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Xin Y, Shen C, Tang M, Guo Z, Shi Y, Gu Z, Shao J, Zhang L. Recreating the natural evolutionary trend in key microdomains provides an effective strategy for engineering of a thermomicrobial N-demethylase. J Biol Chem 2022; 298:101656. [PMID: 35124004 PMCID: PMC8892156 DOI: 10.1016/j.jbc.2022.101656] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/22/2022] [Accepted: 01/24/2022] [Indexed: 01/10/2023] Open
Abstract
N-demethylases have been reported to remove the methyl groups on primary or secondary amines, which could further affect the properties and functions of biomacromolecules or chemical compounds; however, the substrate scope and the robustness of N-demethylases have not been systematically investigated. Here we report the recreation of natural evolution in key microdomains of the Thermomicrobium roseum sarcosine oxidase (TrSOX), an N-demethylase with marked stability (melting temperature over 100 °C) and enantioselectivity, for enhanced substrate scope and catalytic efficiency on -C-N- bonds. We obtained the structure of TrSOX by crystallization and X-ray diffraction (XRD) for the initial framework. The natural evolution in the nonconserved residues of key microdomains—including the catalytic loop, coenzyme pocket, substrate pocket, and entrance site—was then identified using ancestral sequence reconstruction (ASR), and the substitutions that accrued during natural evolution were recreated by site-directed mutagenesis. The single and double substitution variants catalyzed the N-demethylation of N-methyl-L-amino acids up to 1800- and 6000-fold faster than the wild type, respectively. Additionally, these single substitution variants catalyzed the terminal N-demethylation of non-amino-acid compounds and the oxidation of the main chain -C-N- bond to a -C=N- bond in the nitrogen-containing heterocycle. Notably, these variants retained the enantioselectivity and stability of the initial framework. We conclude that the variants of TrSOX are of great potential use in N-methyl enantiomer resolution, main-chain Schiff base synthesis, and alkaloid modification or degradation.
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Lahham M, Jha S, Goj D, Macheroux P, Wallner S. The family of sarcosine oxidases: Same reaction, different products. Arch Biochem Biophys 2021; 704:108868. [PMID: 33812916 DOI: 10.1016/j.abb.2021.108868] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 03/26/2021] [Accepted: 03/27/2021] [Indexed: 12/11/2022]
Abstract
The subfamily of sarcosine oxidase is a set of enzymes within the larger family of amine oxidases. It is ubiquitously distributed among different kingdoms of life. The member enzymes catalyze the oxidization of an N-methyl amine bond of amino acids to yield unstable imine species that undergo subsequent spontaneous non-enzymatic reactions, forming an array of different products. These products range from demethylated simple species to complex alkaloids. The enzymes belonging to the sarcosine oxidase family, namely, monomeric and heterotetrameric sarcosine oxidase, l-pipecolate oxidase, N-methyltryptophan oxidase, NikD, l-proline dehydrogenase, FsqB, fructosamine oxidase and saccharopine oxidase have unique features differentiating them from other amine oxidases. This review highlights the key attributes of the sarcosine oxidase family enzymes, in terms of their substrate binding motif, type of oxidation reaction mediated and FAD regeneration, to define the boundaries of this group and demarcate these enzymes from other amine oxidase families.
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Affiliation(s)
- Majd Lahham
- Institute of Biochemistry, Graz University of Technology, NAWI Graz, Graz, Austria; Department of Biochemistry and Microbiology, Aljazeera Private University, Ghabagheb, Syria
| | - Shalinee Jha
- Institute of Biochemistry, Graz University of Technology, NAWI Graz, Graz, Austria
| | - Dominic Goj
- Institute of Biochemistry, Graz University of Technology, NAWI Graz, Graz, Austria
| | - Peter Macheroux
- Institute of Biochemistry, Graz University of Technology, NAWI Graz, Graz, Austria
| | - Silvia Wallner
- Institute of Biochemistry, Graz University of Technology, NAWI Graz, Graz, Austria.
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3
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Soluble expression of Thermomicrobium roseum sarcosine oxidase and characterization of N-demethylation activity. MOLECULAR CATALYSIS 2019. [DOI: 10.1016/j.mcat.2018.12.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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4
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Lahham M, Pavkov-Keller T, Fuchs M, Niederhauser J, Chalhoub G, Daniel B, Kroutil W, Gruber K, Macheroux P. Oxidative cyclization of N-methyl-dopa by a fungal flavoenzyme of the amine oxidase family. J Biol Chem 2018; 293:17021-17032. [PMID: 30194285 PMCID: PMC6222107 DOI: 10.1074/jbc.ra118.004227] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 09/06/2018] [Indexed: 11/19/2022] Open
Abstract
Flavin-dependent enzymes catalyze many oxidations, including formation of ring structures in natural products. The gene cluster for biosynthesis of fumisoquins, secondary metabolites structurally related to isoquinolines, in the filamentous fungus Aspergillus fumigatus harbors a gene that encodes a flavoprotein of the amine oxidase family, termed fsqB (fumisoquin biosynthesis gene B). This enzyme catalyzes an oxidative ring closure reaction that leads to the formation of isoquinoline products. This reaction is reminiscent of the oxidative cyclization reported for berberine bridge enzyme and tetrahydrocannabinol synthase. Despite these similarities, amine oxidases and berberine bridge enzyme–like enzymes possess distinct structural properties, prompting us to investigate the structure–function relationships of FsqB. Here, we report the recombinant production and purification of FsqB, elucidation of its crystal structure, and kinetic analysis employing five putative substrates. The crystal structure at 2.6 Å resolution revealed that FsqB is a member of the amine oxidase family with a covalently bound FAD cofactor. N-methyl-dopa was the best substrate for FsqB and was completely converted to the cyclic isoquinoline product. The absence of the meta-hydroxyl group, as e.g. in l-N-methyl-tyrosine, resulted in a 25-fold lower rate of reduction and the formation of the demethylated product l-tyrosine, instead of a cyclic product. Surprisingly, FsqB did not accept the d-stereoisomer of N-methyltyrosine, in contrast to N-methyl-dopa, for which both stereoisomers were oxidized with similar rates. On the basis of the crystal structure and docking calculations, we postulate a substrate-dependent population of distinct binding modes that rationalizes stereospecific oxidation in the FsqB active site.
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Affiliation(s)
- Majd Lahham
- From the Institutes of Biochemistry, Graz University of Technology, Petersgasse 12/II, 8010 Graz
| | - Tea Pavkov-Keller
- the Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, and
| | - Michael Fuchs
- the Institute of Chemistry, University of Graz, Heinrichstrasse 28/2, 8010 Graz, Austria
| | - Johannes Niederhauser
- From the Institutes of Biochemistry, Graz University of Technology, Petersgasse 12/II, 8010 Graz
| | - Gabriel Chalhoub
- From the Institutes of Biochemistry, Graz University of Technology, Petersgasse 12/II, 8010 Graz
| | - Bastian Daniel
- From the Institutes of Biochemistry, Graz University of Technology, Petersgasse 12/II, 8010 Graz
| | - Wolfgang Kroutil
- the Institute of Chemistry, University of Graz, Heinrichstrasse 28/2, 8010 Graz, Austria
| | - Karl Gruber
- the Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, and
| | - Peter Macheroux
- From the Institutes of Biochemistry, Graz University of Technology, Petersgasse 12/II, 8010 Graz,
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5
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Preparation, reconstruction, and characterization of a predicted Thermomicrobium roseum sarcosine oxidase. MOLECULAR CATALYSIS 2018. [DOI: 10.1016/j.mcat.2018.06.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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6
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Ouedraogo D, Souffrant M, Vasquez S, Hamelberg D, Gadda G. Importance of Loop L1 Dynamics for Substrate Capture and Catalysis in Pseudomonas aeruginosa d-Arginine Dehydrogenase. Biochemistry 2017; 56:2477-2487. [DOI: 10.1021/acs.biochem.7b00098] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Daniel Ouedraogo
- Department
of Chemistry, ‡Department of Biology, §Center for Diagnostics and Therapeutics, and ∥Center for Biotechnology
and Drug Design, Georgia State University, Atlanta, Georgia 30302, United States
| | - Michael Souffrant
- Department
of Chemistry, ‡Department of Biology, §Center for Diagnostics and Therapeutics, and ∥Center for Biotechnology
and Drug Design, Georgia State University, Atlanta, Georgia 30302, United States
| | - Sheena Vasquez
- Department
of Chemistry, ‡Department of Biology, §Center for Diagnostics and Therapeutics, and ∥Center for Biotechnology
and Drug Design, Georgia State University, Atlanta, Georgia 30302, United States
| | - Donald Hamelberg
- Department
of Chemistry, ‡Department of Biology, §Center for Diagnostics and Therapeutics, and ∥Center for Biotechnology
and Drug Design, Georgia State University, Atlanta, Georgia 30302, United States
| | - Giovanni Gadda
- Department
of Chemistry, ‡Department of Biology, §Center for Diagnostics and Therapeutics, and ∥Center for Biotechnology
and Drug Design, Georgia State University, Atlanta, Georgia 30302, United States
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7
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Romero-Rivera A, Garcia-Borràs M, Osuna S. Computational tools for the evaluation of laboratory-engineered biocatalysts. Chem Commun (Camb) 2016; 53:284-297. [PMID: 27812570 PMCID: PMC5310519 DOI: 10.1039/c6cc06055b] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 09/06/2016] [Indexed: 12/18/2022]
Abstract
Biocatalysis is based on the application of natural catalysts for new purposes, for which enzymes were not designed. Although the first examples of biocatalysis were reported more than a century ago, biocatalysis was revolutionized after the discovery of an in vitro version of Darwinian evolution called Directed Evolution (DE). Despite the recent advances in the field, major challenges remain to be addressed. Currently, the best experimental approach consists of creating multiple mutations simultaneously while limiting the choices using statistical methods. Still, tens of thousands of variants need to be tested experimentally, and little information is available on how these mutations lead to enhanced enzyme proficiency. This review aims to provide a brief description of the available computational techniques to unveil the molecular basis of improved catalysis achieved by DE. An overview of the strengths and weaknesses of current computational strategies is explored with some recent representative examples. The understanding of how this powerful technique is able to obtain highly active variants is important for the future development of more robust computational methods to predict amino-acid changes needed for activity.
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Affiliation(s)
- Adrian Romero-Rivera
- Institut de Química Computacional i Catàlisi and Departament de Química Universitat de Girona, Campus Montilivi, 17071 Girona, Catalonia, Spain.
| | - Marc Garcia-Borràs
- Department of Chemistry and Biochemistry, University of California, 607 Charles E. Young Drive, Los Angeles, California 90095, USA
| | - Sílvia Osuna
- Institut de Química Computacional i Catàlisi and Departament de Química Universitat de Girona, Campus Montilivi, 17071 Girona, Catalonia, Spain.
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Angiulli G, Lantella A, Forte E, Angelucci F, Colotti G, Ilari A, Malatesta F. Leishmania infantum trypanothione reductase is a promiscuous enzyme carrying an NADPH:O2 oxidoreductase activity shared by glutathione reductase. Biochim Biophys Acta Gen Subj 2015; 1850:1891-7. [PMID: 26033467 DOI: 10.1016/j.bbagen.2015.05.022] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 05/05/2015] [Accepted: 05/27/2015] [Indexed: 01/01/2023]
Abstract
BACKGROUND Leishmania infantum is a protozoan of the trypanosomatid family causing visceral leishmaniasis. Leishmania parasites are transmitted by the bite of phlebotomine sand flies to the human host and are phagocyted by macrophages. The parasites synthesize N1-N8-bis(glutationyl)-spermidine (trypanothione, TS2), which furnishes electrons to the tryparedoxin-tryparedoxin peroxidase couple to reduce the reactive oxygen species produced by macrophages. Trypanothione is kept reduced by trypanothione reductase (TR), a FAD-containing enzyme essential for parasite survival. METHODS The enzymatic activity has been studied by stopped-flow, absorption spectroscopy, and amperometric measurements. RESULTS The study reported here demonstrates that the steady-state parameters change as a function of the order of substrates addition to the TR-containing solution. In particular, when the reaction is carried out by adding NADPH to a solution containing the enzyme and trypanothione, the KM for NADPH decreases six times compared to the value obtained by adding TS2 as last reagent to start the reaction (1.9 vs. 12μM). More importantly, we demonstrate that TR is able to catalyze the oxidation of NADPH also in the absence of trypanothione. Thus, TR catalyzes the reduction of O2 to water through the sequential formation of C(4a)-(hydro)peroxyflavin and sulfenic acid intermediates. This NADPH:O2 oxidoreductase activity is shared by Saccharomyces cerevisiae glutathione reductase (GR). CONCLUSIONS TR and GR, in the absence of their physiological substrates, may catalyze the electron transfer reaction from NADPH to molecular oxygen to yield water. GENERAL SIGNIFICANCE TR and GR are promiscuous enzymes.
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Affiliation(s)
- Gabriella Angiulli
- Department of Biochemical Sciences "Alessandro Rossi Fanelli", Sapienza University of Rome, Rome Italy
| | - Antonella Lantella
- Department of Biochemical Sciences "Alessandro Rossi Fanelli", Sapienza University of Rome, Rome Italy
| | - Elena Forte
- Department of Biochemical Sciences "Alessandro Rossi Fanelli", Sapienza University of Rome, Rome Italy
| | - Francesco Angelucci
- Dipartimento di Medicina Clinica, Sanità Pubblica, Scienze della Vita e dell'Ambiente, University of L'Aquila, L'Aquila, Italy
| | - Gianni Colotti
- CNR-Institute of Molecular Biology and Pathology, c/o Department of Biochemical Sciences, Sapienza University of Rome, Rome, Italy
| | - Andrea Ilari
- CNR-Institute of Molecular Biology and Pathology, c/o Department of Biochemical Sciences, Sapienza University of Rome, Rome, Italy.
| | - Francesco Malatesta
- Department of Biochemical Sciences "Alessandro Rossi Fanelli", Sapienza University of Rome, Rome Italy.
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9
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Karasulu B, Thiel W. Amine Oxidation Mediated by N-Methyltryptophan Oxidase: Computational Insights into the Mechanism, Role of Active-Site Residues, and Covalent Flavin Binding. ACS Catal 2015. [DOI: 10.1021/cs501694q] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Bora Karasulu
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz
1, 45470 Mülheim, Germany
| | - Walter Thiel
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz
1, 45470 Mülheim, Germany
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10
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Fitzpatrick PF. Combining solvent isotope effects with substrate isotope effects in mechanistic studies of alcohol and amine oxidation by enzymes. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2014; 1854:1746-55. [PMID: 25448013 DOI: 10.1016/j.bbapap.2014.10.020] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Revised: 10/17/2014] [Accepted: 10/20/2014] [Indexed: 10/24/2022]
Abstract
Oxidation of alcohols and amines is catalyzed by multiple families of flavin- and pyridine nucleotide-dependent enzymes. Measurement of solvent isotope effects provides a unique mechanistic probe of the timing of the cleavage of the OH and NH bonds, necessary information for a complete description of the catalytic mechanism. The inherent ambiguities in interpretation of solvent isotope effects can be significantly decreased if isotope effects arising from isotopically labeled substrates are measured in combination with solvent isotope effects. The application of combined solvent and substrate (mainly deuterium) isotope effects to multiple enzymes is described here to illustrate the range of mechanistic insights that such an approach can provide. This article is part of a Special Issue entitled: Enzyme Transition States from Theory and Experiment.
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Affiliation(s)
- Paul F Fitzpatrick
- Department of Biochemistry, University of Texas Health Science Center, San Antonio, TX 78212, USA.
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11
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Gannavaram S, Sirin S, Sherman W, Gadda G. Mechanistic and Computational Studies of the Reductive Half-Reaction of Tyrosine to Phenylalanine Active Site Variants of d-Arginine Dehydrogenase. Biochemistry 2014; 53:6574-83. [PMID: 25243743 DOI: 10.1021/bi500917q] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Sarah Sirin
- Schrödinger, LLC, 120 West 45st Street, New York, New York 10036, United States
| | - Woody Sherman
- Schrödinger, LLC, 120 West 45st Street, New York, New York 10036, United States
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12
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Kopacz MM, Heuts DPHM, Fraaije MW. Kinetic mechanism of putrescine oxidase from Rhodococcus erythropolis. FEBS J 2014; 281:4384-93. [PMID: 25060191 DOI: 10.1111/febs.12945] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Revised: 07/01/2014] [Accepted: 07/23/2014] [Indexed: 01/14/2023]
Abstract
Putrescine oxidase from Rhodococcus erythropolis (PuO) is a flavin-containing amine oxidase from the monoamine oxidase family that performs oxidative deamination of aliphatic diamines. In this study we report pre-steady-state kinetic analyses of the enzyme with the use of single- and double-mixing stopped-flow spectroscopy and putrescine as a substrate. During the fast and irreversible reductive half-reaction no radical intermediates were observed, suggesting a direct hydride transfer from the substrate to the FAD. The rate constant of flavin reoxidation depends on the ligand binding; when the imine product was bound to the enzyme the rate constant was higher than with free enzyme species. Similar results were obtained with product-mimicking ligands and this indicates that a ternary complex is formed during catalysis. The obtained kinetic data were used together with steady-state rate equations derived for ping-pong, ordered sequential and bifurcated mechanisms to explore which mechanism is operative. The integrated analysis revealed that PuO employs a bifurcated mechanism due to comparable rate constants of product release from the reduced enzyme and reoxidation of the reduced enzyme-product complex.
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Affiliation(s)
- Malgorzata M Kopacz
- Molecular Enzymology Group, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, The Netherlands
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13
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Li ZW, Shen YH, Xiang ZH, Zhang Z. Pathogen-origin horizontally transferred genes contribute to the evolution of Lepidopteran insects. BMC Evol Biol 2011; 11:356. [PMID: 22151541 PMCID: PMC3252269 DOI: 10.1186/1471-2148-11-356] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Accepted: 12/12/2011] [Indexed: 12/31/2022] Open
Abstract
Background Horizontal gene transfer (HGT), a source of genetic variation, is generally considered to facilitate hosts' adaptability to environments. However, convincing evidence supporting the significant contribution of the transferred genes to the evolution of metazoan recipients is rare. Results In this study, based on sequence data accumulated to date, we used a unified method consisting of similarity search and phylogenetic analysis to detect horizontally transferred genes (HTGs) between prokaryotes and five insect species including Drosophila melanogaster, Anopheles gambiae, Bombyx mori, Tribolium castaneum and Apis mellifera. Unexpectedly, the candidate HTGs were not detected in D. melanogaster, An. gambiae and T. castaneum, and 79 genes in Ap. mellifera sieved by the same method were considered as contamination based on other information. Consequently, 14 types of 22 HTGs were detected only in the silkworm. Additionally, 13 types of the detected silkworm HTGs share homologous sequences in species of other Lepidopteran superfamilies, suggesting that the majority of these HTGs were derived from ancient transfer events before the radiation of Ditrysia clade. On the basis of phylogenetic topologies and BLAST search results, donor bacteria of these genes were inferred, respectively. At least half of the predicted donor organisms may be entomopathogenic bacteria. The predicted biochemical functions of these genes include four categories: glycosyl hydrolase family, oxidoreductase family, amino acid metabolism, and others. Conclusions The products of HTGs detected in this study may take part in comprehensive physiological metabolism. These genes potentially contributed to functional innovation and adaptability of Lepidopteran hosts in their ancient lineages associated with the diversification of angiosperms. Importantly, our results imply that pathogens may be advantageous to the subsistence and prosperity of hosts through effective HGT events at a large evolutionary scale.
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Affiliation(s)
- Zi-Wen Li
- The Key Sericultural Laboratory of Agricultural Ministry, Southwest University, Chongqing 400715, China
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14
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Zhu B, Lou MM, Xie GL, Zhang GQ, Zhou XP, Li B, Jin GL. Horizontal gene transfer in silkworm, Bombyx mori. BMC Genomics 2011; 12:248. [PMID: 21595916 PMCID: PMC3116507 DOI: 10.1186/1471-2164-12-248] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2010] [Accepted: 05/19/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The domesticated silkworm, Bombyx mori, is the model insect for the order Lepidoptera, has economically important values, and has gained some representative behavioral characteristics compared to its wild ancestor. The genome of B. mori has been fully sequenced while function analysis of BmChi-h and BmSuc1 genes revealed that horizontal gene transfer (HGT) maybe bestow a clear selective advantage to B. mori. However, the role of HGT in the evolutionary history of B. mori is largely unexplored. In this study, we compare the whole genome of B. mori with those of 382 prokaryotic and eukaryotic species to investigate the potential HGTs. RESULTS Ten candidate HGT events were defined in B. mori by comprehensive sequence analysis using Maximum Likelihood and Bayesian method combining with EST checking. Phylogenetic analysis of the candidate HGT genes suggested that one HGT was plant-to- B. mori transfer while nine were bacteria-to- B. mori transfer. Furthermore, functional analysis based on expression, coexpression and related literature searching revealed that several HGT candidate genes have added important characters, such as resistance to pathogen, to B. mori. CONCLUSIONS Results from this study clearly demonstrated that HGTs play an important role in the evolution of B. mori although the number of HGT events in B. mori is in general smaller than those of microbes and other insects. In particular, interdomain HGTs in B. mori may give rise to functional, persistent, and possibly evolutionarily significant new genes.
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Affiliation(s)
- Bo Zhu
- State Key Laboratory of Rice Biology and Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Ministry of Agriculture, Institute of Biotechnology, Zhejiang University, Hangzhou 310029, China
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15
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Bruckner RC, Winans J, Jorns MS. Pleiotropic impact of a single lysine mutation on biosynthesis of and catalysis by N-methyltryptophan oxidase. Biochemistry 2011; 50:4949-62. [PMID: 21526853 DOI: 10.1021/bi200349m] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
N-Methyltryptophan oxidase (MTOX) contains covalently bound FAD. N-Methyltryptophan binds in a cavity above the re face of the flavin ring. Lys259 is located above the opposite, si face. Replacement of Lys259 with Gln, Ala, or Met blocks (>95%) covalent flavin incorporation in vivo. The mutant apoproteins can be reconstituted with FAD. Apparent turnover rates (k(cat,app)) of the reconstituted enzymes are ~2500-fold slower than those of wild-type MTOX. Wild-type MTOX forms a charge-transfer E(ox)·S complex with the redox-active anionic form of NMT. The E(ox)·S complex formed with Lys259Gln does not exhibit a charge-transfer band and is converted to a reduced enzyme·imine complex (EH(2)·P) at a rate 60-fold slower than that of wild-type MTOX. The mutant EH(2)·P complex contains the imine zwitterion and exhibits a charge-transfer band, a feature not observed with the wild-type EH(2)·P complex. Reaction of reduced Lys259Gln with oxygen is 2500-fold slower than that of reduced wild-type MTOX. The latter reaction is unaffected by the presence of bound product. Dissociation of the wild-type EH(2)·P complex is 80-fold slower than k(cat). The mutant EH(2)·P complex dissociates 15-fold faster than k(cat,app). Consequently, EH(2)·P and free EH(2) are the species that react with oxygen during turnover of the wild-type and mutant enzyme, respectively. The results show that (i) Lys259 is the site of oxygen activation in MTOX and also plays a role in holoenzyme biosynthesis and N-methyltryptophan oxidation and (ii) MTOX contains separate active sites for N-methyltryptophan oxidation and oxygen reduction on opposite faces of the flavin ring.
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Affiliation(s)
- Robert C Bruckner
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, USA
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16
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Jorns MS, Chen ZW, Mathews FS. Structural characterization of mutations at the oxygen activation site in monomeric sarcosine oxidase . Biochemistry 2010; 49:3631-9. [PMID: 20353187 DOI: 10.1021/bi100160j] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Oxygen reduction and sarcosine oxidation in monomeric sarcosine oxidase (MSOX) occur at separate sites above the si- and re-faces, respectively, of the flavin ring. Mutagenesis studies implicate Lys265 as the oxygen activation site. Substitution of Lys265 with a neutral (Met, Gln, or Ala) or basic (Arg) residue results in an approximately 10(4)- or 250-fold decrease, respectively, in the reaction rate. The overall structure of MSOX and residue conformation in the sarcosine binding cavity are unaffected by replacement of Lys265 with Met or Arg. The side chain of Met265 exhibits the same configuration in each molecule of Lys265Met crystals and is nearly congruent with Lys265 in wild-type MSOX. The side chain of Arg265 is, however, dramatically shifted ( approximately 4-5 A) compared with Lys265, points in the opposite direction, and exhibits significant conformational variability between molecules of the same crystal. The major species in solutions of Lys265Arg is likely to contain a "flipped-out" Arg265 and exhibit negligible oxygen activation, similar to Lys265Met. The 400-fold higher oxygen reactivity observed with Lys265Arg is attributed to a minor (<1%) "flipped-in" Arg265 conformer whose oxygen reactivity is similar to that of wild-type MSOX. A structural water (WAT1), found above the si-face of the flavin ring in all previously determined MSOX structures, is part of an apparent proton relay system that extends from FAD N(5) to bulk solvent. WAT1 is strikingly absent in Lys265Met and Lys265Arg, a feature that may account for the apparent kinetic stabilization of a reductive half-reaction intermediate that is detectable with the mutants but not wild-type MSOX.
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Affiliation(s)
- Marilyn Schuman Jorns
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, USA.
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17
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Oxidation of amines by flavoproteins. Arch Biochem Biophys 2009; 493:13-25. [PMID: 19651103 DOI: 10.1016/j.abb.2009.07.019] [Citation(s) in RCA: 166] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2009] [Revised: 07/27/2009] [Accepted: 07/29/2009] [Indexed: 11/21/2022]
Abstract
Many flavoproteins catalyze the oxidation of primary and secondary amines, with the transfer of a hydride equivalent from a carbon-nitrogen bond to the flavin cofactor. Most of these amine oxidases can be classified into two structural families, the D-amino acid oxidase/sarcosine oxidase family and the monoamine oxidase family. This review discusses the present understanding of the mechanisms of amine and amino acid oxidation by flavoproteins, focusing on these two structural families.
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Tralau T, Lafite P, Levy C, Combe JP, Scrutton NS, Leys D. An internal reaction chamber in dimethylglycine oxidase provides efficient protection from exposure to toxic formaldehyde. J Biol Chem 2009; 284:17826-34. [PMID: 19369258 PMCID: PMC2719421 DOI: 10.1074/jbc.m109.006262] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2009] [Revised: 04/09/2009] [Indexed: 11/06/2022] Open
Abstract
We report a synthetic biology approach to demonstrate substrate channeling in an unusual bifunctional flavoprotein dimethylglycine oxidase. The catabolism of dimethylglycine through methyl group oxidation can potentially liberate toxic formaldehyde, a problem common to many amine oxidases and dehydrogenases. Using a novel synthetic in vivo reporter system for cellular formaldehyde, we found that the oxidation of dimethylglycine is coupled to the synthesis of 5,10-methylenetetrahydrofolate through an unusual substrate channeling mechanism. We also showed that uncoupling of the active sites could be achieved by mutagenesis or deletion of the 5,10-methylenetetrahydrofolate synthase site and that this leads to accumulation of intracellular formaldehyde. Channeling occurs by nonbiased diffusion of the labile intermediate through a large solvent cavity connecting both active sites. This central "reaction chamber" is created by a modular protein architecture that appears primitive when compared with the sophisticated design of other paradigm substrate-channeling enzymes. The evolutionary origins of the latter were likely similar to dimethylglycine oxidase. This work demonstrates the utility of synthetic biology approaches to the study of enzyme mechanisms in vivo and points to novel channeling mechanisms that protect the cell milieu from potentially toxic reaction products.
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Affiliation(s)
- Tewes Tralau
- From the Manchester Interdisciplinary Biocentre, Faculty of Life Sciences, University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - Pierre Lafite
- From the Manchester Interdisciplinary Biocentre, Faculty of Life Sciences, University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - Colin Levy
- From the Manchester Interdisciplinary Biocentre, Faculty of Life Sciences, University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - John P. Combe
- From the Manchester Interdisciplinary Biocentre, Faculty of Life Sciences, University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - Nigel S. Scrutton
- From the Manchester Interdisciplinary Biocentre, Faculty of Life Sciences, University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - David Leys
- From the Manchester Interdisciplinary Biocentre, Faculty of Life Sciences, University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
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Heuts DPHM, Scrutton NS, McIntire WS, Fraaije MW. What's in a covalent bond? On the role and formation of covalently bound flavin cofactors. FEBS J 2009; 276:3405-27. [PMID: 19438712 DOI: 10.1111/j.1742-4658.2009.07053.x] [Citation(s) in RCA: 140] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Many enzymes use one or more cofactors, such as biotin, heme, or flavin. These cofactors may be bound to the enzyme in a noncovalent or covalent manner. Although most flavoproteins contain a noncovalently bound flavin cofactor (FMN or FAD), a large number have these cofactors covalently linked to the polypeptide chain. Most covalent flavin-protein linkages involve a single cofactor attachment via a histidyl, tyrosyl, cysteinyl or threonyl linkage. However, some flavoproteins contain a flavin that is tethered to two amino acids. In the last decade, many studies have focused on elucidating the mechanism(s) of covalent flavin incorporation (flavinylation) and the possible role(s) of covalent protein-flavin bonds. These endeavors have revealed that covalent flavinylation is a post-translational and self-catalytic process. This review presents an overview of the known types of covalent flavin bonds and the proposed mechanisms and roles of covalent flavinylation.
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Affiliation(s)
- Dominic P H M Heuts
- Laboratory of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, The Netherlands
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Zhao G, Bruckner RC, Jorns MS. Identification of the oxygen activation site in monomeric sarcosine oxidase: role of Lys265 in catalysis. Biochemistry 2008; 47:9124-35. [PMID: 18693755 PMCID: PMC2764408 DOI: 10.1021/bi8008642] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Monomeric sarcosine oxidase (MSOX) catalyzes the oxidation of N-methylglycine and contains covalently bound FAD that is hydrogen bonded at position N(5) to Lys265 via a bridging water. Lys265 is absent in the homologous but oxygen-unreactive FAD site in heterotetrameric sarcosine oxidase. Isolated preparations of Lys265 mutants contain little or no flavin but can be covalently reconstituted with FAD. Mutation of Lys265 to a neutral residue (Ala, Gln, Met) causes a 6000- to 9000-fold decrease in apparent turnover rate whereas a 170-fold decrease is found with Lys265Arg. Substitution of Lys265 with Met or Arg causes only a modest decrease in the rate of sarcosine oxidation (9.0- or 3.8-fold, respectively), as judged by reductive half-reaction studies which show that the reactions proceed via an initial enzyme.sarcosine charge transfer complex and a novel spectral intermediate not detected with wild-type MSOX. Oxidation of reduced wild-type MSOX (k = 2.83 x 10(5) M(-1) s(-1)) is more than 1000-fold faster than observed for the reaction of oxygen with free reduced flavin. Mutation of Lys265 to a neutral residue causes a dramatic 8000-fold decrease in oxygen reactivity whereas a 250-fold decrease is observed with Lys265Arg. The results provide definitive evidence for Lys265 as the site of oxygen activation and show that a single positively charged amino acid residue is entirely responsible for the rate acceleration observed with wild-type enzyme. Significantly, the active sites for sarcosine oxidation and oxygen reduction are located on opposite faces of the flavin ring.
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Affiliation(s)
- Guohua Zhao
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, USA
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