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Matsuda K, Nakahara Y, Choirunnisa AR, Arima K, Wakimoto T. Phylogeny-guided Characterization of Bacterial Hydrazine Biosynthesis Mediated by Cupin/methionyl tRNA Synthetase-like Enzymes. Chembiochem 2024; 25:e202300838. [PMID: 38403952 DOI: 10.1002/cbic.202300838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 01/27/2024] [Accepted: 02/25/2024] [Indexed: 02/27/2024]
Abstract
Cupin/methionyl-tRNA synthetase (MetRS)-like didomain enzymes catalyze nitrogen-nitrogen (N-N) bond formation between Nω-hydroxylamines and amino acids to generate hydrazines, key biosynthetic intermediates of various natural products containing N-N bonds. While the combination of these two building blocks leads to the creation of diverse hydrazine products, the full extent of their structural diversity remains largely unknown. To explore this, we herein conducted phylogeny-guided genome-mining of related hydrazine biosynthetic pathways consisting of two enzymes: flavin-dependent Nω-hydroxylating monooxygenases (NMOs) that produce Nω-hydroxylamine precursors and cupin/MetRS-like enzymes that couple the Nω-hydroxylamines with amino acids via N-N bonds. A phylogenetic analysis identified the largely unexplored sequence spaces of these enzyme families. The biochemical characterization of NMOs demonstrated their capabilities to produce various Nω-hydroxylamines, including those previously not known as precursors of N-N bonds. Furthermore, the characterization of cupin/MetRS-like enzymes identified five new hydrazine products with novel combinations of building blocks, including one containing non-amino acid building blocks: 1,3-diaminopropane and putrescine. This study substantially expanded the variety of N-N bond forming pathways mediated by cupin/MetRS-like enzymes.
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Affiliation(s)
- Kenichi Matsuda
- Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12, Nishi 6, Kita-ku, Sapporo, 060-0812, Japan
| | - Yuto Nakahara
- Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12, Nishi 6, Kita-ku, Sapporo, 060-0812, Japan
| | - Atina Rizkiya Choirunnisa
- Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12, Nishi 6, Kita-ku, Sapporo, 060-0812, Japan
| | - Kuga Arima
- Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12, Nishi 6, Kita-ku, Sapporo, 060-0812, Japan
| | - Toshiyuki Wakimoto
- Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12, Nishi 6, Kita-ku, Sapporo, 060-0812, Japan
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2
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Zhao H, Ren Y, Xie F, Dai H, Liu H, Fu C, Müller R. Nobachelins, new siderophores from Nocardiopsisbaichengensis protecting Caenorhabditiselegans from Pseudomonasaeruginosa infection. Synth Syst Biotechnol 2023; 8:640-646. [PMID: 37927895 PMCID: PMC10622741 DOI: 10.1016/j.synbio.2023.09.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 09/17/2023] [Accepted: 09/21/2023] [Indexed: 11/07/2023] Open
Abstract
The biosynthetic potential of actinobacteria to produce novel natural products is still regarded as immense. In this paper, we correlated a cryptic biosynthetic gene cluster to chemical molecules by genome mining and chemical analyses, leading to the discovery of a new group of catecholate-hydroxamate siderophores, nobachelins, from Nocardiopsisbaichengensis DSM 44845. Nobachelin biosynthesis genes are conserved in several bacteria from the family Nocardiopsidaceae. Structurally, nobachelins feature fatty-acylated hydroxy-ornithine and a rare chlorinated catecholate group. Intriguingly, nobachelins rescued Caenorhabditiselegans from Pseudomonasaeruginosa-mediated killing.
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Affiliation(s)
- Haowen Zhao
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), and Department of Pharmacy, Saarland University, 66123, Saarbrücken, Germany
- Helmholtz International Lab for Anti-Infectives, Helmholtz Center for Infection Research, 38124, Braunschweig, Germany
- Institute of Marine Biology and Pharmacology, Ocean College, Zhejiang University, 316021, Zhoushan, China
| | - Yuhao Ren
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), and Department of Pharmacy, Saarland University, 66123, Saarbrücken, Germany
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, 201203, Shanghai, China
| | - Feng Xie
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), and Department of Pharmacy, Saarland University, 66123, Saarbrücken, Germany
| | - Huanqin Dai
- State Key Lab of Mycology, Institute of Microbiology, Chinese Academy of Sciences, 100101, Beijing, China
| | - Hongwei Liu
- State Key Lab of Mycology, Institute of Microbiology, Chinese Academy of Sciences, 100101, Beijing, China
| | - Chengzhang Fu
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), and Department of Pharmacy, Saarland University, 66123, Saarbrücken, Germany
- Helmholtz International Lab for Anti-Infectives, Helmholtz Center for Infection Research, 38124, Braunschweig, Germany
| | - Rolf Müller
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), and Department of Pharmacy, Saarland University, 66123, Saarbrücken, Germany
- Helmholtz International Lab for Anti-Infectives, Helmholtz Center for Infection Research, 38124, Braunschweig, Germany
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3
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Wang Y, Yang X, Zhang S, Ai J, Wang J, Chen J, Zhao L, Wang W, You H. Comparative proteomics unveils the bacteriostatic mechanisms of Ga(III) on the regulation of metabolic pathways in Pseudomonas aeruginosa. J Proteomics 2023; 289:105011. [PMID: 37776994 DOI: 10.1016/j.jprot.2023.105011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 09/19/2023] [Accepted: 09/20/2023] [Indexed: 10/02/2023]
Abstract
Gallium has a long history as a chemotherapeutic agent. The mechanisms of action of Ga(III)-based anti-infectives are different from conventional antibiotics, which primarily result from the chemical similarities of Ga(III) with Fe(III) and substitution of gallium into iron-dependent biological pathways. However, more aspects of the molecular mechanisms of Ga(III) against human pathogens, especially the effects on bacterial metabolic processes, remain to be understood. Herein, by using conventional quantitative proteomics, we identified the protein changes of Pseudomonas aeruginosa (P. aeruginosa) in response to Ga(NO3)3 treatment. We show that Ga(III) exhibits bacteriostatic mode of action against P. aeruginosa through affecting the expressions of a number of key enzymes in the main metabolic pathways, including glycolysis, TCA cycle, amino acid metabolism, and protein and nucleic acid biosynthesis. In addition, decreased expressions of proteins associated with pathogenesis and virulence of P. aeruginosa were also identified. Moreover, the correlations between protein expressions and metabolome changes in P. aeruginosa upon Ga(III) treatment were identified and discussed. Our findings thus expand the understanding on the antimicrobial mechanisms of Ga(III) that shed light on enhanced therapeutic strategies. BIOLOGICAL SIGNIFICANCE: Mounting evidence suggest that the efficacy and resistance of clinical antibiotics are closely related to the metabolic homeostasis in bacterial pathogens. Ga(III)-based compounds have been repurposed as antibacterial therapeutic candidates against antibiotics resistant pathogens, and represent a safe and promising treatment for clinical human infections, while more thorough understandings of how bacteria respond to Ga(III) treatment are needed. In the present study, we provide evidences at the proteome level that indicate Ga(III)-induced metabolic perturbations in P. aeruginosa. We identified and discussed the interference of Ga(III) on the expressions and activities of enzymes in the main metabolic pathways in P. aeruginosa. In view of our previous report that the antimicrobial efficacy of Ga(III) could be modulated according to Ga(III)-induced metabolome changes in P. aeruginosa, our current analyses may provide theoretical basis at the proteome level for the development of efficient gallium-based therapies by exploiting bacterial metabolic mechanisms.
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Affiliation(s)
- Yuchuan Wang
- Hebei Key Laboratory for Chronic Diseases, School of Basic Medical Sciences, China.
| | - Xue Yang
- Hebei Key Laboratory for Chronic Diseases, School of Basic Medical Sciences, China
| | - Shuo Zhang
- Hebei Key Laboratory for Chronic Diseases, School of Basic Medical Sciences, China
| | - Jiayi Ai
- Hebei Key Laboratory for Chronic Diseases, School of Basic Medical Sciences, China
| | - Junteng Wang
- School of Public Health, North China University of Science and Technology, Tangshan, Hebei 063210, China
| | - Junxin Chen
- Hebei Key Laboratory for Chronic Diseases, School of Basic Medical Sciences, China
| | - Lin Zhao
- Hebei Key Laboratory for Chronic Diseases, School of Basic Medical Sciences, China
| | - Wanying Wang
- Hebei Key Laboratory for Chronic Diseases, School of Basic Medical Sciences, China
| | - Haoxin You
- Hebei Key Laboratory for Chronic Diseases, School of Basic Medical Sciences, China
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4
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Cornelis P, Tahrioui A, Lesouhaitier O, Bouffartigues E, Feuilloley M, Baysse C, Chevalier S. High affinity iron uptake by pyoverdine in Pseudomonas aeruginosa involves multiple regulators besides Fur, PvdS, and FpvI. Biometals 2023; 36:255-261. [PMID: 35171432 DOI: 10.1007/s10534-022-00369-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 02/03/2022] [Indexed: 11/02/2022]
Abstract
Pseudomonas aeruginosa is a Gram-negative bacterium which can cause serious infections among immune-depressed people including cystic fibrosis patients where it can colonize the lungs causing chronic infections. Iron is essential for P. aeruginosa and can be provided via three sources under aerobic conditions: its own siderophores pyochelin (PCH) and pyoverdine (PVD), xenosiderophores, or heme, respectively. Pyoverdine is the high affinity siderophore and its synthesis and uptake involve more than 30 genes organized in different operons. Its synthesis and uptake are triggered by iron scarcity via the Fur regulator and involves two extra cytoplasmic sigma factors (ECF), PvdS for the biosynthesis of PVD and FpvI for the uptake via the TonB-dependent FpvA outer membrane transporter and other periplasmic and inner membrane proteins. It appeared recently that the regulation of PVD biosynthesis and uptake involves other regulators, including other ECF factors, and LysR regulators. This is the case especially for the genes coding for periplasmic and inner membrane proteins involved in the reduction of Fe3+ to Fe2+ and the transport of ferrous iron to the cytoplasm that appears to represent a crucial step in the uptake process.
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Affiliation(s)
- Pierre Cornelis
- Laboratory of Microbiology Signals and Microenvironnements (LMSM) EA 4312, University of Rouen Normandy, 27000, Evreux, France.
- Laboratorium Microbiologie, Vrije Universiteit Brussel, Brussels, Belgium.
| | - Ali Tahrioui
- Laboratory of Microbiology Signals and Microenvironnements (LMSM) EA 4312, University of Rouen Normandy, 27000, Evreux, France
| | - Olivier Lesouhaitier
- Laboratory of Microbiology Signals and Microenvironnements (LMSM) EA 4312, University of Rouen Normandy, 27000, Evreux, France
| | - Emeline Bouffartigues
- Laboratory of Microbiology Signals and Microenvironnements (LMSM) EA 4312, University of Rouen Normandy, 27000, Evreux, France
| | - Marc Feuilloley
- Laboratory of Microbiology Signals and Microenvironnements (LMSM) EA 4312, University of Rouen Normandy, 27000, Evreux, France
| | - Christine Baysse
- CNRS, Institut de Génétique et de Développement de Rennes (IGDR), UMR6290, Université de Rennes, Rennes, France
| | - Sylvie Chevalier
- Laboratory of Microbiology Signals and Microenvironnements (LMSM) EA 4312, University of Rouen Normandy, 27000, Evreux, France
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5
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Li Z, He L, Wang X, Huo Q, Zheng G, Kong D, Lu Y, Xia H, Niu G. Elucidation of the ferrichrome siderophore biosynthetic pathway in albomycin-producing Streptomyces sp. ATCC 700974. J Biol Chem 2023; 299:104573. [PMID: 36870685 PMCID: PMC10124919 DOI: 10.1016/j.jbc.2023.104573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 02/23/2023] [Accepted: 02/24/2023] [Indexed: 03/06/2023] Open
Abstract
Sideromycins are a unique subset of siderophores comprising of a siderophore conjugated to an antimicrobial agent. The "Trojan horse" antibiotic albomycins are unique sideromycins consisting of a ferrichrome-type siderophore conjugated to a peptidyl nucleoside antibiotic. They exhibit potent antibacterial activities against many model bacteria and a number of clinical pathogens. Earlier studies have provided significant insight into the biosynthetic pathway of the peptidyl nucleoside moiety. We herein decipher the biosynthetic pathway of the ferrichrome-type siderophore in Streptomyces sp. ATCC 700974. Our genetic studies suggested that abmA, abmB, and abmQ are involved in the formation of the ferrichrome-type siderophore. Additionally, we performed biochemical studies to demonstrate that a flavin-dependent monooxygenase AbmB and an N-acyltransferase AbmA catalyze sequential modifications of L-ornithine to generate N5-acetyl-N5-hydroxyornithine. Three molecules of N5-acetyl-N5-hydroxyornithine are then assembled to generate the tripeptide ferrichrome through the action of a non-ribosomal peptide synthetase AbmQ. Of special note, we found out that orf05026 and orf03299, two genes scattered elsewhere in the chromosome of Streptomyces sp. ATCC 700974, have functional redundancy for abmA and abmB, respectively. Interestingly, both orf05026 and orf03299 are situated within gene clusters encoding putative siderophores. In summary, this study provided new insight into the siderophore moiety of albomycin biosynthesis, and shed light on the contingency of multiple siderophores in albomycin-producing Streptomyces sp. ATCC 700974.
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Affiliation(s)
- Zhilei Li
- Biotechnology Research Center, Southwest University, Chongqing, 400715, China
| | - Lang He
- Biotechnology Research Center, Southwest University, Chongqing, 400715, China
| | - Xia Wang
- Biotechnology Research Center, Southwest University, Chongqing, 400715, China
| | - Qingwen Huo
- Biotechnology Research Center, Southwest University, Chongqing, 400715, China
| | - Guosong Zheng
- College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Dekun Kong
- Biotechnology Research Center, Southwest University, Chongqing, 400715, China
| | - Yinhua Lu
- College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Haiyang Xia
- Institute of Biopharmaceuticals, Taizhou University, Taizhou, 318000, China
| | - Guoqing Niu
- Biotechnology Research Center, Southwest University, Chongqing, 400715, China.
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6
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Butler A, Jelowicki AM, Ogasawara HA, Reitz ZL, Stow PR, Thomsen E. Mining elements of siderophore chirality encoded in microbial genomes. FEBS Lett 2023; 597:134-140. [PMID: 36370136 DOI: 10.1002/1873-3468.14539] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 11/04/2022] [Accepted: 11/07/2022] [Indexed: 11/13/2022]
Abstract
The vast majority of bacteria require iron to grow. A significant iron acquisition strategy is the production of siderophores, which are secondary microbial metabolites synthesized to sequester iron(III). Siderophore structures encompass a variety of forms, of which highly modified peptidic siderophores are of interest herein. State-of-the-art genome mining tools, such as antiSMASH (antibiotics & Secondary Metabolite Analysis SHell), hold the potential to predict and discover new peptidic siderophores, including a combinatoric suite of triscatechol siderophores framed on a triserine-ester backbone of the general class, (DHB-l/d CAA-l Ser)3 (CAA, cationic amino acid). Siderophores with l/d Arg, l/d Lys and l Orn, but not d Orn, were predicted in bacterial genomes. Fortuitously the d Orn siderophore was identified, yet its lack of prediction highlights the limitation of current genome mining tools. The full combinatoric suite of these siderophores, which form chiral iron(III) complexes, reveals stereospecific coordination chemistry encoded in microbial genomes. The chirality embedded in this suite of Fe(III)-siderophores raises the question of whether the relevant siderophore-mediated iron acquisition pathways are stereospecific and selective for ferric siderophore complexes of a defined configuration.
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Affiliation(s)
- Alison Butler
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, USA
| | - Aneta M Jelowicki
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, USA
| | - Haley A Ogasawara
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, USA
| | - Zachary L Reitz
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, USA
| | - Parker R Stow
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, USA
| | - Emil Thomsen
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, USA
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7
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Ernst S, Mährlein A, Ritzmann NH, Drees SL, Fetzner S. A comparative study of
N
‐hydroxylating flavoprotein monooxygenases reveals differences in kinetics and cofactor binding. FEBS J 2022; 289:5637-5655. [DOI: 10.1111/febs.16444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 02/21/2022] [Accepted: 03/18/2022] [Indexed: 12/01/2022]
Affiliation(s)
- Simon Ernst
- Institute of Molecular Microbiology and Biotechnology University of Münster Germany
| | - Almuth Mährlein
- Institute of Molecular Microbiology and Biotechnology University of Münster Germany
| | - Niklas H. Ritzmann
- Institute of Molecular Microbiology and Biotechnology University of Münster Germany
| | - Steffen L. Drees
- Institute of Molecular Microbiology and Biotechnology University of Münster Germany
| | - Susanne Fetzner
- Institute of Molecular Microbiology and Biotechnology University of Münster Germany
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8
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He HY, Niikura H, Du YL, Ryan KS. Synthetic and biosynthetic routes to nitrogen-nitrogen bonds. Chem Soc Rev 2022; 51:2991-3046. [PMID: 35311838 DOI: 10.1039/c7cs00458c] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The nitrogen-nitrogen bond is a core feature of diverse functional groups like hydrazines, nitrosamines, diazos, and pyrazoles. Such functional groups are found in >300 known natural products. Such N-N bond-containing functional groups are also found in significant percentage of clinical drugs. Therefore, there is wide interest in synthetic and enzymatic methods to form nitrogen-nitrogen bonds. In this review, we summarize synthetic and biosynthetic approaches to diverse nitrogen-nitrogen-bond-containing functional groups, with a focus on biosynthetic pathways and enzymes.
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Affiliation(s)
- Hai-Yan He
- Department of Chemistry, University of British Columbia, Vancouver, Canada. .,Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
| | - Haruka Niikura
- Department of Chemistry, University of British Columbia, Vancouver, Canada.
| | - Yi-Ling Du
- Institute of Pharmaceutical Biotechnology, Zhejiang University School of Medicine, Hangzhou, China
| | - Katherine S Ryan
- Department of Chemistry, University of British Columbia, Vancouver, Canada.
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9
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Haupka C, Brito LF, Busche T, Wibberg D, Wendisch VF. Genomic and Transcriptomic Investigation of the Physiological Response of the Methylotroph Bacillus methanolicus to 5-Aminovalerate. Front Microbiol 2021; 12:664598. [PMID: 33995329 PMCID: PMC8119775 DOI: 10.3389/fmicb.2021.664598] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 03/22/2021] [Indexed: 11/19/2022] Open
Abstract
The methylotrophic thermophile Bacillus methanolicus can utilize the non-food substrate methanol as its sole carbon and energy source. Metabolism of L-lysine, in particular its biosynthesis, has been studied to some detail, and methanol-based L-lysine production has been achieved. However, little is known about L-lysine degradation, which may proceed via 5-aminovalerate (5AVA), a non-proteinogenic ω-amino acid with applications in bioplastics. The physiological role of 5AVA and related compounds in the native methylotroph was unknown. Here, we showed that B. methanolicus exhibits low tolerance to 5AVA, but not to related short-chain (C4–C6) amino acids, diamines, and dicarboxylic acids. In order to gain insight into the physiological response of B. methanolicus to 5AVA, transcriptomic analyses by differential RNA-Seq in the presence and absence of 5AVA were performed. Besides genes of the general stress response, RNA levels of genes of histidine biosynthesis, and iron acquisition were increased in the presence of 5AVA, while an Rrf2 family transcriptional regulator gene showed reduced RNA levels. In order to test if mutations can overcome growth inhibition by 5AVA, adaptive laboratory evolution (ALE) was performed and two mutants—AVA6 and AVA10—with higher tolerance to 5AVA were selected. Genome sequencing revealed mutations in genes related to iron homeostasis, including the gene for an iron siderophore-binding protein. Overexpression of this mutant gene in the wild-type (WT) strain MGA3 improved 5AVA tolerance significantly at high Fe2+ supplementation. The combined ALE, omics, and genetics approach helped elucidate the physiological response of thermophilic B. methanolicus to 5AVA and will guide future strain development for 5AVA production from methanol.
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Affiliation(s)
- Carsten Haupka
- Genetics of Prokaryotes, Faculty of Biology, CeBiTec, Bielefeld University, Bielefeld, Germany
| | - Luciana F Brito
- Department of Biotechnology and Food Science, Norwegian University of Science and Technology, Trondheim, Norway
| | - Tobias Busche
- Technology Platform Genomics, Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Daniel Wibberg
- Genome Research of Industrial Microorganisms, Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Volker F Wendisch
- Genetics of Prokaryotes, Faculty of Biology, CeBiTec, Bielefeld University, Bielefeld, Germany
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10
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Giddings LA, Lountos GT, Kim KW, Brockley M, Needle D, Cherry S, Tropea JE, Waugh DS. Characterization of a broadly specific cadaverine N-hydroxylase involved in desferrioxamine B biosynthesis in Streptomyces sviceus. PLoS One 2021; 16:e0248385. [PMID: 33784308 PMCID: PMC8009421 DOI: 10.1371/journal.pone.0248385] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 02/26/2021] [Indexed: 02/07/2023] Open
Abstract
N-hydroxylating flavin-dependent monooxygenases (FMOs) are involved in the biosynthesis of hydroxamate siderophores, playing a key role in microbial virulence. Herein, we report the first structural and kinetic characterization of a novel alkyl diamine N-hydroxylase DesB from Streptomyces sviceus (SsDesB). This enzyme catalyzes the first committed step in the biosynthesis of desferrioxamine B, a clinical drug used to treat iron overload disorders. X-ray crystal structures of the SsDesB holoenzyme with FAD and the ternary complex with bound NADP+ were solved at 2.86 Å and 2.37 Å resolution, respectively, providing a structural view of the active site environment. SsDesB crystallized as a tetramer and the structure of the individual protomers closely resembles the structures of homologous N-hydroxylating FMOs from Erwinia amylovora (DfoA), Pseudomonas aeruginosa (PvdA), and Aspergillus fumigatus (SidA). Using NADPH oxidation, oxygen consumption, and product formation assays, kinetic parameters were determined for various substrates with SsDesB. SsDesB exhibited typical saturation kinetics with substrate inhibition at high concentrations of NAD(P)H as well as cadaverine. The apparent kcat values for NADPH in steady-state NADPH oxidation and oxygen consumption assays were 0.28 ± 0.01 s-1 and 0.24 ± 0.01 s-1, respectively. However, in product formation assays used to measure the rate of N-hydroxylation, the apparent kcat for NADPH (0.034 ± 0.008 s-1) was almost 10-fold lower under saturating FAD and cadaverine concentrations, reflecting an uncoupled reaction, and the apparent NADPH KM was 33 ± 24 μM. Under saturating FAD and NADPH concentrations, the apparent kcat and KM for cadaverine in Csaky assays were 0.048 ± 0.004 s-1 and 19 ± 9 μM, respectively. SsDesB also N-hydroxylated putrescine, spermidine, and L-lysine substrates but not alkyl (di)amines that were branched or had fewer than four methylene units in an alkyl chain. These data demonstrate that SsDesB has wider substrate scope compared to other well-studied ornithine and lysine N-hydroxylases, making it an amenable biocatalyst for the production of desferrioxamine B, derivatives, and other N-substituted products.
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Affiliation(s)
- Lesley-Ann Giddings
- Department of Chemistry, Smith College, Northampton, MA, United States of America
- Department of Chemistry & Biochemistry, Middlebury College, Middlebury, VT, United States of America
| | - George T. Lountos
- Basic Science Program, Frederick National Laboratory for Cancer Research, Frederick, MD, United States of America
| | - Kang Woo Kim
- Department of Chemistry & Biochemistry, Middlebury College, Middlebury, VT, United States of America
| | - Matthew Brockley
- Department of Chemistry & Biochemistry, Middlebury College, Middlebury, VT, United States of America
| | - Danielle Needle
- Center for Structural Biology, Center for Cancer Research, National Cancer Institute, Frederick, MD, United States of America
| | - Scott Cherry
- Center for Structural Biology, Center for Cancer Research, National Cancer Institute, Frederick, MD, United States of America
| | - Joseph E. Tropea
- Center for Structural Biology, Center for Cancer Research, National Cancer Institute, Frederick, MD, United States of America
| | - David S. Waugh
- Center for Structural Biology, Center for Cancer Research, National Cancer Institute, Frederick, MD, United States of America
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11
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Identification of Active Site Residues of the Siderophore Synthesis Enzyme PvdF and Evidence for Interaction of PvdF with a Substrate-Providing Enzyme. Int J Mol Sci 2021; 22:ijms22042211. [PMID: 33672312 PMCID: PMC7926923 DOI: 10.3390/ijms22042211] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 02/03/2021] [Accepted: 02/08/2021] [Indexed: 11/17/2022] Open
Abstract
The problematic opportunistic pathogen Pseudomonas aeruginosa secretes a siderophore, pyoverdine. Pyoverdine scavenges iron needed by the bacteria for growth and for pathogenicity in a range of different infection models. PvdF, a hydroxyornithine transformylase enzyme, is essential for pyoverdine synthesis, catalysing synthesis of formylhydroxyornithine (fOHOrn) that forms part of the pyoverdine molecule and provides iron-chelating hydroxamate ligands. Using a mass spectrometry assay, we confirm that purified PvdF catalyses synthesis of fOHOrn from hydroxyornithine and formyltetrahydrofolate substrates. Site directed mutagenesis was carried out to investigate amino acid residues predicted to be required for enzymatic activity. Enzyme variants were assayed for activity in vitro and also in vivo, through measuring their ability to restore pyoverdine production to a pvdF mutant strain. Variants at two putative catalytic residues N168 and H170 greatly reduced enzymatic activity in vivo though did not abolish activity in vitro. Change of a third residue D229 abolished activity both in vivo and in vitro. A change predicted to block entry of N10-formyltetrahydrofolate (fTHF) to the active site also abolished activity both in vitro and in vivo. A co-purification assay showed that PvdF binds to an enzyme PvdA that catalyses synthesis of hydroxyornithine, with this interaction likely to increase the efficiency of fOHOrn synthesis. Our findings advance understanding of how P. aeruginosa synthesises pyoverdine, a key factor in host-pathogen interactions.
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12
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Mügge C, Heine T, Baraibar AG, van Berkel WJH, Paul CE, Tischler D. Flavin-dependent N-hydroxylating enzymes: distribution and application. Appl Microbiol Biotechnol 2020; 104:6481-6499. [PMID: 32504128 PMCID: PMC7347517 DOI: 10.1007/s00253-020-10705-w] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 05/18/2020] [Accepted: 05/24/2020] [Indexed: 02/06/2023]
Abstract
Amino groups derived from naturally abundant amino acids or (di)amines can be used as "shuttles" in nature for oxygen transfer to provide intermediates or products comprising N-O functional groups such as N-hydroxy, oxazine, isoxazolidine, nitro, nitrone, oxime, C-, S-, or N-nitroso, and azoxy units. To this end, molecular oxygen is activated by flavin, heme, or metal cofactor-containing enzymes and transferred to initially obtain N-hydroxy compounds, which can be further functionalized. In this review, we focus on flavin-dependent N-hydroxylating enzymes, which play a major role in the production of secondary metabolites, such as siderophores or antimicrobial agents. Flavoprotein monooxygenases of higher organisms (among others, in humans) can interact with nitrogen-bearing secondary metabolites or are relevant with respect to detoxification metabolism and are thus of importance to understand potential medical applications. Many enzymes that catalyze N-hydroxylation reactions have specific substrate scopes and others are rather relaxed. The subsequent conversion towards various N-O or N-N comprising molecules is also described. Overall, flavin-dependent N-hydroxylating enzymes can accept amines, diamines, amino acids, amino sugars, and amino aromatic compounds and thus provide access to versatile families of compounds containing the N-O motif. Natural roles as well as synthetic applications are highlighted. Key points • N-O and N-N comprising natural and (semi)synthetic products are highlighted. • Flavin-based NMOs with respect to mechanism, structure, and phylogeny are reviewed. • Applications in natural product formation and synthetic approaches are provided. Graphical abstract .
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Affiliation(s)
- Carolin Mügge
- Microbial Biotechnology, Faculty of Biology and Biotechnology, Ruhr-Universität Bochum, Universitätsstr. 150, 44780, Bochum, Germany
| | - Thomas Heine
- Environmental Microbiology, Faculty of Chemistry and Physics, TU Bergakademie Freiberg, Leipziger Str. 29, 09599, Freiberg, Germany
| | - Alvaro Gomez Baraibar
- Microbial Biotechnology, Faculty of Biology and Biotechnology, Ruhr-Universität Bochum, Universitätsstr. 150, 44780, Bochum, Germany
- Rottendorf Pharma GmbH, Ostenfelder Str. 51-61, 59320, Ennigerloh, Germany
| | - Willem J H van Berkel
- Laboratory of Food Chemistry, Wageningen University & Research, Bornse Weilanden 9, 6708 WG, Wageningen, The Netherlands
| | - Caroline E Paul
- Biocatalysis, Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, HZ 2629, Delft, The Netherlands
| | - Dirk Tischler
- Microbial Biotechnology, Faculty of Biology and Biotechnology, Ruhr-Universität Bochum, Universitätsstr. 150, 44780, Bochum, Germany.
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13
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Panayidou S, Georgiades K, Christofi T, Tamana S, Promponas VJ, Apidianakis Y. Pseudomonas aeruginosa core metabolism exerts a widespread growth-independent control on virulence. Sci Rep 2020; 10:9505. [PMID: 32528034 PMCID: PMC7289854 DOI: 10.1038/s41598-020-66194-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 05/13/2020] [Indexed: 02/04/2023] Open
Abstract
To assess the role of core metabolism genes in bacterial virulence - independently of their effect on growth - we correlated the genome, the transcriptome and the pathogenicity in flies and mice of 30 fully sequenced Pseudomonas strains. Gene presence correlates robustly with pathogenicity differences among all Pseudomonas species, but not among the P. aeruginosa strains. However, gene expression differences are evident between highly and lowly pathogenic P. aeruginosa strains in multiple virulence factors and a few metabolism genes. Moreover, 16.5%, a noticeable fraction of the core metabolism genes of P. aeruginosa strain PA14 (compared to 8.5% of the non-metabolic genes tested), appear necessary for full virulence when mutated. Most of these virulence-defective core metabolism mutants are compromised in at least one key virulence mechanism independently of auxotrophy. A pathway level analysis of PA14 core metabolism, uncovers beta-oxidation and the biosynthesis of amino-acids, succinate, citramalate, and chorismate to be important for full virulence. Strikingly, the relative expression among P. aeruginosa strains of genes belonging in these metabolic pathways is indicative of their pathogenicity. Thus, P. aeruginosa strain-to-strain virulence variation, remains largely obscure at the genome level, but can be dissected at the pathway level via functional transcriptomics of core metabolism.
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Affiliation(s)
- Stavria Panayidou
- Infection and Cancer Laboratory, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
| | - Kaliopi Georgiades
- Infection and Cancer Laboratory, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus.,Bioinformatics Research Laboratory, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
| | - Theodoulakis Christofi
- Infection and Cancer Laboratory, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
| | - Stella Tamana
- Bioinformatics Research Laboratory, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
| | - Vasilis J Promponas
- Bioinformatics Research Laboratory, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus.
| | - Yiorgos Apidianakis
- Infection and Cancer Laboratory, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus.
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14
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Schalk IJ, Rigouin C, Godet J. An overview of siderophore biosynthesis among fluorescent Pseudomonads and new insights into their complex cellular organization. Environ Microbiol 2020; 22:1447-1466. [PMID: 32011068 DOI: 10.1111/1462-2920.14937] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 01/25/2020] [Accepted: 01/28/2020] [Indexed: 01/02/2023]
Abstract
Siderophores are iron-chelating molecules produced by bacteria to access iron, a key nutrient. These compounds have highly diverse chemical structures, with various chelating groups. They are released by bacteria into their environment to scavenge iron and bring it back into the cells. The biosynthesis of siderophores requires complex enzymatic processes and expression of the enzymes involved is very finely regulated by iron availability and diverse transcriptional regulators. Recent data have also highlighted the organization of the enzymes involved in siderophore biosynthesis into siderosomes, multi-enzymatic complexes involved in siderophore synthesis. An understanding of siderophore biosynthesis is of great importance, as these compounds have many potential biotechnological applications because of their metal-chelating properties and their key role in bacterial growth and virulence. This review focuses on the biosynthesis of siderophores produced by fluorescent Pseudomonads, bacteria capable of colonizing a large variety of ecological niches. They are characterized by the production of chromopeptide siderophores, called pyoverdines, which give the typical green colour characteristic of fluorescent pseudomonad cultures. Secondary siderophores are also produced by these strains and can have highly diverse structures (such as pyochelins, pseudomonine, yersiniabactin, corrugatin, achromobactin and quinolobactin).
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Affiliation(s)
- Isabelle J Schalk
- CNRS, UMR7242, ESBS, Illkirch, Strasbourg, France.,Université de Strasbourg, UMR7242, ESBS, Illkirch, Strasbourg, France
| | - Coraline Rigouin
- CNRS, UMR7242, ESBS, Illkirch, Strasbourg, France.,Université de Strasbourg, UMR7242, ESBS, Illkirch, Strasbourg, France
| | - Julien Godet
- Université de Strasbourg, Laboratoire de BioImagerie et Pathologies, UMR CNRS, 7021, Illkirch, France
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15
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Li J, Zhang Y, Li J, Sun T, Tian C. Metabolic engineering of the cellulolytic thermophilic fungus Myceliophthora thermophila to produce ethanol from cellobiose. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:23. [PMID: 32021654 PMCID: PMC6995234 DOI: 10.1186/s13068-020-1661-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 01/21/2020] [Indexed: 05/28/2023]
Abstract
BACKGROUND Cellulosic biomass is a promising resource for bioethanol production. However, various sugars in plant biomass hydrolysates including cellodextrins, cellobiose, glucose, xylose, and arabinose, are poorly fermented by microbes. The commonly used ethanol-producing microbe Saccharomyces cerevisiae can usually only utilize glucose, although metabolically engineered strains that utilize xylose have been developed. Direct fermentation of cellobiose could avoid glucose repression during biomass fermentation, but applications of an engineered cellobiose-utilizing S. cerevisiae are still limited because of its long lag phase. Bioethanol production from biomass-derived sugars by a cellulolytic filamentous fungus would have many advantages for the biorefinery industry. RESULTS We selected Myceliophthora thermophila, a cellulolytic thermophilic filamentous fungus for metabolic engineering to produce ethanol from glucose and cellobiose. Ethanol production was increased by 57% from glucose but not cellobiose after introduction of ScADH1 into the wild-type (WT) strain. Further overexpression of a glucose transporter GLT-1 or the cellodextrin transport system (CDT-1/CDT-2) from N. crassa increased ethanol production by 131% from glucose or by 200% from cellobiose, respectively. Transcriptomic analysis of the engineered cellobiose-utilizing strain and WT when grown on cellobiose showed that genes involved in oxidation-reduction reactions and the stress response were downregulated, whereas those involved in protein biosynthesis were upregulated in this effective ethanol production strain. Turning down the expression of pyc gene results the final engineered strain with the ethanol production was further increased by 23%, reaching up to 11.3 g/L on cellobiose. CONCLUSIONS This is the first attempt to engineer the cellulolytic fungus M. thermophila to produce bioethanol from biomass-derived sugars such as glucose and cellobiose. The ethanol production can be improved about 4 times up to 11 grams per liter on cellobiose after a couple of genetic engineering. These results show that M. thermophila is a promising platform for bioethanol production from cellulosic materials in the future.
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Affiliation(s)
- Jinyang Li
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Yongli Zhang
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Jingen Li
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
| | - Tao Sun
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
| | - Chaoguang Tian
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
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16
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In cellulo FRET-FLIM and single molecule tracking reveal the supra-molecular organization of the pyoverdine bio-synthetic enzymes in Pseudomonas aeruginosa. Q Rev Biophys 2020; 53:e1. [PMID: 31915092 DOI: 10.1017/s0033583519000155] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The bio-synthesis of pyoverdine (PVD) in Pseudomonas aeruginosa involves multiple enzymatic steps including the action of non-ribosomal peptide synthetases (NRPSs). One hallmark of NRPS is their ability to make usage of non-proteinogenic amino-acids synthesized by co-expressed accessory enzymes. It is generally proposed that different enzymes of a secondary metabolic pathway assemble into large supra-molecular complexes. However, evidence for the assembly of sequential enzymes in the cellular context is sparse. Here, we used in cellulo single-molecule tracking and Förster resonance energy transfer measured by fluorescence lifetime microscopy (FRET-FLIM) to explore the spatial partitioning of the ornithine hydroxylase PvdA and its interactions with NRPS. We found PvdA was mostly diffusing bound to large complexes in the cytoplasm with a small exchangeable trapped fraction. FRET-FLIM clearly showed that PvdA is physically interacting with PvdJ, PvdI, PvdL, and PvdD, the four NRPS involved in the PVD pathway in Pseudomonas aeruginosa PAO1. The binding modes of PvdA were strikingly different according to the NRPS it is interacting with, suggesting that PvdA binding sites have co-evolved with the enzymatic active sites of NRPS. Our data provide evidence for strongly organized multi-enzymatic complexes responsible for the bio-synthesis of PVD and illustrate how binding sites have evolved to finely control the co-localization of sequential enzymes and promote metabolic pathway efficiency.
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17
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Saroja NR, Mohan AHS, Srividya D, Supreetha K. Chaperone-assisted expression and purification of putrescine monooxygenase from Shewanella putrefaciens-95. Protein Expr Purif 2019; 157:9-16. [PMID: 30654014 DOI: 10.1016/j.pep.2019.01.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Revised: 01/09/2019] [Accepted: 01/09/2019] [Indexed: 01/22/2023]
Abstract
A putrescine monooxygenase from Shewanella putrefaciens 95 (SpPMO) is the initial enzyme catalyzing the hydroxylation of putrescine to N-hydroxyl putrescine, the precursor for the synthesis of a siderophore putrebactin was identified. This PMO clustered together with known characterized NMOs from Shewanella baltica, Bordetella pertussis, Erwinia amylovora, Streptomyces sp. Gordonia rubripertincta, Pseudomonas aeruginosa and outgrouped from Escherichia coli, Nocardia farcinica, and Rhodococcus erythropolis. The deduced SpPMO protein showed 53% and 36% sequence identity with other characterized bacterial NMOs from Erwinia amylovora and Gordonia rubripertincta respectively. In this investigation, we have cloned the complete 1518bp coding sequence of pubA from Shewanella putrefaciens 95 encoding the corresponding protein SpPMO. It comprises 505 amino acid residues in length and has approximately a molecular weight of 54 kDa. Chaperone-assisted heterologous expression of SpPMO in pET151Topo expression vector under the control of bacteriophage T7 promoter permitted a stringent IPTG dependent expression. It has been successfully cloned, overexpressed and purified as a soluble His6 -tagged enzyme using E. coli as a cloning and expression host. The expression of recombinant SpPMO was confirmed by Western blotting using anti-His6 antibody. The purified protein showed FAD and NADPH dependent N-hydroxylation activity. This study has paved a way to understand the hydroxylation step of putrebactin synthesis which can be further investigated by studying its kinetic mechanism and physiological role.
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Affiliation(s)
- Narsing Rao Saroja
- Pesticide Residue and Food Quality Analysis Laboratory, University of Agricultural Sciences, Raichur, 584104, Karnataka, India.
| | - Anil H Shyam Mohan
- Department of Biotechnology, Dayananda Sagar College of Engineering, Kumaraswamy Layout, Shavige Malleswara Hills, Bengaluru, 78, Karnataka, India
| | - D Srividya
- Pesticide Residue and Food Quality Analysis Laboratory, University of Agricultural Sciences, Raichur, 584104, Karnataka, India
| | - K Supreetha
- Department of Biotechnology, Dayananda Sagar College of Engineering, Kumaraswamy Layout, Shavige Malleswara Hills, Bengaluru, 78, Karnataka, India
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18
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Ringel MT, Brüser T. The biosynthesis of pyoverdines. MICROBIAL CELL (GRAZ, AUSTRIA) 2018; 5:424-437. [PMID: 30386787 PMCID: PMC6206403 DOI: 10.15698/mic2018.10.649] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 07/03/2018] [Indexed: 01/11/2023]
Abstract
Pyoverdines are fluorescent siderophores of pseudomonads that play important roles for growth under iron-limiting conditions. The production of pyoverdines by fluorescent pseudomonads permits their colonization of hosts ranging from humans to plants. Prominent examples include pathogenic or non-pathogenic species such as Pseudomonas aeruginosa, P. putida, P. syringae, or P. fluorescens. Many distinct pyoverdines have been identified, all of which have a dihydroxyquinoline fluorophore in common, derived from oxidative cyclizations of non-ribosomal peptides. These serve as precursor of pyoverdines and are commonly known as ferribactins. Ferribactins of distinct species or even strains often differ in their sequence, resulting in a large variety of pyoverdines. However, synthesis of all ferribactins begins with an L-Glu/D-Tyr/L-Dab sequence, and the fluorophore is generated from the D-Tyr/L-Dab residues. In addition, the initial L-Glu residue is modified to various acids and amides that are responsible for the range of distinguishable pyoverdines in individual strains. While ferribactin synthesis is a cytoplasmic process, the maturation to the fluorescent pyoverdine as well as the tailoring of the initial glutamate are exclusively periplasmic processes that have been a mystery until recently. Here we review the current knowledge of pyoverdine biosynthesis with a focus on the recent advancements regarding the periplasmic maturation and tailoring reactions.
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Affiliation(s)
- Michael T. Ringel
- Institute of Microbiology, Leibniz University Hannover, Herrenhäuser Str. 2, 30419 Hannover, Germany
| | - Thomas Brüser
- Institute of Microbiology, Leibniz University Hannover, Herrenhäuser Str. 2, 30419 Hannover, Germany
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19
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Matsuda K, Tomita T, Shin-ya K, Wakimoto T, Kuzuyama T, Nishiyama M. Discovery of Unprecedented Hydrazine-Forming Machinery in Bacteria. J Am Chem Soc 2018; 140:9083-9086. [DOI: 10.1021/jacs.8b05354] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Kenichi Matsuda
- Biotechnology Research Center, The University of Tokyo, Tokyo 113-8657, Japan
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan
| | - Takeo Tomita
- Biotechnology Research Center, The University of Tokyo, Tokyo 113-8657, Japan
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo 113-8657, Japan
| | - Kazuo Shin-ya
- Biotechnology Research Center, The University of Tokyo, Tokyo 113-8657, Japan
- National Institute of Advanced Industrial Science and Technology (AIST), Tokyo 135-0064, Japan
| | - Toshiyuki Wakimoto
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan
| | - Tomohisa Kuzuyama
- Biotechnology Research Center, The University of Tokyo, Tokyo 113-8657, Japan
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo 113-8657, Japan
| | - Makoto Nishiyama
- Biotechnology Research Center, The University of Tokyo, Tokyo 113-8657, Japan
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo 113-8657, Japan
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20
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Abstract
Covering: up to 2017.Natural products are important secondary metabolites produced by bacterial and fungal species that play important roles in cellular growth and signaling, nutrient acquisition, intra- and interspecies communication, and virulence. A subset of natural products is produced by nonribosomal peptide synthetases (NRPSs), a family of large, modular enzymes that function in an assembly line fashion. Because of the pharmaceutical activity of many NRPS products, much effort has gone into the exploration of their biosynthetic pathways and the diverse products they make. Many interesting NRPS pathways have been identified and characterized from both terrestrial and marine bacterial sources. Recently, several NRPS pathways in human commensal bacterial species have been identified that produce molecules with antibiotic activity, suggesting another source of interesting NRPS pathways may be the commensal and pathogenic bacteria that live on the human body. The ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) have been identified as a significant cause of human bacterial infections that are frequently multidrug resistant. The emerging resistance profile of these organisms has prompted calls from multiple international agencies to identify novel antibacterial targets and develop new approaches to treat infections from ESKAPE pathogens. Each of these species contains several NRPS biosynthetic gene clusters. While some have been well characterized and produce known natural products with important biological roles in microbial physiology, others have yet to be investigated. This review catalogs the NRPS pathways of ESKAPE pathogens. The exploration of novel NRPS products may lead to a better understanding of the chemical communication used by human pathogens and potentially to the discovery of novel therapeutic approaches.
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Affiliation(s)
- Andrew M Gulick
- Hauptman-Woodward Medical Research Institute, 700 Ellicott Street, Buffalo, NY 14203, USA.
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21
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Waldman AJ, Ng TL, Wang P, Balskus EP. Heteroatom-Heteroatom Bond Formation in Natural Product Biosynthesis. Chem Rev 2017; 117:5784-5863. [PMID: 28375000 PMCID: PMC5534343 DOI: 10.1021/acs.chemrev.6b00621] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Natural products that contain functional groups with heteroatom-heteroatom linkages (X-X, where X = N, O, S, and P) are a small yet intriguing group of metabolites. The reactivity and diversity of these structural motifs has captured the interest of synthetic and biological chemists alike. Functional groups containing X-X bonds are found in all major classes of natural products and often impart significant biological activity. This review presents our current understanding of the biosynthetic logic and enzymatic chemistry involved in the construction of X-X bond containing functional groups within natural products. Elucidating and characterizing biosynthetic pathways that generate X-X bonds could both provide tools for biocatalysis and synthetic biology, as well as guide efforts to uncover new natural products containing these structural features.
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Affiliation(s)
- Abraham J. Waldman
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, United States
| | - Tai L. Ng
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, United States
| | - Peng Wang
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, United States
| | - Emily P. Balskus
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, United States
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22
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Identification and characterization of a FAD-dependent putrescine N-hydroxylase (GorA) from Gordonia rubripertincta CWB2. ACTA ACUST UNITED AC 2016. [DOI: 10.1016/j.molcatb.2016.08.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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23
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Abdelwahab H, Robinson R, Rodriguez P, Adly C, El-Sohaimy S, Sobrado P. Identification of structural determinants of NAD(P)H selectivity and lysine binding in lysine N(6)-monooxygenase. Arch Biochem Biophys 2016; 606:180-8. [PMID: 27503802 DOI: 10.1016/j.abb.2016.08.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 07/22/2016] [Accepted: 08/01/2016] [Indexed: 11/26/2022]
Abstract
l-lysine (l-Lys) N(6)-monooxygenase (NbtG), from Nocardia farcinica, is a flavin-dependent enzyme that catalyzes the hydroxylation of l-Lys in the presence of oxygen and NAD(P)H in the biosynthetic pathway of the siderophore nocobactin. NbtG displays only a 3-fold preference for NADPH over NADH, different from well-characterized related enzymes, which are highly selective for NADPH. The structure of NbtG with bound NAD(P)(+) or l-Lys is currently not available. Herein, we present a mutagenesis study targeting M239, R301, and E216. These amino acids are conserved and located in either the NAD(P)H binding domain or the l-Lys binding pocket. M239R resulted in high production of hydrogen peroxide and little hydroxylation with no change in coenzyme selectivity. R301A caused a 300-fold decrease on kcat/Km value with NADPH but no change with NADH. E216Q increased the Km value for l-Lys by 30-fold with very little change on the kcat value or in the binding of NAD(P)H. These results suggest that R301 plays a major role in NADPH selectivity by interacting with the 2'-phosphate of the adenine-ribose moiety of NADPH, while E216 plays a role in l-Lys binding.
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Affiliation(s)
- Heba Abdelwahab
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061, USA; Department of Chemistry, Faculty of Science, Damietta University, Damietta, 34517, Egypt
| | - Reeder Robinson
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061, USA
| | - Pedro Rodriguez
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061, USA
| | - Camelia Adly
- Department of Chemistry, Faculty of Science, Damietta University, Damietta, 34517, Egypt
| | - Sohby El-Sohaimy
- Department of Food Technology, Arid Lands Cultivation Research Institute, City of Scientific Research and Technological Applications, Alexandria, 21934, Egypt
| | - Pablo Sobrado
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061, USA; Fralin Life Science Institute, Virginia Tech, Blacksburg, VA 24061, USA; Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, VA 24061, USA.
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24
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Zhao S, Wei H, Lin CY, Zeng Y, Tucker MP, Himmel ME, Ding SY. Burkholderia phytofirmans Inoculation-Induced Changes on the Shoot Cell Anatomy and Iron Accumulation Reveal Novel Components of Arabidopsis-Endophyte Interaction that Can Benefit Downstream Biomass Deconstruction. FRONTIERS IN PLANT SCIENCE 2016; 7:24. [PMID: 26858740 PMCID: PMC4731519 DOI: 10.3389/fpls.2016.00024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/28/2015] [Accepted: 01/08/2016] [Indexed: 06/05/2023]
Abstract
It is known that plant growth promoting bacteria (PGPB) elicit positive effects on plant growth and biomass yield. However, the actual mechanism behind the plant-PGPB interaction is poorly understood, and the literature is scarce regarding the thermochemical pretreatability and enzymatic degradability of biomass derived from PGPB-inoculated plants. Most recent transcriptional analyses of PGPB strain Burkholderia phytofirmans PsJN inoculating potato in literature and Arabidopsis in our present study have revealed the expression of genes for ferritin and the biosynthesis and transport of siderophores (i.e., the molecules with high affinity for iron), respectively. The expression of such genes in the shoots of PsJN-inoculated plants prompted us to propose that PsJN-inoculation can improve the host plant's iron uptake and accumulation, which facilitates the downstream plant biomass pretreatment and conversion to simple sugars. In this study, we employed B. phytofirmans PsJN to inoculate the Arabidopsis thaliana plants, and conducted the first investigation for its effects on the biomass yield, the anatomical organization of stems, the iron accumulation, and the pretreatment and enzymatic hydrolysis of harvested biomass. The results showed that the strain PsJN stimulated plant growth in the earlier period of plant development and enlarged the cell size of stem piths, and it also indeed enhanced the essential metals uptake and accumulation in host plants. Moreover, we found that the PsJN-inoculated plant biomass released more glucose and xylose after hot water pretreatment and subsequent co-saccharification, which provided a novel insight into development of lignocellulosic biofuels from renewable biomass resources.
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Affiliation(s)
- Shuai Zhao
- Bioscience Center, National Renewable Energy Laboratory Golden, CO, USA
| | - Hui Wei
- Bioscience Center, National Renewable Energy Laboratory Golden, CO, USA
| | - Chien-Yuan Lin
- Bioscience Center, National Renewable Energy Laboratory Golden, CO, USA
| | - Yining Zeng
- Bioscience Center, National Renewable Energy Laboratory Golden, CO, USA
| | - Melvin P Tucker
- National Bioenergy Center, National Renewable Energy Laboratory Golden, CO, USA
| | - Michael E Himmel
- Bioscience Center, National Renewable Energy Laboratory Golden, CO, USA
| | - Shi-You Ding
- Bioscience Center, National Renewable Energy Laboratory Golden, CO, USA
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25
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Rebets Y, Tokovenko B, Lushchyk I, Rückert C, Zaburannyi N, Bechthold A, Kalinowski J, Luzhetskyy A. Complete genome sequence of producer of the glycopeptide antibiotic Aculeximycin Kutzneria albida DSM 43870T, a representative of minor genus of Pseudonocardiaceae. BMC Genomics 2014; 15:885. [PMID: 25301375 PMCID: PMC4210621 DOI: 10.1186/1471-2164-15-885] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Accepted: 10/03/2014] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND Kutzneria is a representative of a rarely observed genus of the family Pseudonocardiaceae. Kutzneria species were initially placed in the Streptosporangiaceae genus and later reconsidered to be an independent genus of the Pseudonocardiaceae. Kutzneria albida is one of the eight known members of the genus. This strain is a unique producer of the glycosylated polyole macrolide aculeximycin which is active against both bacteria and fungi. Kutzneria albida genome sequencing and analysis allow a deeper understanding of evolution of this genus of Pseudonocardiaceae, provide new insight in the phylogeny of the genus, as well as decipher the hidden secondary metabolic potential of these rare actinobacteria. RESULTS To explore the biosynthetic potential of Kutzneria albida to its full extent, the complete genome was sequenced. With a size of 9,874,926 bp, coding for 8,822 genes, it stands alongside other Pseudonocardiaceae with large circular genomes. Genome analysis revealed 46 gene clusters potentially encoding secondary metabolite biosynthesis pathways. Two large genomic islands were identified, containing regions most enriched with secondary metabolism gene clusters. Large parts of this secondary metabolism "clustome" are dedicated to siderophores production. CONCLUSIONS Kutzneria albida is the first species of the genus Kutzneria with a completely sequenced genome. Genome sequencing allowed identifying the gene cluster responsible for the biosynthesis of aculeximycin, one of the largest known oligosaccharide-macrolide antibiotics. Moreover, the genome revealed 45 additional putative secondary metabolite gene clusters, suggesting a huge biosynthetic potential, which makes Kutzneria albida a very rich source of natural products. Comparison of the Kutzneria albida genome to genomes of other actinobacteria clearly shows its close relations with Pseudonocardiaceae in line with the taxonomic position of the genus.
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Affiliation(s)
- Yuriy Rebets
- />Helmholtz-Institute for Pharmaceutical Research Saarland, Saarland University Campus, Building C2.3, 66123 Saarbrücken, Germany
| | - Bogdan Tokovenko
- />Helmholtz-Institute for Pharmaceutical Research Saarland, Saarland University Campus, Building C2.3, 66123 Saarbrücken, Germany
| | - Igor Lushchyk
- />Helmholtz-Institute for Pharmaceutical Research Saarland, Saarland University Campus, Building C2.3, 66123 Saarbrücken, Germany
| | - Christian Rückert
- />Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615 Bielefeld, Germany
| | - Nestor Zaburannyi
- />Helmholtz-Institute for Pharmaceutical Research Saarland, Saarland University Campus, Building C2.3, 66123 Saarbrücken, Germany
| | - Andreas Bechthold
- />Institut für Pharmazeutische Biologie und Biotechnologie, Albert-Ludwigs Universität, Stefan-Meier-Strasse 19, 79104 Freiburg, Germany
| | - Jörn Kalinowski
- />Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615 Bielefeld, Germany
| | - Andriy Luzhetskyy
- />Helmholtz-Institute for Pharmaceutical Research Saarland, Saarland University Campus, Building C2.3, 66123 Saarbrücken, Germany
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Setser JW, Heemstra JR, Walsh CT, Drennan CL. Crystallographic evidence of drastic conformational changes in the active site of a flavin-dependent N-hydroxylase. Biochemistry 2014; 53:6063-77. [PMID: 25184411 PMCID: PMC4179590 DOI: 10.1021/bi500655q] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
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The soil actinomycete Kutzneria sp. 744 produces
a class of highly decorated hexadepsipeptides, which represent a new
chemical scaffold that has both antimicrobial and antifungal properties.
These natural products, known as kutznerides, are created via nonribosomal
peptide synthesis using various derivatized amino acids. The piperazic
acid moiety contained in the kutzneride scaffold, which is vital for
its antibiotic activity, has been shown to derive from the hydroxylated
product of l-ornithine, l-N5-hydroxyornithine. The production of this hydroxylated species
is catalyzed by the action of an FAD- and NAD(P)H-dependent N-hydroxylase known as KtzI. We have been able to structurally
characterize KtzI in several states along its catalytic trajectory,
and by pairing these snapshots with the biochemical and structural
data already available for this enzyme class, we propose a structurally
based reaction mechanism that includes novel conformational changes
of both the protein backbone and the flavin cofactor. Further, we
were able to recapitulate these conformational changes in the protein
crystal, displaying their chemical competence. Our series of structures,
with corroborating biochemical and spectroscopic data collected by
us and others, affords mechanistic insight into this relatively new
class of flavin-dependent hydroxylases and adds another layer to the
complexity of flavoenzymes.
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Affiliation(s)
- Jeremy W Setser
- Department of Chemistry, ‡Department of Biology, and §Howard Hughes Medical Institute, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
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27
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Frederick RE, Ojha S, Lamb A, Dubois JL. How pH modulates the reactivity and selectivity of a siderophore-associated flavin monooxygenase. Biochemistry 2014; 53:2007-16. [PMID: 24490904 PMCID: PMC3985866 DOI: 10.1021/bi401256b] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
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Flavin-containing
monooxygenases (FMOs) catalyze the oxygenation
of diverse organic molecules using O2, NADPH, and the flavin
adenine dinucleotide (FAD) cofactor. The fungal FMO SidA initiates
peptidic siderophore biosynthesis via the highly selective hydroxylation
of l-ornithine, while the related amino acid l-lysine
is a potent effector of reaction uncoupling to generate H2O2. We hypothesized that protonation states could critically
influence both substrate-selective hydroxylation and H2O2 release, and therefore undertook a study of SidA’s
pH-dependent reaction kinetics. Consistent with other FMOs that stabilize
a C4a-OO(H) intermediate, SidA’s reductive half reaction is
pH independent. The rate constant for the formation of the reactive
C4a-OO(H) intermediate from reduced SidA and O2 is likewise
independent of pH. However, the rate constants for C4a-OO(H) reactions,
either to eliminate H2O2 or to hydroxylate l-Orn, were strongly pH-dependent and influenced by the nature
of the bound amino acid. Solvent kinetic isotope effects of 6.6 ±
0.3 and 1.9 ± 0.2 were measured for the C4a-OOH/H2O2 conversion in the presence and absence of l-Lys, respectively. A model is proposed in which l-Lys accelerates
H2O2 release via an acid–base mechanism
and where side-chain position determines whether H2O2 or the hydroxylation product is observed.
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Affiliation(s)
- Rosanne E Frederick
- Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States
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28
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Ceccoli RD, Bianchi DA, Rial DV. Flavoprotein monooxygenases for oxidative biocatalysis: recombinant expression in microbial hosts and applications. Front Microbiol 2014; 5:25. [PMID: 24567729 PMCID: PMC3915288 DOI: 10.3389/fmicb.2014.00025] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 01/14/2014] [Indexed: 11/21/2022] Open
Abstract
External flavoprotein monooxygenases comprise a group of flavin-dependent oxidoreductases that catalyze the insertion of one atom of molecular oxygen into an organic substrate and the second atom is reduced to water. These enzymes are involved in a great number of metabolic pathways both in prokaryotes and eukaryotes. Flavoprotein monooxygenases have attracted the attention of researchers for several decades and the advent of recombinant DNA technology caused a great progress in the field. These enzymes are subjected to detailed biochemical and structural characterization and some of them are also regarded as appealing oxidative biocatalysts for the production of fine chemicals and valuable intermediates toward active pharmaceutical ingredients due to their high chemo-, stereo-, and regioselectivity. Here, we review the most representative reactions catalyzed both in vivo and in vitro by prototype flavoprotein monooxygenases, highlighting the strategies employed to produce them recombinantly, to enhance the yield of soluble proteins, and to improve cofactor regeneration in order to obtain versatile biocatalysts. Although we describe the most outstanding features of flavoprotein monooxygenases, we mainly focus on enzymes that were cloned, expressed and used for biocatalysis during the last years.
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Affiliation(s)
- Romina D Ceccoli
- Área Biología Molecular, Departamento de Ciencias Biológicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario CONICET, Rosario, Argentina
| | - Dario A Bianchi
- Instituto de Química Rosario (IQUIR, CONICET-UNR), Área Análisis de Medicamentos, Departamento de Química Orgánica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario Rosario, Argentina
| | - Daniela V Rial
- Área Biología Molecular, Departamento de Ciencias Biológicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario CONICET, Rosario, Argentina
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29
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Form follows function: structural and catalytic variation in the class a flavoprotein monooxygenases. Int J Mol Sci 2012; 13:15601-39. [PMID: 23443084 PMCID: PMC3546652 DOI: 10.3390/ijms131215601] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Revised: 11/08/2012] [Accepted: 11/09/2012] [Indexed: 12/02/2022] Open
Abstract
Flavoprotein monooxygenases (FPMOs) exhibit an array of mechanistic solutions to a common chemical objective; the monooxygenation of a target substrate. Each FPMO efficiently couples reduction of a flavin cofactor by NAD(P)H to oxygenation of the target substrate via a (hydro)peroxyflavin intermediate. This purpose of this review is to describe in detail the Class A flavoprotein hydroxylases (FPMO) in the context of the other FPMO classes (B–F). Both one and two component FPMOs are found in nature. Two-component enzymes require, in addition to the monooxygenase, the involvement of a reductase that first catalyzes the reduction of the flavin by NAD(P)H. The Class A and B FPMOs are single-component and manage to orchestrate the same net reaction within a single peptide. The Class A enzymes have, by some considerable margin, the most complete research record. These enzymes use choreographed movements of the flavin ring that facilitate access of the organic substrates to the active site, provide a means for interaction of NADPH with the flavin, offer a mechanism to sequester the dioxygen reduction chemistry from solvent and a means to release the product. The majority of the discrete catalytic events of the catalytic cycle can be observed directly in exquisite detail using spectrophotometric kinetic methods and many of the key mechanistic conclusions are further supported by structural data. This review attempts to compile each of the key observations made for both paradigm and newly discovered examples of Class A FPMOs into a complete catalytic description of one enzymatic turnover.
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30
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Schalk IJ, Guillon L. Pyoverdine biosynthesis and secretion in Pseudomonas aeruginosa: implications for metal homeostasis. Environ Microbiol 2012; 15:1661-73. [PMID: 23126435 DOI: 10.1111/1462-2920.12013] [Citation(s) in RCA: 142] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Revised: 09/17/2012] [Accepted: 09/26/2012] [Indexed: 02/03/2023]
Abstract
Pyoverdines are siderophores produced by fluorescent Pseudomonads to acquire iron. At least 60 different pyoverdines produced by diverse strains have been chemically characterized. They all consist of a dihydroquinoline-type chromophore linked to a peptide. These peptides are of various lengths and the sequences are strain specific. Pyoverdine biosynthesis in Pseudomonas aeruginosa and fluorescent Pseudomonads is a complex process involving at least 12 different proteins, starting in the cytoplasm and ending in the periplasm. The cellular localization of pyoverdine precursors was recently shown to be consistent with their biosynthetic enzymes. In the cytoplasm, pyoverdine appears to be assembled at the inner membrane and particularly at the old cell pole of the bacterium. Mature pyoverdine is uniformly distributed throughout the periplasm, like the periplasmic enzyme PvdQ. Secretion of pyoverdine involves a recently identified ATP-dependent efflux pump, PvdRT-OpmQ. This efflux system does not only secrete newly synthesized pyoverdine but also pyoverdine that already transported iron into the bacterial periplasm and any pyoverdine-metal complex other than ferri-pyoverdine present in the periplasm. This review considers how these new insights into pyoverdine biosynthesis and secretion contribute to our understanding of the role of pyoverdine in iron and metal homeostasis in fluorescent Pseudomonads.
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Affiliation(s)
- Isabelle J Schalk
- UMR 7242, Université de Strasbourg-CNRS, ESBS, Blvd Sébastien Brant, F-67413 Illkirch, Strasbourg, France.
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31
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Neumann CS, Jiang W, Heemstra JR, Gontang EA, Kolter R, Walsh CT. Biosynthesis of piperazic acid via N5-hydroxy-ornithine in Kutzneria spp. 744. Chembiochem 2012; 13:972-6. [PMID: 22522643 DOI: 10.1002/cbic.201200054] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Indexed: 11/10/2022]
Abstract
Which came first? We have investigated the biosynthesis of the piperazic acid (Piz) building blocks in the kutzneride family of metabolites. The flavin-dependent oxygenase KtzI was shown to convert ornithine to N(5)-OH-Orn. LC-MS/MS showed (13)C(5)-labeled versions of these two amino acids to be direct precursors of piperazic acid in vivo.
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Affiliation(s)
- Christopher S Neumann
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA
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32
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Montersino S, van Berkel WJH. Functional annotation and characterization of 3-hydroxybenzoate 6-hydroxylase from Rhodococcus jostii RHA1. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2011; 1824:433-42. [PMID: 22207056 DOI: 10.1016/j.bbapap.2011.12.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2011] [Revised: 12/09/2011] [Accepted: 12/14/2011] [Indexed: 12/11/2022]
Abstract
The genome of Rhodococcus jostii RHA1 contains an unusually large number of oxygenase encoding genes. Many of these genes have yet an unknown function, implying that a notable part of the biochemical and catabolic biodiversity of this Gram-positive soil actinomycete is still elusive. Here we present a multiple sequence alignment and phylogenetic analysis of putative R. jostii RHA1 flavoprotein hydroxylases. Out of 18 candidate sequences, three hydroxylases are absent in other available Rhodococcus genomes. In addition, we report the biochemical characterization of 3-hydroxybenzoate 6-hydroxylase (3HB6H), a gentisate-producing enzyme originally mis-annotated as salicylate hydroxylase. R. jostii RHA1 3HB6H expressed in Escherichia coli is a homodimer with each 47kDa subunit containing a non-covalently bound FAD cofactor. The enzyme has a pH optimum around pH 8.3 and prefers NADH as external electron donor. 3HB6H is active with a series of 3-hydroxybenzoate analogues, bearing substituents in ortho- or meta-position of the aromatic ring. Gentisate, the physiological product, is a non-substrate effector of 3HB6H. This compound is not hydroxylated but strongly stimulates the NADH oxidase activity of the enzyme.
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33
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Olucha J, Lamb AL. Mechanistic and structural studies of the N-hydroxylating flavoprotein monooxygenases. Bioorg Chem 2011; 39:171-7. [PMID: 21871647 PMCID: PMC3188341 DOI: 10.1016/j.bioorg.2011.07.006] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Revised: 07/28/2011] [Accepted: 07/29/2011] [Indexed: 10/17/2022]
Abstract
The N-hydroxylating flavoprotein monooxygenases are siderophore biosynthetic enzymes that catalyze the hydroxylation of the sidechain amino-group of ornithine or lysine or the primary amino-group of putrescine. This hydroxylated product is subsequently formylated or acylated and incorporated into the siderophore. Importantly, the modified amino-group is a hydroxamate and serves as an iron chelating moiety in the siderophore. This review describes recent work to characterize the ornithine hydroxylases from Pseudomonas aeruginosa (PvdA) and Aspergillus fumigatus (SidA) and the lysine hydroxylase from Escherichia coli (IucD). This includes summaries of steady and transient state kinetic data for all three enzymes and the X-ray crystallographic structure of PvdA.
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Affiliation(s)
- Jose Olucha
- Molecular Biosciences, University of Kansas, 1200 Sunnyside Ave, Lawrence, Kansas
| | - Audrey L. Lamb
- Molecular Biosciences, University of Kansas, 1200 Sunnyside Ave, Lawrence, Kansas
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34
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Olucha J, Meneely KM, Chilton AS, Lamb AL. Two structures of an N-hydroxylating flavoprotein monooxygenase: ornithine hydroxylase from Pseudomonas aeruginosa. J Biol Chem 2011; 286:31789-98. [PMID: 21757711 PMCID: PMC3173084 DOI: 10.1074/jbc.m111.265876] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Revised: 07/02/2011] [Indexed: 11/06/2022] Open
Abstract
The ornithine hydroxylase from Pseudomonas aeruginosa (PvdA) catalyzes the FAD-dependent hydroxylation of the side chain amine of ornithine, which is subsequently formylated to generate the iron-chelating hydroxamates of the siderophore pyoverdin. PvdA belongs to the class B flavoprotein monooxygenases, which catalyze the oxidation of substrates using NADPH as the electron donor and molecular oxygen. Class B enzymes include the well studied flavin-containing monooxygenases and Baeyer-Villiger monooxygenases. The first two structures of a class B N-hydroxylating monooxygenase were determined with FAD in oxidized (1.9 Å resolution) and reduced (3.03 Å resolution) states. PvdA has the two expected Rossmann-like dinucleotide-binding domains for FAD and NADPH and also a substrate-binding domain, with the active site at the interface between the three domains. The structures have NADP(H) and (hydroxy)ornithine bound in a solvent-exposed active site, providing structural evidence for substrate and co-substrate specificity and the inability of PvdA to bind FAD tightly. Structural and biochemical evidence indicates that NADP(+) remains bound throughout the oxidative half-reaction, which is proposed to shelter the flavin intermediates from solvent and thereby prevent uncoupling of NADPH oxidation from hydroxylated product formation.
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Affiliation(s)
- Jose Olucha
- From the Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045
| | - Kathleen M. Meneely
- From the Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045
| | - Annemarie S. Chilton
- From the Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045
| | - Audrey L. Lamb
- From the Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045
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35
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Frederick RE, Mayfield JA, DuBois JL. Regulated O2 activation in flavin-dependent monooxygenases. J Am Chem Soc 2011; 133:12338-41. [PMID: 21774554 PMCID: PMC3391563 DOI: 10.1021/ja203397s] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Flavin-dependent monooxygenases (FMOs) are involved in important biosynthetic pathways in diverse organisms, including production of the siderophores used for the import and storage of essential iron in serious pathogens. We have shown that the FMO from Aspergillus fumigatus, an ornithine monooxygenase (Af-OMO), is mechanistically similar to its well-studied distant homologues from mammalian liver. The latter are highly promiscuous in their choice of substrates, while Af-OMO is unusually specific. This presents a puzzle: how do Af-OMO and other FMOs of the biosynthetic classes achieve such specificity? We have discovered substantial enhancement in the rate of O(2) activation in Af-OMO in the presence of L-arginine, which acts as a small molecule regulator. Such protein-level regulation could help explain how this and related biosynthetic FMOs manage to couple O(2) activation and substrate hydroxylation to each other and to the appropriate cellular conditions. Given the essentiality of Fe to Af and the avirulence of the Af-OMO gene knock out, inhibitors of Af-OMO are likely to be drug targets against this medically intractable pathogen.
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Affiliation(s)
- Rosanne E. Frederick
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Jeffery A. Mayfield
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Jennifer L. DuBois
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
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36
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Matthijs S, Laus G, Meyer JM, Abbaspour-Tehrani K, Schäfer M, Budzikiewicz H, Cornelis P. Siderophore-mediated iron acquisition in the entomopathogenic bacterium Pseudomonas entomophila L48 and its close relative Pseudomonas putida KT2440. Biometals 2011; 22:951-64. [PMID: 19459056 DOI: 10.1007/s10534-009-9247-y] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2008] [Accepted: 05/05/2009] [Indexed: 11/26/2022]
Abstract
Pseudomonas entomophila L48 is a recently identified entomopathogenic bacterium which, upon ingestion, kills Drosophila melanogaster, and is closely related to P. putida. The complete genome of this species has been sequenced and therefore a genomic, genetic and structural analysis of the siderophore-mediated iron acquisition was undertaken. P. entomophila produces two siderophores, a structurally new and unique pyoverdine and the secondary siderophore pseudomonine, already described in P. fluorescens species. Structural analysis of the pyoverdine produced by the closely related P. putida KT2440 showed that this strain produces an already characterised pyoverdine, but different from P. entomophila, and no evidence was found for the production of a second siderophore. Growth stimulation assays with heterologous pyoverdines demonstrated that P. entomophila is able to utilize a large variety of structurally distinct pyoverdines produced by other Pseudomonas species. In contrast, P. putida KT2440 is able to utilize only its own pyoverdine and the pyoverdine produced by P. syringae LMG 1247. Our data suggest that although closely related, P. entomophila is a more efficient competitor for iron than P. putida.
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Affiliation(s)
- Sandra Matthijs
- Laboratory of Microbial Interactions, Department of Molecular and Cellular Interactions, Flanders Interuniversity Institute for Biotechnology, Vrije Universiteit Brussel, Building E, Pleinlaan 2, 1050 Brussels, Belgium
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37
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Robbel L, Helmetag V, Knappe TA, Marahiel MA. Consecutive enzymatic modification of ornithine generates the hydroxamate moieties of the siderophore erythrochelin. Biochemistry 2011; 50:6073-80. [PMID: 21650455 DOI: 10.1021/bi200699x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Biosynthesis of the hydroxamate-type siderophore erythrochelin requires the generation of δ-N-acetyl-δ-N-hydroxy-L-ornithine (L-haOrn), which is incorporated into the tetrapeptide at positions 1 and 4. Bioinformatic analysis revealed the FAD-dependent monooxygenase EtcB and the bifunctional malonyl-CoA decarboxylase/acetyltransferase Mcd to be putatively involved in the generation of L-haOrn. To investigate if EtcB and Mcd constitute a two-enzyme pathway for the biosynthesis of L-haOrn, they were produced in a recombinant manner and subjected to biochemical studies in vitro. Hydroxylation assays employing recombinant EtcB gave rise to δ-N-hydroxy-L-ornithine (L-hOrn) and confirmed the enzyme to be involved in building block assembly. Acetylation assays were carried out by incubating L-hOrn with recombinant Mcd and malonyl-CoA as the acetyl group donor. Substrate turnover was increased by substituting malonyl-CoA with acetyl-CoA, bypassing the decarboxylation reaction which represents the rate-limiting step. Consecutive enzymatic synthesis of L-haOrn was accomplished in coupled assays employing both the L-ornithine hydroxylase and Mcd. In summary, a biosynthetic route for the generation of δ-N-acetyl-δ-N-hydroxy-L-ornithine starting from L-ornithine has been established in vitro by tandem action of the FAD-dependent monooxygenase EtcB and the bifunctional malonyl-CoA decarboxylase/acetyltransferase Mcd.
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Affiliation(s)
- Lars Robbel
- Department of Chemistry/Biochemistry, Philipps-University Marburg, Hans-Meerwein-Strasse, D-35032 Marburg, Germany
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38
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Nwugo CC, Gaddy JA, Zimbler DL, Actis LA. Deciphering the iron response in Acinetobacter baumannii: A proteomics approach. J Proteomics 2011; 74:44-58. [PMID: 20692388 DOI: 10.1016/2fj.jprot.2010.07.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2010] [Revised: 06/22/2010] [Accepted: 07/27/2010] [Indexed: 05/22/2023]
Abstract
Iron is an essential nutrient that plays a role in bacterial differential gene expression and protein production. Accordingly, the comparative analysis of total lysate and outer membrane fractions isolated from A. baumannii ATCC 19606(T) cells cultured under iron-rich and -chelated conditions using 2-D gel electrophoresis-mass spectrometry resulted in the identification of 58 protein spots differentially produced. While 19 and 35 of them represent iron-repressed and iron-induced protein spots, respectively, four other spots represent a metal chelation response unrelated to iron. Most of the iron-repressed protein spots represent outer membrane siderophore receptors, some of which could be involved in the utilization of siderophores produced by other bacteria. The iron-induced protein spots represent a wide range of proteins including those involved in iron storage, such as Bfr, metabolic and energy processes, such as AcnA, AcnB, GlyA, SdhA, and SodB, as well as lipid biosynthesis. The detection of an iron-regulated Hfq ortholog indicates that iron regulation in this bacterium could be mediated by Fur and small RNAs as described in other bacteria. The iron-induced production of OmpA suggests this protein plays a role in iron metabolism as shown by the diminished ability of an isogenic OmpA deficient derivative to grow under iron-chelated conditions.
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Affiliation(s)
- Chika C Nwugo
- Department of Microbiology, Miami University, Oxford, Ohio, USA
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39
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Nwugo CC, Gaddy JA, Zimbler DL, Actis LA. Deciphering the iron response in Acinetobacter baumannii: A proteomics approach. J Proteomics 2010; 74:44-58. [PMID: 20692388 DOI: 10.1016/j.jprot.2010.07.010] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2010] [Revised: 06/22/2010] [Accepted: 07/27/2010] [Indexed: 12/14/2022]
Abstract
Iron is an essential nutrient that plays a role in bacterial differential gene expression and protein production. Accordingly, the comparative analysis of total lysate and outer membrane fractions isolated from A. baumannii ATCC 19606(T) cells cultured under iron-rich and -chelated conditions using 2-D gel electrophoresis-mass spectrometry resulted in the identification of 58 protein spots differentially produced. While 19 and 35 of them represent iron-repressed and iron-induced protein spots, respectively, four other spots represent a metal chelation response unrelated to iron. Most of the iron-repressed protein spots represent outer membrane siderophore receptors, some of which could be involved in the utilization of siderophores produced by other bacteria. The iron-induced protein spots represent a wide range of proteins including those involved in iron storage, such as Bfr, metabolic and energy processes, such as AcnA, AcnB, GlyA, SdhA, and SodB, as well as lipid biosynthesis. The detection of an iron-regulated Hfq ortholog indicates that iron regulation in this bacterium could be mediated by Fur and small RNAs as described in other bacteria. The iron-induced production of OmpA suggests this protein plays a role in iron metabolism as shown by the diminished ability of an isogenic OmpA deficient derivative to grow under iron-chelated conditions.
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Affiliation(s)
- Chika C Nwugo
- Department of Microbiology, Miami University, Oxford, Ohio, USA
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Mayfield JA, Frederick RE, Streit BR, Wencewicz TA, Ballou DP, DuBois JL. Comprehensive spectroscopic, steady state, and transient kinetic studies of a representative siderophore-associated flavin monooxygenase. J Biol Chem 2010; 285:30375-88. [PMID: 20650894 DOI: 10.1074/jbc.m110.157578] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Many siderophores used for the uptake and intracellular storage of essential iron contain hydroxamate chelating groups. Their biosyntheses are typically initiated by hydroxylation of the primary amine side chains of l-ornithine or l-lysine. This reaction is catalyzed by members of a widespread family of FAD-dependent monooxygenases. Here the kinetic mechanism for a representative family member has been extensively characterized by steady state and transient kinetic methods, using heterologously expressed N(5)-l-ornithine monooxygenase from the pathogenic fungus Aspergillus fumigatus. Spectroscopic data and kinetic analyses suggest a model in which a molecule of hydroxylatable substrate serves as an activator for the reaction of the reduced flavin and O(2). The rate acceleration is only ∼5-fold, a mild effect of substrate on formation of the C4a-hydroperoxide that does not influence the overall rate of turnover. The effect is also observed with the bacterial ornithine monooxygenase PvdA. The C4a-hydroperoxide is stabilized in the absence of hydroxylatable substrate by the presence of bound NADP(+) (t(½) = 33 min, 25 °C, pH 8). NADP(+) therefore is a likely regulator of O(2) and substrate reactivity in the siderophore-associated monooxygenases. Aside from the activating effect of the hydroxylatable substrate, the siderophore-associated monooxygenases share a kinetic mechanism with the hepatic microsomal flavin monooxygenases and bacterial Baeyer-Villiger monooxygenases, with which they share only moderate sequence homology and from which they are distinguished by their acute substrate specificity. The remarkable specificity of the N(5)-l-ornithine monooxygenase-catalyzed reaction suggests added means of reaction control beyond those documented in related well characterized flavoenzymes.
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Affiliation(s)
- Jeffery A Mayfield
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA
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Synthesis of the siderophore pyoverdine in Pseudomonas aeruginosa involves a periplasmic maturation. Amino Acids 2009; 38:1447-59. [PMID: 19787431 DOI: 10.1007/s00726-009-0358-0] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2009] [Accepted: 09/15/2009] [Indexed: 10/20/2022]
Abstract
Pyoverdines, the main siderophores produced by fluorescent Pseudomonads, comprise a fluorescent dihydroxyquinoline chromophore attached to a strain-specific peptide. These molecules are thought to be synthesized as non-fluorescent precursor peptides that are then modified to give functional pyoverdines. Using the fluorescent properties of PVDI, the pyoverdine produced by Pseudomonas aeruginosa PAO1, we were able to show that PVDI was not present in the cytoplasm of the bacteria, but large amounts of a fluorescent PVDI precursor PVDIp were stored in the periplasm. Like PVDI, PVDIp is able to transport iron into P. aeruginosa cells. Mutation of genes encoding the periplasmic PvdN, PvdO and PvdP proteins prevented accumulation of PVDIp in the periplasm and secretion of PVDI into the growth medium, indicating that these three enzymes are involved in PVDI synthesis. Mutation of the gene encoding PvdQ resulted in the presence of fluorescent PVDI precursor in the periplasm and secretion of a functional fluorescent siderophore that had different isoelectric properties to PVDI, suggesting a role for PvdQ in the periplasmic maturation of PVDI. Mutation of the gene encoding the export ABC transporter PvdE prevented PVDI production and accumulation of PVDIp in the periplasm. These data are consistent with a model in which a PVDI precursor peptide is synthesized in the cytoplasm and exported to the periplasm by PvdE where siderophore maturation, including formation of the chromophore moiety, occurs in a process involving the PvdN, PvdO, PvdP and PvdQ proteins.
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Meneely KM, Barr EW, Bollinger JM, Lamb AL. Kinetic mechanism of ornithine hydroxylase (PvdA) from Pseudomonas aeruginosa: substrate triggering of O2 addition but not flavin reduction. Biochemistry 2009; 48:4371-6. [PMID: 19368334 DOI: 10.1021/bi900442z] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PvdA catalyzes the hydroxylation of the side chain primary amine of ornithine in the initial step of the biosynthesis of the Pseudomonas aeruginosa siderophore pyoverdin. The reaction requires FAD, NADPH, and O(2). PvdA uses the same cosubstrates as several flavin-dependent hydroxylases that differ one from another in the kinetic mechanisms of their oxidative and reductive half-reactions. Therefore, the mechanism of PvdA was determined by absorption stopped-flow experiments. By contrast to some flavin-dependent hydroxylases (notably, p-hydroxybenzoate hydroxylase), binding of the hydroxylation target is not required to trigger reduction of the flavin by NADPH: the reductive half-reaction is equally facile in the presence and absence of ornithine. Reaction of O(2) with FADH(2) in the oxidative half-reaction is accelerated by ornithine 80-fold, providing a mechanism by which PvdA can ensure coupling of NADPH and ornithine oxidation. In the presence of ornithine, the expected C(4a)-hydroperoxyflavin intermediate with 390 nm absorption accumulates and decays to the C(4a)-hydroxyflavin in a kinetically competent fashion. The slower oxidative half-reaction that occurs in the absence of ornithine involves accumulation of an oxygenated flavin species and two subsequent states that are tentatively assigned as C(4a)-peroxy- and C(4a)-hydroperoxyflavin intermediates and the oxidized flavin. The enzyme generates stoichiometric hydrogen peroxide in lieu of hydroxyornithine. The data suggest that PvdA employs a kinetic mechanism that is a hybrid of those previously documented for other flavin-dependent hydroxylases.
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Affiliation(s)
- Kathleen M Meneely
- Department of Molecular Biosciences, University of Kansas, 1200 Sunnyside Avenue, Lawrence, Kansas 66045, USA
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Imperi F, Putignani L, Tiburzi F, Ambrosi C, Cipollone R, Ascenzi P, Visca P. Membrane-association determinants of the omega-amino acid monooxygenase PvdA, a pyoverdine biosynthetic enzyme from Pseudomonas aeruginosa. MICROBIOLOGY-SGM 2008; 154:2804-2813. [PMID: 18757814 DOI: 10.1099/mic.0.2008/018804-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The L-ornithine N(delta)-oxygenase PvdA catalyses the N(delta)-hydroxylation of L-ornithine in many Pseudomonas spp., and thus provides an essential enzymic function in the biogenesis of the pyoverdine siderophore. Here, we report a detailed analysis of the membrane topology of the PvdA enzyme from the bacterial pathogen Pseudomonas aeruginosa. Membrane topogenic determinants of PvdA were identified by computational analysis, and verified in Escherichia coli by constructing a series of translational fusions between PvdA and the PhoA (alkaline phosphatase) reporter enzyme. The inferred topological model resembled a eukaryotic reverse signal-anchor (type III) protein, with a single N-terminal domain anchored to the inner membrane, and the bulk of the protein spanning the cytosol. According to this model, the predicted transmembrane region should overlap the putative FAD-binding site. Cell fractionation and proteinase K accessibility experiments in P. aeruginosa confirmed the membrane-bound nature of PvdA, but excluded the transmembrane topology of its N-terminal hydrophobic region. Mutational analysis of PvdA, and complementation assays in a P. aeruginosa DeltapvdA mutant, demonstrated the dual (structural and functional) role of the PvdA N-terminal domain.
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Affiliation(s)
- Francesco Imperi
- National Institute for Infectious Diseases IRCCS, 'Lazzaro Spallanzani', Via Portuense 292, I-00149 Rome, Italy.,Department of Biology, University 'Roma Tre', Viale G. Marconi 446, I-00146 Rome, Italy
| | - Lorenza Putignani
- National Institute for Infectious Diseases IRCCS, 'Lazzaro Spallanzani', Via Portuense 292, I-00149 Rome, Italy
| | - Federica Tiburzi
- National Institute for Infectious Diseases IRCCS, 'Lazzaro Spallanzani', Via Portuense 292, I-00149 Rome, Italy.,Department of Biology, University 'Roma Tre', Viale G. Marconi 446, I-00146 Rome, Italy
| | - Cecilia Ambrosi
- Department of Biology, University 'Roma Tre', Viale G. Marconi 446, I-00146 Rome, Italy
| | - Rita Cipollone
- Department of Biology, University 'Roma Tre', Viale G. Marconi 446, I-00146 Rome, Italy
| | - Paolo Ascenzi
- National Institute for Infectious Diseases IRCCS, 'Lazzaro Spallanzani', Via Portuense 292, I-00149 Rome, Italy.,Department of Biology, University 'Roma Tre', Viale G. Marconi 446, I-00146 Rome, Italy
| | - Paolo Visca
- National Institute for Infectious Diseases IRCCS, 'Lazzaro Spallanzani', Via Portuense 292, I-00149 Rome, Italy.,Department of Biology, University 'Roma Tre', Viale G. Marconi 446, I-00146 Rome, Italy
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Pohlmann V, Marahiel MA. Delta-amino group hydroxylation of L-ornithine during coelichelin biosynthesis. Org Biomol Chem 2008; 6:1843-8. [PMID: 18452021 DOI: 10.1039/b801016a] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The nonribosomally produced hydroxamate siderophore coelichelin from Streptomyces coelicolor contains the nonproteinogenic amino acids N(5)-hydroxyornithine and N(5)-hydroxyformylornithine that are important for iron assembly. The hydroxylation of the delta-amino group of L-ornithine is catalyzed by the flavin-dependent monooxygenase CchB. During the redox reaction nicotinamide adenine dinucleotide phosphate (NADPH) and molecular oxygen are consumed and flavin adenine dinucleotide (FAD) is needed as a cofactor. During this work the monooxygenase was biochemically characterized and it could be shown that the hydroxylation of l-ornithine is most likely the first step in the biosynthesis of the siderophore coelichelin.
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Affiliation(s)
- Verena Pohlmann
- Chemistry/Biochemistry Department, Philipps-University Marburg, Hans-Meerwein-Strasse, 35032 Marburg, Germany
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Meneely KM, Lamb AL. Biochemical characterization of a flavin adenine dinucleotide-dependent monooxygenase, ornithine hydroxylase from Pseudomonas aeruginosa, suggests a novel reaction mechanism. Biochemistry 2007; 46:11930-7. [PMID: 17900176 PMCID: PMC2597334 DOI: 10.1021/bi700932q] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Pyoverdin is the hydroxamate siderophore produced by the opportunistic pathogen Pseudomonas aeruginosa under the iron-limiting conditions of the human host. This siderophore includes derivatives of ornithine in the peptide backbone that serve as iron chelators. PvdA is the ornithine hydroxylase, which performs the first enzymatic step in preparation of these derivatives. PvdA requires both flavin adenine dinucleotide (FAD) and nicotinamide adenine dinucleotide phosphate (NADPH) for activity; it was found to be a soluble monomer most active at pH 8.0. The enzyme demonstrated Michaelis-Menten kinetics in an NADPH oxidation assay, but a hydroxylation assay indicated substrate inhibition at high ornithine concentration. PvdA is highly specific for both substrate and coenzyme, and lysine was shown to be a nonsubstrate effector and mixed inhibitor of the enzyme with respect to ornithine. Chloride is a mixed inhibitor of PvdA with respect to ornithine but a competitive inhibitor with respect to NADPH, and a bulky mercurial compound (p-chloromercuribenzoate) is a mixed inhibitor with respect to ornithine. Steady-state experiments indicate that PvdA/FAD forms a ternary complex with NADPH and ornithine for catalysis. PvdA in the absence of ornithine shows slow substrate-independent flavin reduction by NADPH. Biochemical comparison of PvdA to p-hydroxybenzoate hydroxylase (PHBH, from Pseudomonas fluorescens) and flavin-containing monooxygenases (FMOs, from Schizosaccharomyces pombe and hog liver microsomes) leads to the hypothesis that PvdA catalysis proceeds by a novel reaction mechanism.
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Affiliation(s)
| | - Audrey L. Lamb
- corresponding author; phone: (785)864-5075; fax: (785)864-5294;
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Abstract
Flavoenzymes are colourful oxidoreductases that catalyze a large variety of different types of reactions. Flavoenzymes have been extensively studied for their structural and mechanistic properties and are gaining momentum in industrial biocatalytic applications. Some of these enzymes catalyze the oxidative modification of protein substrates. New insights in oxidative flavoenzymes and in particular in novel family members point towards their potential application in the pharmaceutical, fine-chemical and food industries.
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Affiliation(s)
- Vivi Joosten
- Laboratory of Biochemistry, Wageningen University Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
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