1
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Konkel Z, Kubatko L, Slot JC. CLOCI: unveiling cryptic fungal gene clusters with generalized detection. Nucleic Acids Res 2024; 52:e75. [PMID: 39016185 PMCID: PMC11381361 DOI: 10.1093/nar/gkae625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 07/01/2024] [Accepted: 07/10/2024] [Indexed: 07/18/2024] Open
Abstract
Gene clusters are genomic loci that contain multiple genes that are functionally and genetically linked. Gene clusters collectively encode diverse functions, including small molecule biosynthesis, nutrient assimilation, metabolite degradation, and production of proteins essential for growth and development. Identifying gene clusters is a powerful tool for small molecule discovery and provides insight into the ecology and evolution of organisms. Current detection algorithms focus on canonical 'core' biosynthetic functions many gene clusters encode, while overlooking uncommon or unknown cluster classes. These overlooked clusters are a potential source of novel natural products and comprise an untold portion of overall gene cluster repertoires. Unbiased, function-agnostic detection algorithms therefore provide an opportunity to reveal novel classes of gene clusters and more precisely define genome organization. We present CLOCI (Co-occurrence Locus and Orthologous Cluster Identifier), an algorithm that identifies gene clusters using multiple proxies of selection for coordinated gene evolution. Our approach generalizes gene cluster detection and gene cluster family circumscription, improves detection of multiple known functional classes, and unveils non-canonical gene clusters. CLOCI is suitable for genome-enabled small molecule mining, and presents an easily tunable approach for delineating gene cluster families and homologous loci.
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Affiliation(s)
- Zachary Konkel
- Department of Plant Pathology, The Ohio State University, Columbus, OH 43210, USA
- Center for Applied Plant Sciences, The Ohio State University, Columbus, OH 43210, USA
| | - Laura Kubatko
- Department of Ecology and Organismal Biology, The Ohio State University, Columbus, OH 43210, USA
- Department of Statistics, The Ohio State University, Columbus, OH 43210, USA
| | - Jason C Slot
- Department of Plant Pathology, The Ohio State University, Columbus, OH 43210, USA
- Center for Applied Plant Sciences, The Ohio State University, Columbus, OH 43210, USA
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2
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Rissi DV, Ijaz M, Baschien C. Comparative Genomics of Fungi in Nectriaceae Reveals Their Environmental Adaptation and Conservation Strategies. J Fungi (Basel) 2024; 10:632. [PMID: 39330392 PMCID: PMC11433043 DOI: 10.3390/jof10090632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2024] [Revised: 08/27/2024] [Accepted: 08/29/2024] [Indexed: 09/28/2024] Open
Abstract
This study presents the first genome assembly of the freshwater saprobe fungus Neonectria lugdunensis and a comprehensive phylogenomics analysis of the Nectriaceae family, examining genomic traits according to fungal lifestyles. The Nectriaceae family, one of the largest in Hypocreales, includes fungi with significant ecological roles and economic importance as plant pathogens, endophytes, and saprobes. The phylogenomics analysis identified 2684 single-copy orthologs, providing a robust evolutionary framework for the Nectriaceae family. We analyzed the genomic characteristics of 17 Nectriaceae genomes, focusing on their carbohydrate-active enzymes (CAZymes), biosynthetic gene clusters (BGCs), and adaptations to environmental temperatures. Our results highlight the adaptation mechanisms of N. lugdunensis, emphasizing its capabilities for plant litter degradation and enzyme activity in varying temperatures. The comparative genomics of different Nectriaceae lifestyles revealed significant differences in genome size, gene content, repetitive elements, and secondary metabolite production. Endophytes exhibited larger genomes, more effector proteins, and BGCs, while plant pathogens had higher thermo-adapted protein counts, suggesting greater resilience to global warming. In contrast, the freshwater saprobe shows less adaptation to warmer temperatures and is important for conservation goals. This study underscores the importance of understanding fungal genomic adaptations to predict ecosystem impacts and conservation targets in the face of climate change.
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Affiliation(s)
- Daniel Vasconcelos Rissi
- Leibniz Institute-DSMZ, German Collection of Microorganisms and Cell Cultures, 38124 Braunschweig, Germany
| | - Maham Ijaz
- Leibniz Institute-DSMZ, German Collection of Microorganisms and Cell Cultures, 38124 Braunschweig, Germany
| | - Christiane Baschien
- Leibniz Institute-DSMZ, German Collection of Microorganisms and Cell Cultures, 38124 Braunschweig, Germany
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3
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Kortsinoglou AM, Wood MJ, Myridakis AI, Andrikopoulos M, Roussis A, Eastwood D, Butt T, Kouvelis VN. Comparative genomics of Metarhizium brunneum strains V275 and ARSEF 4556: unraveling intraspecies diversity. G3 (BETHESDA, MD.) 2024:jkae190. [PMID: 39210673 DOI: 10.1093/g3journal/jkae190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2024] [Accepted: 07/31/2024] [Indexed: 09/04/2024]
Abstract
Entomopathogenic fungi belonging to the Order Hypocreales are renowned for their ability to infect and kill insect hosts, while their endophytic mode of life and the beneficial rhizosphere effects on plant hosts have only been recently recognized. Understanding the molecular mechanisms underlying their different lifestyles could optimize their potential as both biocontrol and biofertilizer agents, as well as the wider appreciation of niche plasticity in fungal ecology. This study describes the comprehensive whole genome sequencing and analysis of one of the most effective entomopathogenic and endophytic EPF strains, Metarhizium brunneum V275 (commercially known as Lalguard Met52), achieved through Nanopore and Illumina reads. Comparative genomics for exploring intraspecies variability and analyses of key gene sets were conducted with a second effective EPF strain, M. brunneum ARSEF 4556. The search for strain- or species-specific genes was extended to M. brunneum strain ARSEF 3297 and other species of genus Metarhizium, to identify molecular mechanisms and putative key genome adaptations associated with mode of life differences. Genome size differed significantly, with M. brunneum V275 having the largest genome amongst M. brunneum strains sequenced to date. Genome analyses revealed an abundance of plant-degrading enzymes, plant colonization-associated genes, and intriguing intraspecies variations regarding their predicted secondary metabolic compounds and the number and localization of Transposable Elements. The potential significance of the differences found between closely related endophytic and entomopathogenic fungi, regarding plant growth-promoting and entomopathogenic abilities, are discussed, enhancing our understanding of their diverse functionalities and putative applications in agriculture and ecology.
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Affiliation(s)
- Alexandra M Kortsinoglou
- Section of Genetics and Biotechnology, Department of Biology, National and Kapodistrian University of Athens, 15771 Athens, Greece
| | - Martyn J Wood
- Department of Biosciences, Faculty of Science and Engineering, Swansea University, Singleton Park, SA2 8PP, Swansea, UK
| | - Antonis I Myridakis
- Section of Genetics and Biotechnology, Department of Biology, National and Kapodistrian University of Athens, 15771 Athens, Greece
| | - Marios Andrikopoulos
- Section of Genetics and Biotechnology, Department of Biology, National and Kapodistrian University of Athens, 15771 Athens, Greece
| | - Andreas Roussis
- Section of Botany, Department of Biology, National and Kapodistrian University of Athens, 15784 Athens, Greece
| | - Dan Eastwood
- Department of Biosciences, Faculty of Science and Engineering, Swansea University, Singleton Park, SA2 8PP, Swansea, UK
| | - Tariq Butt
- Department of Biosciences, Faculty of Science and Engineering, Swansea University, Singleton Park, SA2 8PP, Swansea, UK
| | - Vassili N Kouvelis
- Section of Genetics and Biotechnology, Department of Biology, National and Kapodistrian University of Athens, 15771 Athens, Greece
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4
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Seo HW, Wassano NS, Amir Rawa MS, Nickles GR, Damasio A, Keller NP. A Timeline of Biosynthetic Gene Cluster Discovery in Aspergillus fumigatus: From Characterization to Future Perspectives. J Fungi (Basel) 2024; 10:266. [PMID: 38667937 PMCID: PMC11051388 DOI: 10.3390/jof10040266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 03/27/2024] [Accepted: 03/28/2024] [Indexed: 04/28/2024] Open
Abstract
In 1999, the first biosynthetic gene cluster (BGC), synthesizing the virulence factor DHN melanin, was characterized in Aspergillus fumigatus. Since then, 19 additional BGCs have been linked to specific secondary metabolites (SMs) in this species. Here, we provide a comprehensive timeline of A. fumigatus BGC discovery and find that initial advances centered around the commonly expressed SMs where chemical structure informed rationale identification of the producing BGC (e.g., gliotoxin, fumigaclavine, fumitremorgin, pseurotin A, helvolic acid, fumiquinazoline). Further advances followed the transcriptional profiling of a ΔlaeA mutant, which aided in the identification of endocrocin, fumagillin, hexadehydroastechrome, trypacidin, and fumisoquin BGCs. These SMs and their precursors are the commonly produced metabolites in most A. fumigatus studies. Characterization of other BGC/SM pairs required additional efforts, such as induction treatments, including co-culture with bacteria (fumicycline/neosartoricin, fumigermin) or growth under copper starvation (fumivaline, fumicicolin). Finally, four BGC/SM pairs were discovered via overexpression technologies, including the use of heterologous hosts (fumicycline/neosartoricin, fumihopaside, sphingofungin, and sartorypyrone). Initial analysis of the two most studied A. fumigatus isolates, Af293 and A1160, suggested that both harbored ca. 34-36 BGCs. However, an examination of 264 available genomes of A. fumigatus shows up to 20 additional BGCs, with some strains showing considerable variations in BGC number and composition. These new BGCs present a new frontier in the future of secondary metabolism characterization in this important species.
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Affiliation(s)
- Hye-Won Seo
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, USA; (H.-W.S.); (N.S.W.); (M.S.A.R.); (G.R.N.)
| | - Natalia S. Wassano
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, USA; (H.-W.S.); (N.S.W.); (M.S.A.R.); (G.R.N.)
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), São Paulo 13083-970, Brazil;
| | - Mira Syahfriena Amir Rawa
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, USA; (H.-W.S.); (N.S.W.); (M.S.A.R.); (G.R.N.)
| | - Grant R. Nickles
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, USA; (H.-W.S.); (N.S.W.); (M.S.A.R.); (G.R.N.)
| | - André Damasio
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), São Paulo 13083-970, Brazil;
| | - Nancy P. Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, USA; (H.-W.S.); (N.S.W.); (M.S.A.R.); (G.R.N.)
- Department of Plant Pathology, University of Wisconsin, Madison, WI 53706, USA
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5
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Matsuda K, Maruyama H, Imachi K, Ikeda H, Wakimoto T. Actinobacterial chalkophores: the biosynthesis of hazimycins. J Antibiot (Tokyo) 2024; 77:228-237. [PMID: 38378905 DOI: 10.1038/s41429-024-00706-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Revised: 01/18/2024] [Accepted: 01/22/2024] [Indexed: 02/22/2024]
Abstract
Copper is a transition metal element with significant effects on the morphological development and secondary metabolism of actinobacteria. In some microorganisms, copper-binding natural products are employed to modulate copper homeostasis, although their significance in actinobacteria remains largely unknown. Here, we identified the biosynthetic genes of the diisocyanide natural product hazimycin in Kitasatospora purpeofusca HV058, through gene knock-out and heterologous expression. Biochemical analyses revealed that hazimycin A specifically binds to copper, which diminishes its antimicrobial activity. The presence of a set of putative importer/exporter genes surrounding the biosynthetic genes suggested that hazimycin is a chalkophore that modulates the intracellular copper level. A bioinformatic survey of homologous gene cassettes, as well as the identification of two previously unknown hazimycin-producing Streptomyces strains, indicated that the isocyanide-based mechanism of copper homeostasis is prevalent in actinobacteria.
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Affiliation(s)
- Kenichi Matsuda
- Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12, Nishi 6, Kita-ku, Sapporo, 060-0812, Japan.
| | - Hiroto Maruyama
- Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12, Nishi 6, Kita-ku, Sapporo, 060-0812, Japan
| | - Kumiko Imachi
- Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12, Nishi 6, Kita-ku, Sapporo, 060-0812, Japan
| | - Haruo Ikeda
- Technology Research Association for Next generation natural products chemistry, 2-4-7 Aomi, Koto-ku, Tokyo, 135-0064, Japan
| | - Toshiyuki Wakimoto
- Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12, Nishi 6, Kita-ku, Sapporo, 060-0812, Japan.
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6
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Smith N, Dasgupta M, Wych DC, Dolamore C, Sierra RG, Lisova S, Marchany-Rivera D, Cohen AE, Boutet S, Hunter MS, Kupitz C, Poitevin F, Moss FR, Mittan-Moreau DW, Brewster AS, Sauter NK, Young ID, Wolff AM, Tiwari VK, Kumar N, Berkowitz DB, Hadt RG, Thompson MC, Follmer AH, Wall ME, Wilson MA. Changes in an enzyme ensemble during catalysis observed by high-resolution XFEL crystallography. SCIENCE ADVANCES 2024; 10:eadk7201. [PMID: 38536910 PMCID: PMC10971408 DOI: 10.1126/sciadv.adk7201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 02/21/2024] [Indexed: 04/01/2024]
Abstract
Enzymes populate ensembles of structures necessary for catalysis that are difficult to experimentally characterize. We use time-resolved mix-and-inject serial crystallography at an x-ray free electron laser to observe catalysis in a designed mutant isocyanide hydratase (ICH) enzyme that enhances sampling of important minor conformations. The active site exists in a mixture of conformations, and formation of the thioimidate intermediate selects for catalytically competent substates. The influence of cysteine ionization on the ICH ensemble is validated by determining structures of the enzyme at multiple pH values. Large molecular dynamics simulations in crystallo and time-resolved electron density maps show that Asp17 ionizes during catalysis and causes conformational changes that propagate across the dimer, permitting water to enter the active site for intermediate hydrolysis. ICH exhibits a tight coupling between ionization of active site residues and catalysis-activated protein motions, exemplifying a mechanism of electrostatic control of enzyme dynamics.
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Affiliation(s)
- Nathan Smith
- Department of Biochemistry and Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Medhanjali Dasgupta
- Department of Biochemistry and Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - David C. Wych
- Computer, Computational, and Statistical Sciences Division, Los Alamos National Laboratory, Los Alamos, NM 875405, USA
- Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Cole Dolamore
- Department of Biochemistry and Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Raymond G. Sierra
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA
| | - Stella Lisova
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA
| | - Darya Marchany-Rivera
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA
| | - Aina E. Cohen
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA
| | - Sébastien Boutet
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA
| | - Mark S. Hunter
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA
| | - Christopher Kupitz
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA
| | - Frédéric Poitevin
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA
| | - Frank R. Moss
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA
| | - David W. Mittan-Moreau
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Aaron S. Brewster
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Nicholas K. Sauter
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Iris D. Young
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Alexander M. Wolff
- Department of Chemistry and Biochemistry, University of California, Merced, CA 95340, USA
| | - Virendra K. Tiwari
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Nivesh Kumar
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - David B. Berkowitz
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Ryan G. Hadt
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Michael C. Thompson
- Department of Chemistry and Biochemistry, University of California, Merced, CA 95340, USA
| | - Alec H. Follmer
- Department of Chemistry, University of California-Irvine, Irvine, CA 92697, USA
| | - Michael E. Wall
- Computer, Computational, and Statistical Sciences Division, Los Alamos National Laboratory, Los Alamos, NM 875405, USA
| | - Mark A. Wilson
- Department of Biochemistry and Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
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7
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Larghi EL, Bracca ABJ, Simonetti SO, Kaufman TS. Recent developments in the total synthesis of natural products using the Ugi multicomponent reactions as the key strategy. Org Biomol Chem 2024; 22:429-465. [PMID: 38126459 DOI: 10.1039/d3ob01837g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2023]
Abstract
The total syntheses of selected natural products using different versions of the Ugi multicomponent reaction is reviewed on a case-by-case basis. The revision covers the period 2008-2023 and includes detailed descriptions of the synthetic sequences, the use of state-of-the-art chemical reagents and strategies, as well as the advantages and limitations of the transformation and some remedial solutions. Relevant data on the isolation and bioactivity of the different natural targets are also briefly provided. The examples clearly evidence the strategic importance of this transformation and its key role in the modern natural products synthetic chemistry toolbox. This methodology proved to be a valuable means for easily building molecular complexity and efficiently delivering step-economic syntheses even of intricate structures, with a promising future.
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Affiliation(s)
- Enrique L Larghi
- Instituto de Química Rosario (IQUIR, CONICET-UNR) and Facultad de Ciencias Bioquímicas y Farmacéuticas - Universidad Nacional de Rosario, Suipacha 531 (2000), Rosario, Argentina.
| | - Andrea B J Bracca
- Instituto de Química Rosario (IQUIR, CONICET-UNR) and Facultad de Ciencias Bioquímicas y Farmacéuticas - Universidad Nacional de Rosario, Suipacha 531 (2000), Rosario, Argentina.
| | - Sebastián O Simonetti
- Instituto de Química Rosario (IQUIR, CONICET-UNR) and Facultad de Ciencias Bioquímicas y Farmacéuticas - Universidad Nacional de Rosario, Suipacha 531 (2000), Rosario, Argentina.
| | - Teodoro S Kaufman
- Instituto de Química Rosario (IQUIR, CONICET-UNR) and Facultad de Ciencias Bioquímicas y Farmacéuticas - Universidad Nacional de Rosario, Suipacha 531 (2000), Rosario, Argentina.
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8
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Smith N, Dasgupta M, Wych DC, Dolamore C, Sierra RG, Lisova S, Marchany-Rivera D, Cohen AE, Boutet S, Hunter MS, Kupitz C, Poitevin F, Moss FR, Brewster AS, Sauter NK, Young ID, Wolff AM, Tiwari VK, Kumar N, Berkowitz DB, Hadt RG, Thompson MC, Follmer AH, Wall ME, Wilson MA. Changes in an Enzyme Ensemble During Catalysis Observed by High Resolution XFEL Crystallography. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.15.553460. [PMID: 37645800 PMCID: PMC10462001 DOI: 10.1101/2023.08.15.553460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Enzymes populate ensembles of structures with intrinsically different catalytic proficiencies that are difficult to experimentally characterize. We use time-resolved mix-and-inject serial crystallography (MISC) at an X-ray free electron laser (XFEL) to observe catalysis in a designed mutant (G150T) isocyanide hydratase (ICH) enzyme that enhances sampling of important minor conformations. The active site exists in a mixture of conformations and formation of the thioimidate catalytic intermediate selects for catalytically competent substates. A prior proposal for active site cysteine charge-coupled conformational changes in ICH is validated by determining structures of the enzyme over a range of pH values. A combination of large molecular dynamics simulations of the enzyme in crystallo and time-resolved electron density maps shows that ionization of the general acid Asp17 during catalysis causes additional conformational changes that propagate across the dimer interface, connecting the two active sites. These ionization-linked changes in the ICH conformational ensemble permit water to enter the active site in a location that is poised for intermediate hydrolysis. ICH exhibits a tight coupling between ionization of active site residues and catalysis-activated protein motions, exemplifying a mechanism of electrostatic control of enzyme dynamics.
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Affiliation(s)
- Nathan Smith
- Department of Biochemistry and Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE, 68588
| | - Medhanjali Dasgupta
- Department of Biochemistry and Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE, 68588
| | - David C. Wych
- Computer, Computational, and Statistical Sciences Division, Los Alamos National Laboratory, Los Alamos, NM 875405
- Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, NM 87545
| | - Cole Dolamore
- Department of Biochemistry and Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE, 68588
| | - Raymond G. Sierra
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025
| | - Stella Lisova
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025
| | - Darya Marchany-Rivera
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025
| | - Aina E. Cohen
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025
| | - Sébastien Boutet
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025
| | - Mark S. Hunter
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025
| | - Christopher Kupitz
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025
| | - Frédéric Poitevin
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025
| | - Frank R. Moss
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025
| | - Aaron S. Brewster
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - Nicholas K. Sauter
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - Iris D. Young
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - Alexander M. Wolff
- Department of Chemistry and Biochemistry, University of California, Merced, CA, 93540
| | - Virendra K. Tiwari
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE, 68588
| | - Nivesh Kumar
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE, 68588
| | - David B. Berkowitz
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE, 68588
| | - Ryan G. Hadt
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA USA
| | - Michael C. Thompson
- Department of Chemistry and Biochemistry, University of California, Merced, CA, 93540
| | - Alec H. Follmer
- Department of Chemistry, University of California-Irvine, Irvine, CA 92697
| | - Michael E. Wall
- Computer, Computational, and Statistical Sciences Division, Los Alamos National Laboratory, Los Alamos, NM 875405
| | - Mark A. Wilson
- Department of Biochemistry and Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE, 68588
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9
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Nickles GR, Oestereicher B, Keller NP, Drott M. Mining for a new class of fungal natural products: the evolution, diversity, and distribution of isocyanide synthase biosynthetic gene clusters. Nucleic Acids Res 2023; 51:7220-7235. [PMID: 37427794 PMCID: PMC10415135 DOI: 10.1093/nar/gkad573] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 06/16/2023] [Accepted: 07/06/2023] [Indexed: 07/11/2023] Open
Abstract
The products of non-canonical isocyanide synthase (ICS) biosynthetic gene clusters (BGCs) mediate pathogenesis, microbial competition, and metal-homeostasis through metal-associated chemistry. We sought to enable research into this class of compounds by characterizing the biosynthetic potential and evolutionary history of these BGCs across the Fungal Kingdom. We amalgamated a pipeline of tools to predict BGCs based on shared promoter motifs and located 3800 ICS BGCs in 3300 genomes, making ICS BGCs the fifth largest class of specialized metabolites compared to canonical classes found by antiSMASH. ICS BGCs are not evenly distributed across fungi, with evidence of gene-family expansions in several Ascomycete families. We show that the ICS dit1/2 gene cluster family (GCF), which was prior only studied in yeast, is present in ∼30% of all Ascomycetes. The dit variety ICS exhibits greater similarity to bacterial ICS than other fungal ICS, suggesting a potential convergence of the ICS backbone domain. The evolutionary origins of the dit GCF in Ascomycota are ancient and these genes are diversifying in some lineages. Our results create a roadmap for future research into ICS BGCs. We developed a website (https://isocyanides.fungi.wisc.edu/) that facilitates the exploration and downloading of all identified fungal ICS BGCs and GCFs.
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Affiliation(s)
- Grant R Nickles
- Department of Medical Microbiology and Immunology, University of Wisconsin—Madison, Madison, WI 53706, USA
| | | | - Nancy P Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin—Madison, Madison, WI 53706, USA
- Department of Plant Pathology, University of Wisconsin—Madison, Madison, WI 53706, USA
| | - Milton T Drott
- USDA-ARS Cereal Disease Lab (CDL), St. Paul, MN 55108, USA
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10
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Zhgun AA. Fungal BGCs for Production of Secondary Metabolites: Main Types, Central Roles in Strain Improvement, and Regulation According to the Piano Principle. Int J Mol Sci 2023; 24:11184. [PMID: 37446362 PMCID: PMC10342363 DOI: 10.3390/ijms241311184] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 06/28/2023] [Accepted: 07/03/2023] [Indexed: 07/15/2023] Open
Abstract
Filamentous fungi are one of the most important producers of secondary metabolites. Some of them can have a toxic effect on the human body, leading to diseases. On the other hand, they are widely used as pharmaceutically significant drugs, such as antibiotics, statins, and immunosuppressants. A single fungus species in response to various signals can produce 100 or more secondary metabolites. Such signaling is possible due to the coordinated regulation of several dozen biosynthetic gene clusters (BGCs), which are mosaically localized in different regions of fungal chromosomes. Their regulation includes several levels, from pathway-specific regulators, whose genes are localized inside BGCs, to global regulators of the cell (taking into account changes in pH, carbon consumption, etc.) and global regulators of secondary metabolism (affecting epigenetic changes driven by velvet family proteins, LaeA, etc.). In addition, various low-molecular-weight substances can have a mediating effect on such regulatory processes. This review is devoted to a critical analysis of the available data on the "turning on" and "off" of the biosynthesis of secondary metabolites in response to signals in filamentous fungi. To describe the ongoing processes, the model of "piano regulation" is proposed, whereby pressing a certain key (signal) leads to the extraction of a certain sound from the "musical instrument of the fungus cell", which is expressed in the production of a specific secondary metabolite.
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Affiliation(s)
- Alexander A Zhgun
- Group of Fungal Genetic Engineering, Federal Research Center "Fundamentals of Biotechnology", Russian Academy of Sciences, Leninsky Prosp. 33-2, 119071 Moscow, Russia
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11
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Patil RH, Luptáková D, Havlíček V. Infection metallomics for critical care in the post-COVID era. MASS SPECTROMETRY REVIEWS 2023; 42:1221-1243. [PMID: 34854486 DOI: 10.1002/mas.21755] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 07/15/2021] [Accepted: 07/15/2021] [Indexed: 06/07/2023]
Abstract
Infection metallomics is a mass spectrometry (MS) platform we established based on the central concept that microbial metallophores are specific, sensitive, noninvasive, and promising biomarkers of invasive infectious diseases. Here we review the in vitro, in vivo, and clinical applications of metallophores from historical and functional perspectives, and identify under-studied and emerging application areas with high diagnostic potential for the post-COVID era. MS with isotope data filtering is fundamental to infection metallomics; it has been used to study the interplay between "frenemies" in hosts and to monitor the dynamic response of the microbiome to antibiotic and antimycotic therapies. During infection in critically ill patients, the hostile environment of the host's body activates secondary bacterial, mycobacterial, and fungal metabolism, leading to the production of metallophores that increase the pathogen's chance of survival in the host. MS can reveal the structures, stability, and threshold concentrations of these metal-containing microbial biomarkers of infection in humans and model organisms, and can discriminate invasive disease from benign colonization based on well-defined thresholds distinguishing proliferation from the colonization steady state.
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Affiliation(s)
- Rutuja H Patil
- Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
- Department of Analytical Chemistry, Faculty of Science, Palacký University, Olomouc, Czechia
| | - Dominika Luptáková
- Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
| | - Vladimír Havlíček
- Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
- Department of Analytical Chemistry, Faculty of Science, Palacký University, Olomouc, Czechia
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12
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Nickles GR, Oestereicher B, Keller NP, Drott MT. Mining for a New Class of Fungal Natural Products: The Evolution, Diversity, and Distribution of Isocyanide Synthase Biosynthetic Gene Clusters. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.17.537281. [PMID: 37131656 PMCID: PMC10153163 DOI: 10.1101/2023.04.17.537281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The products of non-canonical isocyanide synthase (ICS) biosynthetic gene clusters (BGCs) have notable bioactivities that mediate pathogenesis, microbial competition, and metal-homeostasis through metal-associated chemistry. We sought to enable research into this class of compounds by characterizing the biosynthetic potential and evolutionary history of these BGCs across the Fungal Kingdom. We developed the first genome-mining pipeline to identify ICS BGCs, locating 3,800 ICS BGCs in 3,300 genomes. Genes in these clusters share promoter motifs and are maintained in contiguous groupings by natural selection. ICS BGCs are not evenly distributed across fungi, with evidence of gene-family expansions in several Ascomycete families. We show that the ICS dit1 / 2 gene cluster family (GCF), which was thought to only exist in yeast, is present in ∼30% of all Ascomycetes, including many filamentous fungi. The evolutionary history of the dit GCF is marked by deep divergences and phylogenetic incompatibilities that raise questions about convergent evolution and suggest selection or horizontal gene transfers have shaped the evolution of this cluster in some yeast and dimorphic fungi. Our results create a roadmap for future research into ICS BGCs. We developed a website ( www.isocyanides.fungi.wisc.edu ) that facilitates the exploration, filtering, and downloading of all identified fungal ICS BGCs and GCFs.
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Affiliation(s)
- Grant R. Nickles
- Department of Medical Microbiology and Immunology, University of Wisconsin—Madison, Madison, WI 53706, USA
| | | | - Nancy P. Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin—Madison, Madison, WI 53706, USA
- Department of Plant Pathology, University of Wisconsin—Madison, Madison, WI 53706, USA
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13
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Yang J, Song Y, Zhou Z, Huang Y, Wang S, Yuan J, Wong NK, Yan Y, Ju J. Sulfoxanthicillin from the deep-sea derived Penicillium sp. SCSIO sof101: an antimicrobial compound against Gram-positive and -negative pathogens. J Antibiot (Tokyo) 2023; 76:113-120. [PMID: 36642755 DOI: 10.1038/s41429-022-00593-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Revised: 11/22/2022] [Accepted: 12/03/2022] [Indexed: 01/17/2023]
Abstract
Natural products along with their analogs have been intensively explored for their antimicrobial potential against 'ESKAPE' pathogens. Herein, we report a new natural product with strong antibacterial activity, sulfoxanthocillin (1), along with its decomposed product peniformamide (2), and the known compound xanthocillin X (3) from the deep-sea derived Penicillium sp. SCSIO sof101. The structures of compounds 1 and 2 were determined by extensive spectroscopic analysis. Compound 1 showed significant activity against series pathogens with MIC values ranging 0.06-8.0 μg mL-1. As an artificial unnatural product during the isolation process, compound 2 had lower antimicrobial activity than that of compound 1, which could be attributed to a change in structural modification from an isonitrile group in compound 1 to a formamide group in compound 2. In terms of cytotoxicity, 1 showed relatively low cytotoxicity against human tumor cell lines compared with xanthocillin X (3), suggesting that the sulfate group present in 1 should be a determinant of cytotoxic activities. Overall, sulfoxanthocillin (1) merits further attention as a potential lead compound for anti-infective interventions against Gram-negative and Gram-positive bacterial pathogens.
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Affiliation(s)
- Jiafan Yang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou, 510301, China
- College of Oceanology, University of Chinese Academy of Sciences, Qingdao, 266400, China
| | - Yongxiang Song
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou, 510301, China.
- College of Oceanology, University of Chinese Academy of Sciences, Qingdao, 266400, China.
| | - Zhenbin Zhou
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou, 510301, China
- College of Oceanology, University of Chinese Academy of Sciences, Qingdao, 266400, China
| | - Yun Huang
- School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Songtao Wang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou, 510301, China
- College of Oceanology, University of Chinese Academy of Sciences, Qingdao, 266400, China
| | - Jie Yuan
- Key Laboratory of Tropical Disease Control, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China
| | - Nai-Kei Wong
- Department of Pharmacology, Shantou University Medical College, Shantou, Guangdong, 515041, China
| | - Yan Yan
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou, 510301, China
- College of Oceanology, University of Chinese Academy of Sciences, Qingdao, 266400, China
| | - Jianhua Ju
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou, 510301, China.
- College of Oceanology, University of Chinese Academy of Sciences, Qingdao, 266400, China.
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14
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Aguiar M, Orasch T, Shadkchan Y, Caballero P, Pfister J, Sastré-Velásquez LE, Gsaller F, Decristoforo C, Osherov N, Haas H. Uptake of the Siderophore Triacetylfusarinine C, but Not Fusarinine C, Is Crucial for Virulence of Aspergillus fumigatus. mBio 2022; 13:e0219222. [PMID: 36125294 PMCID: PMC9600649 DOI: 10.1128/mbio.02192-22] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 09/02/2022] [Indexed: 11/20/2022] Open
Abstract
Siderophores play an important role in fungal virulence, serving as trackers for in vivo imaging and as biomarkers of fungal infections. However, siderophore uptake is only partially characterized. As the major cause of aspergillosis, Aspergillus fumigatus is one of the most common airborne fungal pathogens of humans. Here, we demonstrate that this mold species mediates the uptake of iron chelated by the secreted siderophores triacetylfusarinine C (TAFC) and fusarinine C by the major facilitator-type transporters MirB and MirD, respectively. In a murine aspergillosis model, MirB but not MirD was found to be crucial for virulence, indicating that TAFC-mediated uptake plays a dominant role during infection. In the absence of MirB, TAFC becomes inhibitory by decreasing iron availability because the mutant is not able to recognize iron that is chelated by TAFC. MirB-mediated transport was found to tolerate the conjugation of fluorescein isothiocyanate to triacetylfusarinine C, which might aid in the development of siderophore-based antifungals in a Trojan horse approach, particularly as the role of MirB in pathogenicity restrains its mutational inactivation. Taken together, this study identified the first eukaryotic siderophore transporter that is crucial for virulence and elucidated its translational potential as well as its evolutionary conservation. IMPORTANCE Aspergillus fumigatus is responsible for thousands of cases of invasive fungal disease annually. For iron uptake, A. fumigatus secretes so-called siderophores, which are taken up after the binding of environmental iron. Moreover, A. fumigatus can utilize siderophore types that are produced by other fungi or bacteria. Fungal siderophores raised considerable interest due to their role in virulence and their potential for the diagnosis and treatment of fungal infections. Here, we demonstrate that the siderophore transporter MirB is crucial for the virulence of A. fumigatus, which reveals that its substrate, triacetylfusarinine C, is the most important siderophore during infection. We found that in the absence of MirB, TAFC becomes inhibitory by decreasing the availability of environmental iron and that MirB-mediated transport tolerates the derivatization of its substrate, which might aid in the development of siderophore-based antifungals. This study significantly improved the understanding of fungal iron homeostasis and the role of siderophores in interactions with the host.
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Affiliation(s)
- Mario Aguiar
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Thomas Orasch
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Yana Shadkchan
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine Ramat-Aviv, Tel Aviv, Israel
| | - Patricia Caballero
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Joachim Pfister
- Department of Nuclear Medicine, Medical University Innsbruck, Innsbruck, Austria
| | | | - Fabio Gsaller
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Clemens Decristoforo
- Department of Nuclear Medicine, Medical University Innsbruck, Innsbruck, Austria
| | - Nir Osherov
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine Ramat-Aviv, Tel Aviv, Israel
| | - Hubertus Haas
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
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15
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Schüller A, Studt-Reinhold L, Strauss J. How to Completely Squeeze a Fungus-Advanced Genome Mining Tools for Novel Bioactive Substances. Pharmaceutics 2022; 14:1837. [PMID: 36145585 PMCID: PMC9505985 DOI: 10.3390/pharmaceutics14091837] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 08/23/2022] [Accepted: 08/29/2022] [Indexed: 11/17/2022] Open
Abstract
Fungal species have the capability of producing an overwhelming diversity of bioactive substances that can have beneficial but also detrimental effects on human health. These so-called secondary metabolites naturally serve as antimicrobial "weapon systems", signaling molecules or developmental effectors for fungi and hence are produced only under very specific environmental conditions or stages in their life cycle. However, as these complex conditions are difficult or even impossible to mimic in laboratory settings, only a small fraction of the true chemical diversity of fungi is known so far. This also implies that a large space for potentially new pharmaceuticals remains unexplored. We here present an overview on current developments in advanced methods that can be used to explore this chemical space. We focus on genetic and genomic methods, how to detect genes that harbor the blueprints for the production of these compounds (i.e., biosynthetic gene clusters, BGCs), and ways to activate these silent chromosomal regions. We provide an in-depth view of the chromatin-level regulation of BGCs and of the potential to use the CRISPR/Cas technology as an activation tool.
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Affiliation(s)
| | | | - Joseph Strauss
- Institute of Microbial Genetics, Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences Vienna, A-3430 Tulln/Donau, Austria
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16
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Won TH, Bok JW, Nadig N, Venkatesh N, Nickles G, Greco C, Lim FY, González JB, Turgeon BG, Keller NP, Schroeder FC. Copper starvation induces antimicrobial isocyanide integrated into two distinct biosynthetic pathways in fungi. Nat Commun 2022; 13:4828. [PMID: 35973982 PMCID: PMC9381783 DOI: 10.1038/s41467-022-32394-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 07/29/2022] [Indexed: 01/26/2023] Open
Abstract
The genomes of many filamentous fungi, such as Aspergillus spp., include diverse biosynthetic gene clusters of unknown function. We previously showed that low copper levels upregulate a gene cluster that includes crmA, encoding a putative isocyanide synthase. Here we show, using untargeted comparative metabolomics, that CrmA generates a valine-derived isocyanide that contributes to two distinct biosynthetic pathways under copper-limiting conditions. Reaction of the isocyanide with an ergot alkaloid precursor results in carbon-carbon bond formation analogous to Strecker amino-acid synthesis, producing a group of alkaloids we term fumivalines. In addition, valine isocyanide contributes to biosynthesis of a family of acylated sugar alcohols, the fumicicolins, which are related to brassicicolin A, a known isocyanide from Alternaria brassicicola. CrmA homologs are found in a wide range of pathogenic and non-pathogenic fungi, some of which produce fumicicolin and fumivaline. Extracts from A. fumigatus wild type (but not crmA-deleted strains), grown under copper starvation, inhibit growth of diverse bacteria and fungi, and synthetic valine isocyanide shows antibacterial activity. CrmA thus contributes to two biosynthetic pathways downstream of trace-metal sensing.
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Affiliation(s)
- Tae Hyung Won
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA
| | - Jin Woo Bok
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, USA
| | - Nischala Nadig
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, USA
| | - Nandhitha Venkatesh
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI, USA
| | - Grant Nickles
- Department of Cellular and Molecular Biology, University of Wisconsin-Madison, Madison, WI, USA
| | - Claudio Greco
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, USA
- Department of Molecular Microbiology, John Innes Centre, Norwich, NR4 7UH, United Kingdom
| | - Fang Yun Lim
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, USA
- Department of Chemistry, University of Washington, Seattle, WA, USA
| | - Jennifer B González
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, NY, USA
- 104 Peckham Hall, Nazareth College, 4245 East Avenue, Rochester, NY, USA
| | - B Gillian Turgeon
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, NY, USA
| | - Nancy P Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, USA.
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, USA.
| | - Frank C Schroeder
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA.
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17
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Del Rio Flores A, Kastner DW, Du Y, Narayanamoorthy M, Shen Y, Cai W, Vennelakanti V, Zill NA, Dell LB, Zhai R, Kulik HJ, Zhang W. Probing the Mechanism of Isonitrile Formation by a Non-Heme Iron(II)-Dependent Oxidase/Decarboxylase. J Am Chem Soc 2022; 144:5893-5901. [PMID: 35254829 PMCID: PMC8986608 DOI: 10.1021/jacs.1c12891] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The isonitrile moiety is an electron-rich functionality that decorates various bioactive natural products isolated from diverse kingdoms of life. Isonitrile biosynthesis was restricted for over a decade to isonitrile synthases, a family of enzymes catalyzing a condensation reaction between l-Trp/l-Tyr and ribulose-5-phosphate. The discovery of ScoE, a non-heme iron(II) and α-ketoglutarate-dependent dioxygenase, demonstrated an alternative pathway employed by nature for isonitrile installation. Biochemical, crystallographic, and computational investigations of ScoE have previously been reported, yet the isonitrile formation mechanism remains obscure. In the present work, we employed in vitro biochemistry, chemical synthesis, spectroscopy techniques, and computational simulations that enabled us to propose a plausible molecular mechanism for isonitrile formation. Our findings demonstrate that the ScoE reaction initiates with C5 hydroxylation of (R)-3-((carboxymethyl)amino)butanoic acid to generate 1, which undergoes dehydration, presumably mediated by Tyr96 to synthesize 2 in a trans configuration. (R)-3-isocyanobutanoic acid is finally generated through radical-based decarboxylation of 2, instead of the common hydroxylation pathway employed by this enzyme superfamily.
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Affiliation(s)
- Antonio Del Rio Flores
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California, United States 94720
| | - David W. Kastner
- Department of Bioengineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States 02139
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States 02139
| | - Yongle Du
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California, United States 94720
| | - Maanasa Narayanamoorthy
- Department of Chemistry, University of California, Berkeley, California, United States 94720
| | - Yuanbo Shen
- Department of Chemistry, University of California, Berkeley, California, United States 94720
| | - Wenlong Cai
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California, United States 94720
| | - Vyshnavi Vennelakanti
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States 02139
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States 02139
| | - Nicholas A. Zill
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California, United States 94720
| | - Luisa B. Dell
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California, United States 94720
| | - Rui Zhai
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California, United States 94720
| | - Heather J. Kulik
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States 02139
| | - Wenjun Zhang
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California, United States 94720
- Chan Zuckerberg Biohub, San Francisco, California, United States 94158
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18
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Miller B, Schmidt EW, Concepcion GP, Haygood MG. Halogenated Metal-Binding Compounds from Shipworm Symbionts. JOURNAL OF NATURAL PRODUCTS 2022; 85:479-484. [PMID: 35196451 PMCID: PMC8961882 DOI: 10.1021/acs.jnatprod.1c01049] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Indexed: 06/02/2023]
Abstract
Bacteria use small molecules to impose strict regulation over the acquisition, uptake, and sequestration of transition metal ions. Low-abundance nutrient metals, such as Fe(III), need to be scavenged from the environment by high-affinity chelating molecules called siderophores. Conversely, metal ions that become toxic at high concentrations need to be sequestered and detoxified. Often, bacteria produce a suite of compounds that bind various metal ions at different affinities in order to maintain homeostasis. Turnerbactin, a triscatecholate siderophore isolated from the intracellular shipworm symbiont Teredinibacter turnerae T7901, is responsible for iron regulation and uptake. Herein, another series of compounds are described that complex with iron, copper, and molybdenum in solution. Teredinibactins belong to a class of metal-binding molecules that utilize a phenolate-thiazoline moiety in the coordination of metal ions. In contrast to other compounds in this class, such as yersiniabactin, the phenyl ring is decorated with a 2,4-dihydroxy-3-halo substitution pattern. UV-vis absorption spectroscopy based titration experiments with CuCl2 show the formation of an intermediate complex at substoichiometric concentrations and conversion to a copper-bound complex at 1:1 molar equiv.
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Affiliation(s)
- Bailey
W. Miller
- Department
of Medicinal Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
| | - Eric W. Schmidt
- Department
of Medicinal Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
| | - Gisela P. Concepcion
- The
Marine Science Institute, University of
the Philippines, Diliman, Quezon
City 1101, Philippines
| | - Margo G. Haygood
- Department
of Medicinal Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
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19
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Traynor AM, Owens RA, Coughlin CM, Holton MC, Jones GW, Calera JA, Doyle S. At the metal-metabolite interface in Aspergillus fumigatus: towards untangling the intersecting roles of zinc and gliotoxin. MICROBIOLOGY (READING, ENGLAND) 2021; 167. [PMID: 34738889 PMCID: PMC8743625 DOI: 10.1099/mic.0.001106] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Cryptic links between apparently unrelated metabolic systems represent potential new drug targets in fungi. Evidence of such a link between zinc and gliotoxin (GT) biosynthesis in Aspergillus fumigatus is emerging. Expression of some genes of the GT biosynthetic gene cluster gli is influenced by the zinc-dependent transcription activator ZafA, zinc may relieve GT-mediated fungal growth inhibition and, surprisingly, GT biosynthesis is influenced by zinc availability. In A. fumigatus, dithiol gliotoxin (DTG), which has zinc-chelating properties, is converted to either GT or bis-dethiobis(methylthio)gliotoxin (BmGT) by oxidoreductase GliT and methyltransferase GtmA, respectively. A double deletion mutant lacking both GliT and GtmA was previously observed to be hypersensitive to exogenous GT exposure. Here we show that compared to wild-type exposure, exogenous GT and the zinc chelator N,N,N',N'-tetrakis(2-pyridinylmethyl)-1,2-ethanediamine (TPEN) inhibit A. fumigatus ΔgliTΔgtmA growth, specifically under zinc-limiting conditions, which can be reversed by zinc addition. While GT biosynthesis is evident in zinc-depleted medium, addition of zinc (1 µM) suppressed GT and activated BmGT production. In addition, secretion of the unferrated siderophore, triacetylfusarinine C (TAFC), was evident by A. fumigatus wild-type (at >5 µM zinc) and ΔgtmA (at >1 µM zinc) in a low-iron medium. TAFC secretion suggests that differential zinc-sensing between both strains may influence fungal Fe3+ requirement. Label-free quantitative proteomic analysis of both strains under equivalent differential zinc conditions revealed protein abundance alterations in accordance with altered metabolomic observations, in addition to increased GliT abundance in ΔgtmA at 5 µM zinc, compared to wild-type, supporting a zinc-sensing deficiency in the mutant strain. The relative abundance of a range of oxidoreductase- and secondary metabolism-related enzymes was also evident in a zinc- and strain-dependent manner. Overall, we elaborate new linkages between zinc availability, natural product biosynthesis and oxidative stress homeostasis in A. fumigatus.
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Affiliation(s)
- Aimee M Traynor
- Department of Biology, Maynooth University, Maynooth, Co. Kildare, Ireland
| | - Rebecca A Owens
- Department of Biology, Maynooth University, Maynooth, Co. Kildare, Ireland
| | - Claudia M Coughlin
- Department of Biology, Maynooth University, Maynooth, Co. Kildare, Ireland
| | - Maeve C Holton
- Department of Biology, Maynooth University, Maynooth, Co. Kildare, Ireland
| | - Gary W Jones
- Centre for Biomedical Science Research, School of Clinical and Applied Sciences, Leeds Beckett University, Leeds, UK
| | - José A Calera
- Instituto de Biología Funcional y Genómica (IBFG-CSIC), Universidad de Salamanca, Salamanca, Spain
- Departamento de Microbiología y Genética, Universidad de Salamanca, Salamanca, Spain
| | - Sean Doyle
- Department of Biology, Maynooth University, Maynooth, Co. Kildare, Ireland
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20
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Vignolle GA, Schaffer D, Zehetner L, Mach RL, Mach-Aigner AR, Derntl C. FunOrder: A robust and semi-automated method for the identification of essential biosynthetic genes through computational molecular co-evolution. PLoS Comput Biol 2021; 17:e1009372. [PMID: 34570757 PMCID: PMC8476034 DOI: 10.1371/journal.pcbi.1009372] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 08/23/2021] [Indexed: 11/24/2022] Open
Abstract
Secondary metabolites (SMs) are a vast group of compounds with different structures and properties that have been utilized as drugs, food additives, dyes, and as monomers for novel plastics. In many cases, the biosynthesis of SMs is catalysed by enzymes whose corresponding genes are co-localized in the genome in biosynthetic gene clusters (BGCs). Notably, BGCs may contain so-called gap genes, that are not involved in the biosynthesis of the SM. Current genome mining tools can identify BGCs, but they have problems with distinguishing essential genes from gap genes. This can and must be done by expensive, laborious, and time-consuming comparative genomic approaches or transcriptome analyses. In this study, we developed a method that allows semi-automated identification of essential genes in a BGC based on co-evolution analysis. To this end, the protein sequences of a BGC are blasted against a suitable proteome database. For each protein, a phylogenetic tree is created. The trees are compared by treeKO to detect co-evolution. The results of this comparison are visualized in different output formats, which are compared visually. Our results suggest that co-evolution is commonly occurring within BGCs, albeit not all, and that especially those genes that encode for enzymes of the biosynthetic pathway are co-evolutionary linked and can be identified with FunOrder. In light of the growing number of genomic data available, this will contribute to the studies of BGCs in native hosts and facilitate heterologous expression in other organisms with the aim of the discovery of novel SMs. The discovery and description of novel fungal secondary metabolites promises novel antibiotics, pharmaceuticals, and other useful compounds. A way to identify novel secondary metabolites is to express the corresponding genes in a suitable expression host. Consequently, a detailed knowledge or an accurate prediction of these genes is necessary. In fungi, the genes are co-localized in so-called biosynthetic gene clusters. Notably, the clusters may also contain genes that are not necessary for the biosynthesis of the secondary metabolites, so-called gap genes. We developed a method to detect co-evolved genes within the clusters and demonstrated that essential genes are co-evolving and can thus be differentiated from the gap genes. This adds an additional layer of information, which can support researchers with their decisions on which genes to study and express for the discovery of novel secondary metabolites.
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Affiliation(s)
- Gabriel A. Vignolle
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Vienna, Austria
| | - Denise Schaffer
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Vienna, Austria
| | - Leopold Zehetner
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Vienna, Austria
| | - Robert L. Mach
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Vienna, Austria
| | - Astrid R. Mach-Aigner
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Vienna, Austria
| | - Christian Derntl
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Vienna, Austria
- * E-mail:
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21
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Massarotti A, Brunelli F, Aprile S, Giustiniano M, Tron GC. Medicinal Chemistry of Isocyanides. Chem Rev 2021; 121:10742-10788. [PMID: 34197077 DOI: 10.1021/acs.chemrev.1c00143] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In eons of evolution, isocyanides carved out a niche in the ecological systems probably thanks to their metal coordinating properties. In 1859 the first isocyanide was synthesized by humans and in 1950 the first natural isocyanide was discovered. Now, at the beginning of XXI century, hundreds of isocyanides have been isolated both in prokaryotes and eukaryotes and thousands have been synthesized in the laboratory. For some of them their ecological role is known, and their potent biological activity as antibacterial, antifungal, antimalarial, antifouling, and antitumoral compounds has been described. Notwithstanding, the isocyanides have not gained a good reputation among medicinal chemists who have erroneously considered them either too reactive or metabolically unstable, and this has restricted their main use to technical applications as ligands in coordination chemistry. The aim of this review is therefore to show the richness in biological activity of the isocyanide-containing molecules, to support the idea of using the isocyanide functional group as an unconventional pharmacophore especially useful as a metal coordinating warhead. The unhidden hope is to convince the skeptical medicinal chemists of the isocyanide potential in many areas of drug discovery and considering them in the design of future drugs.
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Affiliation(s)
- Alberto Massarotti
- Dipartimento di Scienze del Farmaco, Università del Piemonte Orientale, Largo Donegani 2, 28100 Novara, Italy
| | - Francesca Brunelli
- Dipartimento di Scienze del Farmaco, Università del Piemonte Orientale, Largo Donegani 2, 28100 Novara, Italy
| | - Silvio Aprile
- Dipartimento di Scienze del Farmaco, Università del Piemonte Orientale, Largo Donegani 2, 28100 Novara, Italy
| | - Mariateresa Giustiniano
- Dipartimento di Farmacia, Università degli Studi di Napoli "Federico II", Via D. Montesano 49, 80131 Napoli, Italy
| | - Gian Cesare Tron
- Dipartimento di Scienze del Farmaco, Università del Piemonte Orientale, Largo Donegani 2, 28100 Novara, Italy
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22
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Wang W, Yu Y, Keller NP, Wang P. Presence, Mode of Action, and Application of Pathway Specific Transcription Factors in Aspergillus Biosynthetic Gene Clusters. Int J Mol Sci 2021; 22:ijms22168709. [PMID: 34445420 PMCID: PMC8395729 DOI: 10.3390/ijms22168709] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 08/10/2021] [Accepted: 08/10/2021] [Indexed: 01/21/2023] Open
Abstract
Fungal secondary metabolites are renowned toxins as well as valuable sources of antibiotics, cholesterol-lowering drugs, and immunosuppressants; hence, great efforts were levied to understand how these compounds are genetically regulated. The genes encoding for the enzymes required for synthesizing secondary metabolites are arranged in biosynthetic gene clusters (BGCs). Often, BGCs contain a pathway specific transcription factor (PSTF), a valuable tool in shutting down or turning up production of the BGC product. In this review, we present an in-depth view of PSTFs by examining over 40 characterized BGCs in the well-studied fungal species Aspergillus nidulans and Aspergillus fumigatus. Herein, we find BGC size is a predictor for presence of PSTFs, consider the number and the relative location of PSTF in regard to the cluster(s) regulated, discuss the function and the evolution of PSTFs, and present application strategies for pathway specific activation of cryptic BGCs.
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Affiliation(s)
- Wenjie Wang
- Ocean College, Zhejiang University, Zhoushan 316021, China; (W.W.); (Y.Y.)
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Yuchao Yu
- Ocean College, Zhejiang University, Zhoushan 316021, China; (W.W.); (Y.Y.)
| | - Nancy P. Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI 53706, USA
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA
- Correspondence: (N.P.K.); (P.W.)
| | - Pinmei Wang
- Ocean College, Zhejiang University, Zhoushan 316021, China; (W.W.); (Y.Y.)
- Correspondence: (N.P.K.); (P.W.)
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23
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Dual-purpose isocyanides produced by Aspergillus fumigatus contribute to cellular copper sufficiency and exhibit antimicrobial activity. Proc Natl Acad Sci U S A 2021; 118:2015224118. [PMID: 33593906 DOI: 10.1073/pnas.2015224118] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The maintenance of sufficient but nontoxic pools of metal micronutrients is accomplished through diverse homeostasis mechanisms in fungi. Siderophores play a well established role for iron homeostasis; however, no copper-binding analogs have been found in fungi. Here we demonstrate that, in Aspergillus fumigatus, xanthocillin and other isocyanides derived from the xan biosynthetic gene cluster (BGC) bind copper, impact cellular copper content, and have significant metal-dependent antimicrobial properties. xan BGC-derived isocyanides are secreted and bind copper as visualized by a chrome azurol S (CAS) assay, and inductively coupled plasma mass spectrometry analysis of A. fumigatus intracellular copper pools demonstrated a role for xan cluster metabolites in the accumulation of copper. A. fumigatus coculture with a variety of human pathogenic fungi and bacteria established copper-dependent antimicrobial properties of xan BGC metabolites, including inhibition of laccase activity. Remediation of xanthocillin-treated Pseudomonas aeruginosa growth by copper supported the copper-chelating properties of xan BGC isocyanide products. The existence of the xan BGC in several filamentous fungi suggests a heretofore unknown role of eukaryotic natural products in copper homeostasis and mediation of interactions with competing microbes.
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24
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Boysen JM, Saeed N, Hillmann F. Natural products in the predatory defence of the filamentous fungal pathogen Aspergillus fumigatus. Beilstein J Org Chem 2021; 17:1814-1827. [PMID: 34394757 PMCID: PMC8336654 DOI: 10.3762/bjoc.17.124] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 07/14/2021] [Indexed: 11/30/2022] Open
Abstract
The kingdom of fungi comprises a large and highly diverse group of organisms that thrive in diverse natural environments. One factor to successfully confront challenges in their natural habitats is the capability to synthesize defensive secondary metabolites. The genetic potential for the production of secondary metabolites in fungi is high and numerous potential secondary metabolite gene clusters have been identified in sequenced fungal genomes. Their production may well be regulated by specific ecological conditions, such as the presence of microbial competitors, symbionts or predators. Here we exemplarily summarize our current knowledge on identified secondary metabolites of the pathogenic fungus Aspergillus fumigatus and their defensive function against (microbial) predators.
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Affiliation(s)
- Jana M Boysen
- Junior Research Group Evolution of Microbial Interactions, Leibniz-Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (HKI), Beutenbergstr. 11a, 07745 Jena, Germany
- Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Nauman Saeed
- Junior Research Group Evolution of Microbial Interactions, Leibniz-Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (HKI), Beutenbergstr. 11a, 07745 Jena, Germany
- Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Falk Hillmann
- Junior Research Group Evolution of Microbial Interactions, Leibniz-Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (HKI), Beutenbergstr. 11a, 07745 Jena, Germany
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25
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Abstract
The fungal kingdom has provided advances in our ability to identify biosynthetic gene clusters (BGCs) and to examine how gene composition of BGCs evolves across species and genera. However, little is known about the evolution of specific BGC regulators that mediate how BGCs produce secondary metabolites (SMs). A bioinformatics search for conservation of the Aspergillus fumigatus xanthocillin BGC revealed an evolutionary trail of xan-like BGCs across Eurotiales species. Although the critical regulatory and enzymatic genes were conserved in Penicillium expansum, overexpression (OE) of the conserved xan BGC transcription factor (TF) gene, PexanC, failed to activate the putative xan BGC transcription or xanthocillin production in P. expansum, in contrast to the role of AfXanC in A. fumigatus. Surprisingly, OE::PexanC was instead found to promote citrinin synthesis in P. expansum via trans induction of the cit pathway-specific TF, ctnA, as determined by cit BGC expression and chemical profiling of ctnA deletion and OE::PexanC single and double mutants. OE::AfxanC results in significant increases of xan gene expression and metabolite synthesis in A. fumigatus but had no effect on either xanthocillin or citrinin production in P. expansum. Bioinformatics and promoter mutation analysis led to the identification of an AfXanC binding site, 5'-AGTCAGCA-3', in promoter regions of the A. fumigatus xan BGC genes. This motif was not in the ctnA promoter, suggesting a different binding site of PeXanC. A compilation of a bioinformatics examination of XanC orthologs and the presence/absence of the 5'-AGTCAGCA-3' binding motif in xan BGCs in multiple Aspergillus and Penicillium spp. supports an evolutionary divergence of XanC regulatory targets that we speculate reflects an exaptation event in the Eurotiales. IMPORTANCE Fungal secondary metabolites (SMs) are an important source of pharmaceuticals on one hand and toxins on the other. Efforts to identify the biosynthetic gene clusters (BGCs) that synthesize SMs have yielded significant insights into how variation in the genes that compose BGCs may impact subsequent metabolite production within and between species. However, the role of regulatory genes in BGC activation is less well understood. Our finding that the bZIP transcription factor XanC, located in the xanthocillin BGC of both Aspergillus fumigatus and Penicillium expansum, has functionally diverged to regulate different BGCs in these two species emphasizes that the diversification of BGC regulatory elements may sometimes occur through exaptation, which is the co-option of a gene that evolved for one function to a novel function. Furthermore, this work suggests that the loss/gain of transcription factor binding site targets may be an important mediator in the evolution of secondary-metabolism regulatory elements.
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26
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Hübner I, Shapiro JA, Hoßmann J, Drechsel J, Hacker SM, Rather PN, Pieper DH, Wuest WM, Sieber SA. Broad Spectrum Antibiotic Xanthocillin X Effectively Kills Acinetobacter baumannii via Dysregulation of Heme Biosynthesis. ACS CENTRAL SCIENCE 2021; 7:488-498. [PMID: 33791430 PMCID: PMC8006170 DOI: 10.1021/acscentsci.0c01621] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Indexed: 05/19/2023]
Abstract
Isonitrile natural products exhibit promising antibacterial activities. However, their mechanism of action (MoA) remains largely unknown. Based on the nanomolar potency of xanthocillin X (Xan) against diverse difficult-to-treat Gram-negative bacteria, including the critical priority pathogen Acinetobacter baumannii, we performed in-depth studies to decipher its MoA. While neither metal binding nor cellular protein targets were detected as relevant for Xan's antibiotic effects, sequencing of resistant strains revealed a conserved mutation in the heme biosynthesis enzyme porphobilinogen synthase (PbgS). This mutation caused impaired enzymatic efficiency indicative of reduced heme production. This discovery led to the validation of an untapped mechanism, by which direct heme sequestration of Xan prevents its binding into cognate enzyme pockets resulting in uncontrolled cofactor biosynthesis, accumulation of porphyrins, and corresponding stress with deleterious effects for bacterial viability. Thus, Xan represents a promising antibiotic displaying activity even against multidrug resistant strains, while exhibiting low toxicity to human cells.
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Affiliation(s)
- Ines Hübner
- Center
for Functional Protein Assemblies at the Department of Chemistry and
Chair of Organic Chemistry II, Technische
Universität München, Garching D-85748, Germany
| | - Justin A. Shapiro
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Jörn Hoßmann
- Microbial
Interactions and Processes Research Group, Helmholtz Centre for Infection Research, Braunschweig 38124, Germany
| | - Jonas Drechsel
- Center
for Functional Protein Assemblies at the Department of Chemistry and
Chair of Organic Chemistry II, Technische
Universität München, Garching D-85748, Germany
| | - Stephan M. Hacker
- Department
of Chemistry, Technische Universität
München, Garching D-85748, Germany
| | - Philip N. Rather
- Emory Antibiotic Resistance Center and Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia 30322, United States
- Research
Service, Atlanta VA Medical Center, Decatur, Georgia 30033, United States
| | - Dietmar H. Pieper
- Microbial
Interactions and Processes Research Group, Helmholtz Centre for Infection Research, Braunschweig 38124, Germany
| | - William M. Wuest
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
- Emory Antibiotic Resistance Center and Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia 30322, United States
| | - Stephan A. Sieber
- Center
for Functional Protein Assemblies at the Department of Chemistry and
Chair of Organic Chemistry II, Technische
Universität München, Garching D-85748, Germany
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27
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Chen TY, Chen J, Tang Y, Zhou J, Guo Y, Chang WC. Current Understanding toward Isonitrile Group Biosynthesis and Mechanism. CHINESE J CHEM 2021; 39:463-472. [PMID: 34658601 PMCID: PMC8519408 DOI: 10.1002/cjoc.202000448] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 09/21/2020] [Indexed: 12/20/2022]
Abstract
Isonitrile group has been identified in many natural products. Due to the broad reactivity of N≡C triple bond, these natural products have valuable pharmaceutical potentials. This review summarizes the current biosynthetic pathways and the corresponding enzymes that are responsible for isonitrile-containing natural product generation. Based on the strategies utilized, two fundamentally distinctive approaches are discussed. In addition, recent progress in elucidating isonitrile group formation mechanisms is also presented.
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Affiliation(s)
- Tzu-Yu Chen
- Department of Chemistry, North Carolina State University Raleigh, NC 27695, U.S.A
| | - Jinfeng Chen
- State Key Laboratory of Bio-organic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Shanghai 200032, China
| | - Yijie Tang
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, PA 15213, U.S.A
| | - Jiahai Zhou
- State Key Laboratory of Bio-organic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Shanghai 200032, China
- CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong 518055, China
| | - Yisong Guo
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, PA 15213, U.S.A
| | - Wei-chen Chang
- Department of Chemistry, North Carolina State University Raleigh, NC 27695, U.S.A
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28
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Liu J, Liu A, Hu Y. Enzymatic dimerization in the biosynthetic pathway of microbial natural products. Nat Prod Rep 2021; 38:1469-1505. [PMID: 33404031 DOI: 10.1039/d0np00063a] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Covering: up to August 2020The dramatic increase in the identification of dimeric natural products generated by microorganisms and plants has played a significant role in drug discovery. The biosynthetic pathways of these products feature inherent dimerization reactions, which are valuable for biosynthetic applications and chemical transformations. The extraordinary mechanisms of the dimerization of secondary metabolites should advance our understanding of the uncommon chemical rules for natural product biosynthesis, which will, in turn, accelerate the discovery of dimeric reactions and molecules in nature and provide promising strategies for the total synthesis of natural products through dimerization. This review focuses on the enzymes involved in the dimerization in the biosynthetic pathway of microbial natural products, with an emphasis on cytochrome P450s, laccases, and intermolecular [4 + 2] cyclases, along with other atypical enzymes. The identification, characterization, and catalytic landscapes of these enzymes are also introduced.
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Affiliation(s)
- Jiawang Liu
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China.
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29
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El Hajj Assaf C, Zetina-Serrano C, Tahtah N, Khoury AE, Atoui A, Oswald IP, Puel O, Lorber S. Regulation of Secondary Metabolism in the Penicillium Genus. Int J Mol Sci 2020; 21:E9462. [PMID: 33322713 PMCID: PMC7763326 DOI: 10.3390/ijms21249462] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 12/03/2020] [Accepted: 12/08/2020] [Indexed: 12/13/2022] Open
Abstract
Penicillium, one of the most common fungi occurring in a diverse range of habitats, has a worldwide distribution and a large economic impact on human health. Hundreds of the species belonging to this genus cause disastrous decay in food crops and are able to produce a varied range of secondary metabolites, from which we can distinguish harmful mycotoxins. Some Penicillium species are considered to be important producers of patulin and ochratoxin A, two well-known mycotoxins. The production of these mycotoxins and other secondary metabolites is controlled and regulated by different mechanisms. The aim of this review is to highlight the different levels of regulation of secondary metabolites in the Penicillium genus.
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Affiliation(s)
- Christelle El Hajj Assaf
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, 31027 Toulouse, France; (C.E.H.A.); (C.Z.-S.); (N.T.); (I.P.O.); (S.L.)
- Institute for Agricultural and Fisheries Research (ILVO), member of Food2Know, Brusselsesteenweg 370, 9090 Melle, Belgium
| | - Chrystian Zetina-Serrano
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, 31027 Toulouse, France; (C.E.H.A.); (C.Z.-S.); (N.T.); (I.P.O.); (S.L.)
| | - Nadia Tahtah
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, 31027 Toulouse, France; (C.E.H.A.); (C.Z.-S.); (N.T.); (I.P.O.); (S.L.)
- Centre D’analyse et de Recherche, Unité de Recherche Technologies et Valorisations Agro-Alimentaires, Faculté des Sciences, Université Saint-Joseph, P.O. Box 17-5208, Mar Mikhael, Beirut 1104, Lebanon;
| | - André El Khoury
- Centre D’analyse et de Recherche, Unité de Recherche Technologies et Valorisations Agro-Alimentaires, Faculté des Sciences, Université Saint-Joseph, P.O. Box 17-5208, Mar Mikhael, Beirut 1104, Lebanon;
| | - Ali Atoui
- Laboratory of Microbiology, Department of Life and Earth Sciences, Faculty of Sciences I, Lebanese University, Hadath Campus, P.O. Box 5, Beirut 1104, Lebanon;
| | - Isabelle P. Oswald
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, 31027 Toulouse, France; (C.E.H.A.); (C.Z.-S.); (N.T.); (I.P.O.); (S.L.)
| | - Olivier Puel
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, 31027 Toulouse, France; (C.E.H.A.); (C.Z.-S.); (N.T.); (I.P.O.); (S.L.)
| | - Sophie Lorber
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, 31027 Toulouse, France; (C.E.H.A.); (C.Z.-S.); (N.T.); (I.P.O.); (S.L.)
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30
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Misslinger M, Hortschansky P, Brakhage AA, Haas H. Fungal iron homeostasis with a focus on Aspergillus fumigatus. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1868:118885. [PMID: 33045305 DOI: 10.1016/j.bbamcr.2020.118885] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 09/15/2020] [Accepted: 10/01/2020] [Indexed: 02/08/2023]
Abstract
To maintain iron homeostasis, fungi have to balance iron acquisition, storage, and utilization to ensure sufficient supply and to avoid toxic excess of this essential trace element. As pathogens usually encounter iron limitation in the host niche, this metal plays a particular role during virulence. Siderophores are iron-chelators synthesized by most, but not all fungal species to sequester iron extra- and intracellularly. In recent years, the facultative human pathogen Aspergillus fumigatus has become a model for fungal iron homeostasis of siderophore-producing fungal species. This article summarizes the knowledge on fungal iron homeostasis and its links to virulence with a focus on A. fumigatus. It covers mechanisms for iron acquisition, storage, and detoxification, as well as the modes of transcriptional iron regulation and iron sensing in A. fumigatus in comparison to other fungal species. Moreover, potential translational applications of the peculiarities of fungal iron metabolism for treatment and diagnosis of fungal infections is addressed.
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Affiliation(s)
- Matthias Misslinger
- Institute of Molecular Biology - Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Peter Hortschansky
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute (HKI), Jena, Germany
| | - Axel A Brakhage
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute (HKI), Jena, Germany; Department Microbiology and Molecular Biology, Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Hubertus Haas
- Institute of Molecular Biology - Biocenter, Medical University of Innsbruck, Innsbruck, Austria.
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31
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Zhu M, Wang L, Zhang W, Liu Z, Ali M, Imtiaz M, He J. Diisonitrile-Mediated Reactive Oxygen Species Accumulation Leads to Bacterial Growth Inhibition. JOURNAL OF NATURAL PRODUCTS 2020; 83:1634-1640. [PMID: 32302148 DOI: 10.1021/acs.jnatprod.0c00125] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
The diisonitrile copper chelator SF2768 biosynthesized by Streptomyces thioluteus functions as a chalkophore that transports extracellular copper into producer cells in a complexed form. It was demonstrated that the treatment of eight bacteria, including Bacillus subtilis and Acinetobacter baumannii, with SF2768 led to a moderate growth inhibition which is associated with an increased level of reactive oxygen species (ROS). In addition, SF2768 and its diisonitrile analogues proved to be effective tyrosinase inhibitors. Three new analogues, SF2768 I, K, and L, were identified by detailed spectroscopic analysis.
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Affiliation(s)
- Mengyi Zhu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, People's Republic of China
| | - Lijuan Wang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, RNAM Center for Marine Microbiology, Guangdong Key Laboratory of Marine Materia Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, People's Republic of China
| | - Wei Zhang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, People's Republic of China
| | - Zhiwen Liu
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, RNAM Center for Marine Microbiology, Guangdong Key Laboratory of Marine Materia Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, People's Republic of China
| | - Muhammad Ali
- Department of Biotechnology, COMSATS University Islamabad, Abbottabad campus, Abbottabad 22060, Pakistan
| | - Muhammad Imtiaz
- Soil and Environmental Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Faisalabad 38000, Pakistan
| | - Jing He
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, People's Republic of China
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32
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Affiliation(s)
- Xinming Zhang
- CNRS, BioCIS; Université Paris-Saclay; 92290 Châtenay-Malabry France
| | - Laurent Evanno
- CNRS, BioCIS; Université Paris-Saclay; 92290 Châtenay-Malabry France
| | - Erwan Poupon
- CNRS, BioCIS; Université Paris-Saclay; 92290 Châtenay-Malabry France
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Lyu HN, Liu HW, Keller NP, Yin WB. Harnessing diverse transcriptional regulators for natural product discovery in fungi. Nat Prod Rep 2020; 37:6-16. [DOI: 10.1039/c8np00027a] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This review covers diverse transcriptional regulators for the activation of secondary metabolism and novel natural product discovery in fungi.
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Affiliation(s)
- Hai-Ning Lyu
- State Key Laboratory of Mycology
- Institute of Microbiology
- Chinese Academy of Sciences
- Beijing
- China
| | - Hong-Wei Liu
- State Key Laboratory of Mycology
- Institute of Microbiology
- Chinese Academy of Sciences
- Beijing
- China
| | - Nancy P. Keller
- Department of Medical Microbiology and Immunology and Bacteriology
- University of Wisconsin–Madison
- Madison
- USA
| | - Wen-Bing Yin
- State Key Laboratory of Mycology
- Institute of Microbiology
- Chinese Academy of Sciences
- Beijing
- China
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Jain KK, Kumar A, Shankar A, Pandey D, Chaudhary B, Sharma KK. De novo transcriptome assembly and protein profiling of copper-induced lignocellulolytic fungus Ganoderma lucidum MDU-7 reveals genes involved in lignocellulose degradation and terpenoid biosynthetic pathways. Genomics 2020; 112:184-198. [DOI: 10.1016/j.ygeno.2019.01.012] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 01/07/2019] [Accepted: 01/20/2019] [Indexed: 12/23/2022]
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Greco C, Pfannenstiel BT, Liu JC, Keller NP. Depsipeptide Aspergillicins Revealed by Chromatin Reader Protein Deletion. ACS Chem Biol 2019; 14:1121-1128. [PMID: 31117395 DOI: 10.1021/acschembio.9b00161] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Expression of biosynthetic gene clusters (BGCs) in filamentous fungi is highly regulated by epigenetic remodeling of chromatin structure. Two classes of histone modifying proteins, writers (which place modifications on histone tails) and erasers (which remove the modifications), have been used extensively to activate cryptic BGCs in fungi. Here, for the first time, we present activation of a cryptic BGC by a third category of histone modifying proteins, reader proteins that recognize histone tail modifications and commonly mediate writer and eraser activity. Loss of the reader SntB (Δ sntB) resulted in the synthesis of two cryptic cyclic hexa-depsipeptides, aspergillicin A and aspergillicin F, in the fungus Aspergillus flavus. Liquid chromatography, high resolution mass spectrometry, and NMR analysis coupled with bioinformatic analysis and gene deletion experiments revealed that a six adenylation (A) domain nonribosomal peptide synthetase (NRPS, called AgiA) and O-methyltransferase (AgiB) were required for metabolite formation. A proposed biosynthetic scheme illustrates the requirement for unusual NRPS domains, such as a starting condensation domain and a thiolesterase domain proposed to cyclize the depsipeptides. This latter activity has only been found in bacterial but not fungal NRPS. The agi BGC-unique to A. flavus and some closely related species (e.g., A. oryzae, A. arachidicola)-is located next to a conserved Aspergillus siderophore BGC syntenic to other fungi.
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Affiliation(s)
- Claudio Greco
- Department of Medical Microbiology and Immunology, University of Wisconsin—Madison, Madison, Wisconsin, United States
| | | | - James C. Liu
- Department of Medical Microbiology and Immunology, University of Wisconsin—Madison, Madison, Wisconsin, United States
| | - Nancy P. Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin—Madison, Madison, Wisconsin, United States
- Department of Bacteriology, University of Wisconsin—Madison, Madison, Wisconsin, United States
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Hunsaker EW, Franz KJ. Emerging Opportunities To Manipulate Metal Trafficking for Therapeutic Benefit. Inorg Chem 2019; 58:13528-13545. [PMID: 31247859 DOI: 10.1021/acs.inorgchem.9b01029] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The indispensable requirement for metals in life processes has led to the evolution of sophisticated mechanisms that allow organisms to maintain dynamic equilibria of these ions. This dynamic control of the level, speciation, and availability of a variety of metal ions allows organisms to sustain biological processes while avoiding toxicity. When functioning properly, these mechanisms allow cells to return to their metal homeostatic set points following shifts in the metal availability or other stressors. These periods of transition, when cells are in a state of flux in which they work to regain homeostasis, present windows of opportunity to pharmacologically manipulate targets associated with metal-trafficking pathways in ways that could either facilitate a return to homeostasis and the recovery of cellular function or further push cells outside of homeostasis and into cellular distress. The purpose of this Viewpoint is to highlight emerging opportunities for chemists and chemical biologists to develop compounds to manipulate metal-trafficking processes for therapeutic benefit.
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Affiliation(s)
- Elizabeth W Hunsaker
- Department of Chemistry , Duke University , French Family Science Center, 124 Science Drive , Durham , North Carolina 27708 , United States
| | - Katherine J Franz
- Department of Chemistry , Duke University , French Family Science Center, 124 Science Drive , Durham , North Carolina 27708 , United States
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Copper Utilization, Regulation, and Acquisition by Aspergillus fumigatus. Int J Mol Sci 2019; 20:ijms20081980. [PMID: 31018527 PMCID: PMC6514546 DOI: 10.3390/ijms20081980] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 04/16/2019] [Accepted: 04/17/2019] [Indexed: 01/01/2023] Open
Abstract
Copper is an essential micronutrient for the opportunistic human pathogen, Aspergillus fumigatus. Maintaining copper homeostasis is critical for survival and pathogenesis. Copper-responsive transcription factors, AceA and MacA, coordinate a complex network responsible for responding to copper in the environment and determining which response is necessary to maintain homeostasis. For example, A. fumigatus uses copper exporters to mitigate the toxic effects of copper while simultaneously encoding copper importers and small molecules to ensure proper supply of the metal for copper-dependent processes such a nitrogen acquisition and respiration. Small molecules called isocyanides recently found to be produced by A. fumigatus may bind copper and partake in copper homeostasis similarly to isocyanide copper chelators in bacteria. Considering that the host uses copper as a microbial toxin and copper availability fluctuates in various environmental niches, understanding how A. fumigatus maintains copper homeostasis will give insights into mechanisms that facilitate the development of invasive aspergillosis and its survival in nature.
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Raffa N, Keller NP. A call to arms: Mustering secondary metabolites for success and survival of an opportunistic pathogen. PLoS Pathog 2019; 15:e1007606. [PMID: 30947302 PMCID: PMC6448812 DOI: 10.1371/journal.ppat.1007606] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Affiliation(s)
- Nicholas Raffa
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Nancy P. Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- * E-mail:
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Abstract
One of the exciting movements in microbial sciences has been a refocusing and revitalization of efforts to mine the fungal secondary metabolome. The magnitude of biosynthetic gene clusters (BGCs) in a single filamentous fungal genome combined with the historic number of sequenced genomes suggests that the secondary metabolite wealth of filamentous fungi is largely untapped. Mining algorithms and scalable expression platforms have greatly expanded access to the chemical repertoire of fungal-derived secondary metabolites. In this Review, I discuss new insights into the transcriptional and epigenetic regulation of BGCs and the ecological roles of fungal secondary metabolites in warfare, defence and development. I also explore avenues for the identification of new fungal metabolites and the challenges in harvesting fungal-derived secondary metabolites.
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Eugenia Nuñez-Valdez M, Lanois A, Pagès S, Duvic B, Gaudriault S. Inhibition of Spodoptera frugiperda phenoloxidase activity by the products of the Xenorhabdus rhabduscin gene cluster. PLoS One 2019; 14:e0212809. [PMID: 30794697 PMCID: PMC6386379 DOI: 10.1371/journal.pone.0212809] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 02/08/2019] [Indexed: 12/15/2022] Open
Abstract
We evaluated the impact of bacterial rhabduscin synthesis on bacterial virulence and phenoloxidase inhibition in a Spodoptera model. We first showed that the rhabduscin cluster of the entomopathogenic bacterium Xenorhabdus nematophila was not necessary for virulence in the larvae of Spodoptera littoralis and Spodoptera frugiperda. Bacteria with mutations affecting the rhabduscin synthesis cluster (ΔisnAB and ΔGT mutants) were as virulent as the wild-type strain. We then developed an assay for measuring phenoloxidase activity in S. frugiperda and assessed the ability of bacterial culture supernatants to inhibit the insect phenoloxidase. Our findings confirm that the X. nematophila rhabduscin cluster is required for the inhibition of S. frugiperda phenoloxidase activity. The X. nematophila ΔisnAB mutant was unable to inhibit phenoloxidase, whereas ΔGT mutants displayed intermediate levels of phenoloxidase inhibition relative to the wild-type strain. The culture supernatants of Escherichia coli and of two entomopathogenic bacteria, Serratia entomophila and Xenorhabdus poinarii, were unable to inhibit S. frugiperda phenoloxidase activity. Heterologous expression of the X. nematophila rhabduscin cluster in these three strains was sufficient to restore inhibition. Interestingly, we observed pseudogenization of the X. poinarii rhabduscin gene cluster via the insertion of a 120 bp element into the isnA promoter. The inhibition of phenoloxidase activity by X. poinarii culture supernatants was restored by expression of the X. poinarii rhabduscin cluster under the control of an inducible Ptet promoter, consistent with recent pseudogenization. This study paves the way for advances in our understanding of the virulence of several entomopathogenic bacteria in non-model insects, such as the new invasive S. frugiperda species in Africa.
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Affiliation(s)
| | - Anne Lanois
- DGIMI, INRA, Université de Montpellier, Montpellier, France
| | - Sylvie Pagès
- DGIMI, INRA, Université de Montpellier, Montpellier, France
| | - Bernard Duvic
- DGIMI, INRA, Université de Montpellier, Montpellier, France
| | - Sophie Gaudriault
- DGIMI, INRA, Université de Montpellier, Montpellier, France
- * E-mail: (MENV); (SG)
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