oxidation of cellobiose to cellobionolactone is coupled to the reduction of oxygen. During turnover flavin can reduce oxygen with one electron to produce superoxide or two electrons to produce hydrogen peroxide. Addition of superoxide dismutase significantly extended the time courses of these cycles, slowing the re-oxidation rate of both cofactors. Addition of catalase also affected the haem time course, but to a lesser extent. Experiments in which superoxide was generated in the reaction mixture showed that this radical greatly enhanced the rate of haem re-oxidation. From these results we propose a mechanism in which reactive oxygen species generation by CBOR flavin subsequently re-oxidises CBOR haem. We discuss this mechanism in relationship to the biological function of this enzyme, namely lignocellulose degradation.
Collapse
Affiliation(s)
- Maria G Mason
- Department of Biological Sciences, University of Essex, Wivenhoe Park, CO4 3SQ, Colchester, UK.
| | | | | | | |
Collapse
|
43
|
Sugimoto M, Tanabe M, Hataya M, Enokibara S, Duine JA, Kawai F. The first step in polyethylene glycol degradation by sphingomonads proceeds via a flavoprotein alcohol dehydrogenase containing flavin adenine dinucleotide. J Bacteriol 2001; 183:6694-8. [PMID: 11673442 PMCID: PMC95503 DOI: 10.1128/jb.183.22.6694-6698.2001] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Several Sphingomonas spp. utilize polyethylene glycols (PEGs) as a sole carbon and energy source, oxidative PEG degradation being initiated by a dye-linked dehydrogenase (PEG-DH) that oxidizes the terminal alcohol groups of the polymer chain. Purification and characterization of PEG-DH from Sphingomonas terrae revealed that the enzyme is membrane bound. The gene encoding this enzyme (pegA) was cloned, sequenced, and expressed in Escherichia coli. The purified recombinant enzyme was vulnerable to aggregation and inactivation, but this could be prevented by addition of detergent. It is as a homodimeric protein with a subunit molecular mass of 58.8 kDa, each subunit containing 1 noncovalently bound flavin adenine dinucleotide but not Fe or Zn. PEG-DH recognizes a broad variety of primary aliphatic and aromatic alcohols as substrates. Comparison with known sequences revealed that PEG-DH belongs to the group of glucose-methanol-choline (GMC) flavoprotein oxidoreductases and that it is a novel type of flavoprotein alcohol dehydrogenase related (percent identical amino acids) to other, so far uncharacterized bacterial, membrane-bound, dye-linked dehydrogenases: alcohol dehydrogenase from Pseudomonas oleovorans (46%); choline dehydrogenase from E. coli (40%); L-sorbose dehydrogenase from Gluconobacter oxydans (38%); and 4-nitrobenzyl alcohol dehydrogenase from a Pseudomonas species (35%).
Collapse
Affiliation(s)
- M Sugimoto
- Research Institute for Bioresources, Okayama University, Kurashiki, Okayama 710-0046, Japan
| | | | | | | | | | | |
Collapse
|
44
|
Dreveny I, Gruber K, Glieder A, Thompson A, Kratky C. The hydroxynitrile lyase from almond: a lyase that looks like an oxidoreductase. Structure 2001; 9:803-15. [PMID: 11566130 DOI: 10.1016/s0969-2126(01)00639-6] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
BACKGROUND Cyanogenesis is a defense process of several thousand plant species. Hydroxynitrile lyase, a key enzyme of this process, cleaves a cyanohydrin into hydrocyanic acid and the corresponding aldehyde or ketone. The reverse reaction constitutes an important tool in biocatalysis. Different classes of hydroxynitrile lyases have convergently evolved from FAD-dependent oxidoreductases, alpha/beta hydrolases, and alcohol dehydrogenases. The FAD-dependent hydroxynitrile lyases (FAD-HNLs) carry a flavin cofactor whose redox properties appear to be unimportant for catalysis. RESULTS We have determined the crystal structure of a 61 kDa hydroxynitrile lyase isoenzyme from Prunus amygdalus (PaHNL1) to 1.5 A resolution. Clear electron density originating from four glycosylation sites could be observed. As concerns the overall protein fold including the FAD cofactor, PaHNL1 belongs to the family of GMC oxidoreductases. The active site for the HNL reaction is probably at a very similar position as the active sites in homologous oxidases. CONCLUSIONS There is strong evidence from the structure and the reaction product that FAD-dependent hydroxynitrile lyases have evolved from an aryl alcohol oxidizing precursor. Since key residues implicated in oxidoreductase activity are also present in PaHNL1, it is not obvious why this enzyme shows no oxidase activity. Similarly, features proposed to be relevant for hydroxy-nitrile lyase activity in other hydroxynitrile lyases, i.e., a general base and a positive charge to stabilize the cyanide, are not obviously present in the putative active site of PaHNL1. Therefore, the reason for its HNL activity is far from being well understood at this point.
Collapse
Affiliation(s)
- I Dreveny
- Institut für Chemie, Karl-Franzens-Universität, Heinrichstrasse 28, Graz A-8010, Austria
| | | | | | | | | |
Collapse
|