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Cui JJ, Zhang Y, Ju KS. Phosphonoalamides Reveal the Biosynthetic Origin of Phosphonoalanine Natural Products and a Convergent Pathway for Their Diversification. Angew Chem Int Ed Engl 2024; 63:e202405052. [PMID: 38780891 DOI: 10.1002/anie.202405052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 05/18/2024] [Accepted: 05/23/2024] [Indexed: 05/25/2024]
Abstract
Phosphonate natural products, with their potent inhibitory activity, have found widespread use across multiple industries. Their success has inspired development of genome mining approaches that continue to reveal previously unknown bioactive scaffolds and biosynthetic insights. However, a greater understanding of phosphonate metabolism is required to enable prediction of compounds and their bioactivities from sequence information alone. Here, we expand our knowledge of this natural product class by reporting the complete biosynthesis of the phosphonoalamides, antimicrobial tripeptides with a conserved N-terminal l-phosphonoalanine (PnAla) residue produced by Streptomyces. The phosphonoalamides result from the convergence of PnAla biosynthesis and peptide ligation pathways. We elucidate the biochemistry underlying the transamination of phosphonopyruvate to PnAla, a new early branchpoint in phosphonate biosynthesis catalyzed by an aminotransferase with evolved specificity for phosphonate metabolism. Peptide formation is catalyzed by two ATP-grasp ligases, the first of which produces dipeptides, and a second which ligates dipeptides to PnAla to produce phosphonoalamides. Substrate specificity profiling revealed a dramatic expansion of dipeptide and tripeptide products, while finding PnaC to be the most promiscuous dipeptide ligase reported thus far. Our findings highlight previously unknown transformations in natural product biosynthesis, promising enzyme biocatalysts, and unveil insights into the diversity of phosphonopeptide natural products.
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Affiliation(s)
- Jerry J Cui
- Department of Microbiology, The Ohio State University, 318W. 12th Ave, Columbus, OH-43210, USA
| | - Yeying Zhang
- Department of Microbiology, The Ohio State University, 318W. 12th Ave, Columbus, OH-43210, USA
| | - Kou-San Ju
- Department of Microbiology, The Ohio State University, 318W. 12th Ave, Columbus, OH-43210, USA
- Division of Medicinal Chemistry and Pharmacognosy, Center for Applied Plant Sciences, Infectious Disease Institute, The Ohio State University, 318W. 12th Ave, Columbus, OH-43210, USA
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2
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Cui J, Ju KS. Biosynthesis of Bacillus Phosphonoalamides Reveals Highly Specific Amino Acid Ligation. ACS Chem Biol 2024; 19:1506-1514. [PMID: 38885091 PMCID: PMC11259534 DOI: 10.1021/acschembio.4c00190] [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] [Indexed: 06/20/2024]
Abstract
Phosphonate natural products have a history of commercial success across numerous industries due to their potent inhibition of metabolic processes. Over the past decade, genome mining approaches have successfully led to the discovery of numerous bioactive phosphonates. However, continued success is dependent upon a greater understanding of phosphonate metabolism, which will enable the prioritization and prediction of biosynthetic gene clusters for targeted isolation. Here, we report the complete biosynthetic pathway for phosphonoalamides E and F, antimicrobial phosphonopeptides with a conserved C-terminal l-phosphonoalanine (PnAla) residue. These peptides, produced by Bacillus, are the direct result of PnAla biosynthesis and serial ligation by two ATP-grasp ligases. A critical step of this pathway was the reversible transamination of phosphonopyruvate to PnAla by a dedicated transaminase with preference for the forward reaction. The dipeptide ligase PnfA was shown to ligate alanine to PnAla to afford phosphonoalamide E, which was subsequently ligated to alanine by PnfB to form phosphonoalamide F. Specificity profiling of both ligases found each to be highly specific, although the limited acceptance of noncanonical substrates by PnfA allowed for in vitro formation of products incorporating alternative pharmacophores. Our findings further establish the transaminative branch of phosphonate metabolism, unveil insights into the specificity of ATP-grasp ligation, and highlight the biocatalytic potential of biosynthetic enzymes.
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Affiliation(s)
- Jerry Cui
- Department of Microbiology, The Ohio State University, Columbus, Ohio 43210, United States
| | - Kou-San Ju
- Department of Microbiology, The Ohio State University, Columbus, Ohio 43210, United States
- Division of Medicinal Chemistry and Pharmacognosy, The Ohio State University, Columbus, Ohio 43210, United States
- Center for Applied Plant Sciences, The Ohio State University, Columbus, Ohio 43210, United States
- Infectious Diseases Institute, The Ohio State University, Columbus, Ohio 43210, United States
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3
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Bown L, Hirota R, Goettge MN, Cui J, Krist DT, Zhu L, Giurgiu C, van der Donk WA, Ju KS, Metcalf WW. A Novel Pathway for Biosynthesis of the Herbicidal Phosphonate Natural Product Phosphonothrixin Is Widespread in Actinobacteria. J Bacteriol 2023; 205:e0048522. [PMID: 37074199 PMCID: PMC10210982 DOI: 10.1128/jb.00485-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 03/23/2023] [Indexed: 04/20/2023] Open
Abstract
Phosphonothrixin is an herbicidal phosphonate natural product with an unusual, branched carbon skeleton. Bioinformatic analyses of the ftx gene cluster, which is responsible for synthesis of the compound, suggest that early steps of the biosynthetic pathway, up to production of the intermediate 2,3-dihydroxypropylphosphonic acid (DHPPA) are identical to those of the unrelated phosphonate natural product valinophos. This conclusion was strongly supported by the observation of biosynthetic intermediates from the shared pathway in spent media from two phosphonothrixin producing strains. Biochemical characterization of ftx-encoded proteins confirmed these early steps, as well as subsequent steps involving the oxidation of DHPPA to 3-hydroxy-2-oxopropylphosphonate and its conversion to phosphonothrixin by the combined action of an unusual heterodimeric, thiamine-pyrophosphate (TPP)-dependent ketotransferase and a TPP-dependent acetolactate synthase. The frequent observation of ftx-like gene clusters within actinobacteria suggests that production of compounds related to phosphonothrixin is common within these bacteria. IMPORTANCE Phosphonic acid natural products, such as phosphonothrixin, have great potential for biomedical and agricultural applications; however, discovery and development of these compounds requires detailed knowledge of the metabolism involved in their biosynthesis. The studies reported here reveal the biochemical pathway phosphonothrixin production, which enhances our ability to design strains that overproduce this potentially useful herbicide. This knowledge also improves our ability to predict the products of related biosynthetic gene clusters and the functions of homologous enzymes.
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Affiliation(s)
- Luke Bown
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Ryuichi Hirota
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima City, Hiroshima, Japan
| | - Michelle N. Goettge
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Jerry Cui
- Department of Microbiology, The Ohio State University, Columbus, Ohio, USA
| | - David T. Krist
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Lingyang Zhu
- Department of Chemistry and the Howard Hughes Medical Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Constantin Giurgiu
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Wilfred A. van der Donk
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- Department of Chemistry and the Howard Hughes Medical Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Kou-San Ju
- Department of Microbiology, The Ohio State University, Columbus, Ohio, USA
- Division of Medicinal Chemistry and Pharmacognosy, The Ohio State University, Columbus, Ohio, USA
- Infectious Diseases Institute, The Ohio State University, Columbus, Ohio, USA
- Center for Applied Plant Sciences, The Ohio State University, Columbus, Ohio, USA
| | - William W. Metcalf
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
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4
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The functional importance of bacterial oxidative phosphonate pathways. Biochem Soc Trans 2023; 51:487-499. [PMID: 36892197 DOI: 10.1042/bst20220479] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 02/21/2023] [Accepted: 02/23/2023] [Indexed: 03/10/2023]
Abstract
Organophosphonates (Pns) are a unique class of natural products characterized by a highly stable C-P bond. Pns exhibit a wide array of interesting structures as well as useful bioactivities ranging from antibacterial to herbicidal. More structurally simple Pns are scavenged and catabolized by bacteria as a source of phosphorus. Despite their environmental and industrial importance, the pathways involved in the metabolism of Pns are far from being fully elucidated. Pathways that have been characterized often reveal unusual chemical transformations and new enzyme mechanisms. Among these, oxidative enzymes play an outstanding role during the biosynthesis and degradation of Pns. They are to a high extent responsible for the structural diversity of Pn secondary metabolites and for the break-down of both man-made and biogenic Pns. Here, we review our current understanding of the importance of oxidative enzymes for microbial Pn metabolism, discuss the underlying mechanistic principles, similarities, and differences between pathways. This review illustrates Pn biochemistry to involve a mix of classical redox biochemistry and unique oxidative reactions, including ring formations, rearrangements, and desaturations. Many of these reactions are mediated by specialized iron-dependent oxygenases and oxidases. Such enzymes are the key to both early pathway diversification and late-stage functionalization of complex Pns.
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Amino acid (acyl carrier protein) ligase-associated biosynthetic gene clusters reveal unexplored biosynthetic potential. Mol Genet Genomics 2023; 298:49-65. [PMID: 36271918 DOI: 10.1007/s00438-022-01962-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 10/09/2022] [Indexed: 01/10/2023]
Abstract
This study aimed to evaluate the postulated cellular function of a novel family of amino acid (acyl carrier protein) ligases (AALs) in natural product biosynthesis. Here, we analyzed the manually curated, putative, aal-associated natural product biosynthetic gene clusters (NP BGCs) using two computational platforms for NP prediction, antiSMASH-BiG-SCAPE-CORASON and DeepBGC. The detected BGCs included a diversity of type I polyketide/nonribosomal peptide (PKS/NRPS) hybrid BGCs, exemplified by the guadinomine BGC, which suggested a dedicated function of AALs in the biosynthesis of rare (2S)-aminomalonyl-ACP extension units. Besides modular PKS/NRPSs and NRPSs, AAL-associated BGCs were predicted to assemble arylpolyenes, ladderane lipids, phosphonates, aminoglycosides, β-lactones, and thioamides of both nonribosomal and ribosomal origins. Additionally, we revealed a frequent association of AALs with putative, seldom observed transglutaminase-like and BtrH-like transferases of the cysteine protease superfamily, which may form larger families of ACP-dependent amide bond catalysts used in NP synthesis. Our results disclosed an exceptional chemical novelty and biosynthetic potential of the AAL-associated BGCs in NP biosynthesis. The presented in silico evidence supports the initial hypothesis and provides an important foundation for future experimental studies aimed at discovering novel pharmaceutically relevant active compounds.
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Ju KS, Nair SK. Convergent and divergent biosynthetic strategies towards phosphonic acid natural products. Curr Opin Chem Biol 2022; 71:102214. [PMID: 36202046 PMCID: PMC9722595 DOI: 10.1016/j.cbpa.2022.102214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 08/31/2022] [Accepted: 09/05/2022] [Indexed: 01/27/2023]
Abstract
The phosphonate class of natural products have received significant interests in the post-genomic era due to the relative ease with which their biosynthetic genes may be identified and the resultant final products be characterized. Recent large-scale studies of the elucidation and distributions of phosphonate pathways have provided a robust landscape for deciphering the underlying biosynthetic logic. A recurrent theme in phosphonate biosynthetic pathways is the interweaving of enzymatic reactions across different routes, which enables diversification to elaborate chemically novel scaffolds. Here, we provide a few vignettes of how Nature has utilized both convergent and divergent biosynthetic strategies to compile pathways for production of novel phosphonates. These examples illustrate how common intermediates may either be generated or intercepted to diversify chemical scaffolds and provides a starting point for both biotechnological and synthetic biological applications towards new phosphonates by similar combinatorial approaches.
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Affiliation(s)
- Kou-San Ju
- Department of Microbiology, The Ohio State University, Columbus OH 43210,Division of Medicinal Chemistry and Pharmacognosy, The Ohio State University, Columbus OH 43210,Infectious Diseases Institute. The Ohio State University, Columbus OH 43210,Corresponding authors: Kou-San Ju () and Satish K. Nair ()
| | - Satish K. Nair
- Department of Biochemistry, University of Illinois, Urbana, IL 61801,Center for Biophysics and Quantitative Biology, University of Illinois, Urbana, IL 61801,Carl Woese Institute for Genomic Biology. University of Illinois, Urbana, IL 61801,Corresponding authors: Kou-San Ju () and Satish K. Nair ()
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7
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Zhang Y, Chen L, Wilson JA, Cui J, Roodhouse H, Kayrouz C, Pham TM, Ju KS. Valinophos Reveals a New Route in Microbial Phosphonate Biosynthesis That Is Broadly Conserved in Nature. J Am Chem Soc 2022; 144:9938-9948. [PMID: 35617676 PMCID: PMC9284248 DOI: 10.1021/jacs.2c02854] [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: 01/30/2023]
Abstract
Phosphonate natural products are potent inhibitors of cellular metabolism with an established record of commercialization in medicine and biotechnology. Although genome mining has emerged as an accelerated method for the discovery of new phosphonates, a robust framework of their metabolism is needed to identify the pathways most likely to yield compounds with desired activities. Here we expand our understanding of these natural products by reporting the complete biosynthetic pathway for valinophos, a phosphonopeptide natural product containing the unusual (R)-2,3-dihydroxypropylphosphonate (DHPPA) scaffold. The pathway was defined by several enzymatic transformations and intermediates previously unknown to phosphonate natural products. A dedicated dehydrogenase served as a new phosphoenolpyruvate mutase coupling enzyme. Notably, its reduction of phosphonopyruvate to phosphonolactate defined a new early branchpoint in phosphonate biosynthesis. Functionally interconnected kinase and reductase enzymes catalyzed reactions reminiscent of glycolysis and arginine biosynthesis to produce a transient, but essential, phosphonolactaldehyde intermediate. We demonstrate esterification of l-valine onto DHPPA as a new biochemical activity for ATP-Grasp ligase enzymes. Unexpectedly, a second amino acid ligase then adjoined additional amino acids at the valinyl moiety to produce a suite of DHPPA-dipeptides. The genes for DHPPA biosynthesis were discovered among genomes of bacteria from wide-ranging habitats, suggesting a wealth of unknown compounds that may originate from this core pathway. Our findings establish new biosynthetic principles for natural products and provide definition to unexplored avenues for bioactive phosphonate genome mining.
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Affiliation(s)
- Yeying Zhang
- Department of Microbiology, The Ohio State University, Columbus, Ohio 43210, United States
| | - Li Chen
- Department of Microbiology, The Ohio State University, Columbus, Ohio 43210, United States
| | - Jake A Wilson
- Department of Microbiology, The Ohio State University, Columbus, Ohio 43210, United States
- Division of Medicinal Chemistry and Pharmacognosy, The Ohio State University, Columbus, Ohio 43210, United States
| | - Jerry Cui
- Department of Microbiology, The Ohio State University, Columbus, Ohio 43210, United States
| | - Hannah Roodhouse
- Department of Microbiology, The Ohio State University, Columbus, Ohio 43210, United States
| | - Chase Kayrouz
- Department of Microbiology, The Ohio State University, Columbus, Ohio 43210, United States
| | - Tiffany M Pham
- Department of Microbiology, The Ohio State University, Columbus, Ohio 43210, United States
| | - Kou-San Ju
- Department of Microbiology, The Ohio State University, Columbus, Ohio 43210, United States
- Division of Medicinal Chemistry and Pharmacognosy, The Ohio State University, Columbus, Ohio 43210, United States
- Center for Applied Plant Sciences, The Ohio State University, Columbus, Ohio 43210, United States
- Infectious Diseases Institute, The Ohio State University, Columbus, Ohio 43210, United States
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8
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Zhang Y, Pham TM, Kayrouz C, Ju KS. Biosynthesis of Argolaphos Illuminates the Unusual Biochemical Origins of Aminomethylphosphonate and N ε-Hydroxyarginine Containing Natural Products. J Am Chem Soc 2022; 144:9634-9644. [PMID: 35616638 DOI: 10.1021/jacs.2c00627] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Phosphonate natural products have a history of successful application in medicine and biotechnology due to their ability to inhibit essential cellular pathways. This has inspired efforts to discover phosphonate natural products by prioritizing microbial strains whose genomes encode uncharacterized biosynthetic gene clusters (BGCs). Thus, success in genome mining is dependent on establishing the fundamental principles underlying the biosynthesis of inhibitory chemical moieties to facilitate accurate prediction of BGCs and the bioactivities of their products. Here, we report the complete biosynthetic pathway for the argolaphos phosphonopeptides. We uncovered the biochemical origins of aminomethylphosphonate (AMPn) and Nε-hydroxyarginine, two noncanonical amino acids integral to the antimicrobial function of argolaphos. Critical to this pathway were dehydrogenase and transaminase enzymes dedicated to the conversion of hydroxymethylphosphonate to AMPn. The interconnected activities of both enzymes provided a solution to overcome unfavorable energetics, empower cofactor regeneration, and mediate intermediate toxicity during these transformations. Sequential ligation of l-arginine and l-valine was afforded by two GCN5-related N-acetyltransferases in a tRNA-dependent manner. AglA was revealed to be an unusual heme-dependent monooxygenase that hydroxylated the Nε position of AMPn-Arg. As the first biochemically characterized member of the YqcI/YcgG protein family, AglA enlightens the potential functions of this elusive group, which remains biochemically distinct from the well-established P450 monooxygenases. The widespread distribution of AMPn and YqcI/YcgG genes among actinobacterial genomes suggests their involvement in diverse metabolic pathways and cellular functions. Our findings illuminate new paradigms in natural product biosynthesis and realize a significant trove of AmPn and Nε-hydroxyarginine natural products that await discovery.
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Affiliation(s)
- Yeying Zhang
- Department of Microbiology, The Ohio State University, Columbus, Ohio 43210, United States
| | - Tiffany M Pham
- Department of Microbiology, The Ohio State University, Columbus, Ohio 43210, United States
| | - Chase Kayrouz
- Department of Microbiology, The Ohio State University, Columbus, Ohio 43210, United States
| | - Kou-San Ju
- Department of Microbiology, The Ohio State University, Columbus, Ohio 43210, United States.,Division of Medicinal Chemistry and Pharmacognosy, The Ohio State University, Columbus, Ohio 43210, United States.,Center for Applied Plant Sciences, The Ohio State University, Columbus, Ohio 43210, United States.,Infectious Diseases Institute, The Ohio State University, Columbus, Ohio 43210, United States
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Gama SR, Stankovic T, Hupp K, Al Hejami A, McClean M, Evans A, Beauchemin D, Hammerschmidt F, Pallitsch K, Zechel DL. Biosynthesis of the Fungal Organophosphonate Fosfonochlorin Involves an Iron(II) and 2-(Oxo)glutarate Dependent Oxacyclase. Chembiochem 2021; 23:e202100352. [PMID: 34375042 DOI: 10.1002/cbic.202100352] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 08/09/2021] [Indexed: 11/07/2022]
Abstract
The fungal metabolite Fosfonochlorin features a chloroacetyl moiety that is unusual within known phosphonate natural product biochemistry. Putative biosynthetic genes encoding Fosfonochlorin in Fusarium and Talaromyces spp. were investigated through reactions of encoded enzymes with synthetic substrates and isotope labelling studies. We show that early biosynthetic steps for Fosfonochlorin involves the reduction of phosphonoacetaldehyde to form 2-hydroxyethylphosphonic acid, followed by oxidative intramolecular cyclization of the resulting alcohol to form ( S )-epoxyethylphosphonic acid. The latter reaction is catalyzed by FfnD, a rare example of a non-heme iron / 2-(oxo)glutarate dependent oxacyclase. In contrast, FfnD behaves as a more typical oxygenase with ethylphosphonic acid, producing ( S )-1-hydroxyethylphosphonic acid. FfnD thus represents a new example of a ferryl generating enzyme that can suppress the typical oxygen rebound reaction that follows abstraction of a substrate hydrogen by a ferryl oxygen, thereby directing the substrate radical towards a fate other than hydroxylation.
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Affiliation(s)
- Simanga R Gama
- Department of Chemistry, Queen's University, Kingston, Ontario, K7L 3N6, Canada
| | - Toda Stankovic
- Institut für Organische Chemie, Universität Wien, 1090, Wien, Österreich
| | - Kendall Hupp
- Department of Chemistry, Queen's University, Kingston, Ontario, K7L 3N6, Canada
| | - Ahmed Al Hejami
- Department of Chemistry, Queen's University, Kingston, Ontario, K7L 3N6, Canada
| | - Mimi McClean
- Department of Chemistry, Queen's University, Kingston, Ontario, K7L 3N6, Canada
| | - Alysa Evans
- Department of Chemistry, Queen's University, Kingston, Ontario, K7L 3N6, Canada
| | - Diane Beauchemin
- Department of Chemistry, Queen's University, Kingston, Ontario, K7L 3N6, Canada
| | | | | | - David L Zechel
- Department of Chemistry, Queen's University, Kingston, Ontario, K7L 3N6, Canada
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Zhou C, Luo X, Chen N, Zhang L, Gao J. C-P Natural Products as Next-Generation Herbicides: Chemistry and Biology of Glufosinate. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:3344-3353. [PMID: 32125843 DOI: 10.1021/acs.jafc.0c00052] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
In modern agriculture and weed management practices, herbicides have been widely used to control weeds effectively and represent more than 50% of commercial pesticides applied in the world. Herbicides with unique mechanisms of actions (MOA) have historically been discovered and commercialized every two or three years from the 1950s to the 1980s. However, this trend lowered dramatically as no herbicide with a novel MOA has been marketed for more than 30 years. The fast-growing resistance to commercial herbicides has reignited the agricultural chemical industry interest in new structural scaffolds targeting novel sites in plants. Carbon-phosphorus bonds (C-P) containing natural products (NPs) have played an essential role in herbicide discovery as the chemical diversity, and the promising bioactivity of natural C-P phytotoxins can provide exciting opportunities for the discovery of both natural and semisynthetic herbicides with novel targets. Among commercial herbicides, glyphosate (Roundup), a famous C-P containing herbicide, is by far the most universally used herbicide worldwide. Furthermore, glufosinate is one of the most widely used natural herbicides in the world. Therefore, C-P NPs are a treasure for discovering new herbicides with novel mechanisms of actions (MOAs). Here, we present an overview of the chemistry and biology of glufosinate including isolation and characterization, mode of action, herbicidal use, biosynthesis, and chemical synthesis since its discovery in order to not only help scientists reassess the role of this famous herbicide in the field of agrichemical chemistry but also build a new stage for discovering novel C-P herbicides with new MOAs.
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Affiliation(s)
- Chengzeng Zhou
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Xiaoxia Luo
- Key Laboratory of Protection and Utilization of Biological Resources in Tarim Basin of Xinjiang Production & Construction Corps, College of Life Science, Tarim University, Alar 843300, China
| | - Nengyi Chen
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Lili Zhang
- Key Laboratory of Protection and Utilization of Biological Resources in Tarim Basin of Xinjiang Production & Construction Corps, College of Life Science, Tarim University, Alar 843300, China
| | - Jiangtao Gao
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
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11
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Gama SR, Vogt M, Kalina T, Hupp K, Hammerschmidt F, Pallitsch K, Zechel DL. An Oxidative Pathway for Microbial Utilization of Methylphosphonic Acid as a Phosphate Source. ACS Chem Biol 2019; 14:735-741. [PMID: 30810303 DOI: 10.1021/acschembio.9b00024] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Methylphosphonic acid is synthesized by marine bacteria and is a prominent component of dissolved organic phosphorus. Consequently, methylphosphonic acid also serves as a source of inorganic phosphate (Pi) for marine bacteria that are starved of this nutrient. Conversion of methylphosphonic acid into Pi is currently only known to occur through the carbon-phosphorus lyase pathway, yielding methane as a byproduct. In this work, we describe an oxidative pathway for the catabolism of methylphosphonic acid in Gimesia maris DSM8797. G. maris can use methylphosphonic acid as Pi sources despite lacking a phn operon encoding a carbon-phosphorus lyase pathway. Instead, the genome contains a locus encoding homologues of the non-heme Fe(II) dependent oxygenases HF130PhnY* and HF130PhnZ, which were previously shown to convert 2-aminoethylphosphonic acid into glycine and Pi. GmPhnY* and GmPhnZ1 were produced in E. coli and purified for characterization in vitro. The substrate specificities of the enzymes were evaluated with a panel of synthetic phosphonates. Via 31P NMR spectroscopy, it is demonstrated that the GmPhnY* converts methylphosphonic acid to hydroxymethylphosphonic acid, which in turn is oxidized by GmPhnZ1 to produce formic acid and Pi. In contrast, 2-aminoethylphosphonic acid is not a substrate for GmPhnY* and is therefore not a substrate for this pathway. These results thus reveal a new metabolic fate for methylphosphonic acid.
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Affiliation(s)
- Simanga R. Gama
- Department of Chemistry, Queen’s University, Kingston, Ontario, Canada
| | - Margret Vogt
- Institute of Organic Chemistry, University of Vienna, Vienna, Austria
| | - Thomas Kalina
- Institute of Organic Chemistry, University of Vienna, Vienna, Austria
| | - Kendall Hupp
- Department of Chemistry, Queen’s University, Kingston, Ontario, Canada
| | | | | | - David L. Zechel
- Department of Chemistry, Queen’s University, Kingston, Ontario, Canada
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12
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Bougioukou DJ, Ting CP, Peck SC, Mukherjee S, van der Donk WA. Use of the dehydrophos biosynthetic enzymes to prepare antimicrobial analogs of alaphosphin. Org Biomol Chem 2019; 17:822-829. [PMID: 30608108 DOI: 10.1039/c8ob02860e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The C-terminal domain of the dehydrophos biosynthetic enzyme DhpH (DhpH-C) catalyzes the condensation of Leu-tRNALeu with (R)-1-aminoethylphosphonate, the aminophosphonate analog of alanine called Ala(P). The product of this reaction, Leu-Ala(P), is a phosphonodipeptide, a class of compounds that have previously been investigated for use as clinical antibiotics. In this study, we show that DhpH-C is highly substrate tolerant and can condense various aminophosphonates (Gly(P), Ser(P), Val(P), 1-amino-propylphosphonate, and phenylglycine(P)) to Leu. Moreover, the enzyme is also tolerant with respect to the amino acid attached to tRNALeu. Using a mutant of leucyl tRNA synthetase that is deficient in its proofreading ability allowed the preparation of a series of aminoacyl-tRNALeu derivatives (Ile, Ala, Val, Met, norvaline, and norleucine). DhpH-C accepted these aminoacyl-tRNA derivatives and condensed the amino acid with l-Ala(P) to form the corresponding phosphonodipeptides. A subset of these peptides displayed antimicrobial activities demonstrating that the enzyme is a versatile biocatalyst for the preparation of antimicrobial peptides. We also investigated another enzyme from the dehydrophos biosynthetic pathway, the 2-oxoglutarate dependent enzyme DhpA. This enzyme oxidizes 2-hydroxyethylphosphonate to 1,2-dihydroxyethylphosphonate en route to l-Ala(P), but longer incubation results in overoxidation to 1-oxo-2-hydroxyethylphosphonate. This α-ketophosphonate was converted by the pyridoxal phosphate dependent enzyme DhpD into l-Ser(P). Thus, the dehydrophos biosynthetic enzymes can generate not only l-Ala(P) but also l-Ser(P).
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Affiliation(s)
- Despina J Bougioukou
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, IL 61801, USA.
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Jiménez-Andreu MM, Lucía Quintana A, Aínsa JA, Sayago FJ, Cativiela C. Synthesis and biological activity of dehydrophos derivatives. Org Biomol Chem 2019; 17:1097-1112. [PMID: 30633297 DOI: 10.1039/c8ob03079k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The synthesis of dehydrophos derivatives featuring modified peptide chains, characterized by the presence of substituents in the vinyl moiety, or possessing a phosphonic acid monoalkyl ester other than the monomethyl ester one, has been accomplished by a versatile procedure based on Horner-Wadsworth-Emmons olefination with suitable aldehydes and on the selective hydrolysis of the dialkyl phosphonate group. Such derivatives have been tested against a series of bacterial strains, using the naturally occurring peptide, dehydrophos, for comparison. Thus, the effects of the aforementioned structural variations on antimicrobial activity have been studied.
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Affiliation(s)
- M Mercedes Jiménez-Andreu
- Departamento de Química Orgánica, Instituto de Síntesis Química y Catálisis Homogénea ISQCH, CSIC-Universidad de Zaragoza, Zaragoza 50009, Spain.
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14
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Nepal KK, Wang G. Streptomycetes: Surrogate hosts for the genetic manipulation of biosynthetic gene clusters and production of natural products. Biotechnol Adv 2019; 37:1-20. [PMID: 30312648 PMCID: PMC6343487 DOI: 10.1016/j.biotechadv.2018.10.003] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 09/04/2018] [Accepted: 10/05/2018] [Indexed: 12/23/2022]
Abstract
Due to the worldwide prevalence of multidrug-resistant pathogens and high incidence of diseases such as cancer, there is an urgent need for the discovery and development of new drugs. Nearly half of the FDA-approved drugs are derived from natural products that are produced by living organisms, mainly bacteria, fungi, and plants. Commercial development is often limited by the low yield of the desired compounds expressed by the native producers. In addition, recent advances in whole genome sequencing and bioinformatics have revealed an abundance of cryptic biosynthetic gene clusters within microbial genomes. Genetic manipulation of clusters in the native host is commonly used to awaken poorly expressed or silent gene clusters, however, the lack of feasible genetic manipulation systems in many strains often hinders our ability to engineer the native producers. The transfer of gene clusters into heterologous hosts for expression of partial or entire biosynthetic pathways is an approach that can be used to overcome this limitation. Heterologous expression also facilitates the chimeric fusion of different biosynthetic pathways, leading to the generation of "unnatural" natural products. The genus Streptomyces is especially known to be a prolific source of drugs/antibiotics, its members are often used as heterologous expression hosts. In this review, we summarize recent applications of Streptomyces species, S. coelicolor, S. lividans, S. albus, S. venezuelae and S. avermitilis, as heterologous expression systems.
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Affiliation(s)
- Keshav K Nepal
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 U.S. 1 North, Fort Pierce, FL 34946, USA
| | - Guojun Wang
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 U.S. 1 North, Fort Pierce, FL 34946, USA.
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15
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Gao SS, Naowarojna N, Cheng R, Liu X, Liu P. Recent examples of α-ketoglutarate-dependent mononuclear non-haem iron enzymes in natural product biosyntheses. Nat Prod Rep 2018; 35:792-837. [PMID: 29932179 PMCID: PMC6093783 DOI: 10.1039/c7np00067g] [Citation(s) in RCA: 104] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Covering: up to 2018 α-Ketoglutarate (αKG, also known as 2-oxoglutarate)-dependent mononuclear non-haem iron (αKG-NHFe) enzymes catalyze a wide range of biochemical reactions, including hydroxylation, ring fragmentation, C-C bond cleavage, epimerization, desaturation, endoperoxidation and heterocycle formation. These enzymes utilize iron(ii) as the metallo-cofactor and αKG as the co-substrate. Herein, we summarize several novel αKG-NHFe enzymes involved in natural product biosyntheses discovered in recent years, including halogenation reactions, amino acid modifications and tailoring reactions in the biosynthesis of terpenes, lipids, fatty acids and phosphonates. We also conducted a survey of the currently available structures of αKG-NHFe enzymes, in which αKG binds to the metallo-centre bidentately through either a proximal- or distal-type binding mode. Future structure-function and structure-reactivity relationship investigations will provide crucial information regarding how activities in this large class of enzymes have been fine-tuned in nature.
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Affiliation(s)
- Shu-Shan Gao
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | | | - Ronghai Cheng
- Department of Chemistry, Boston University, Boston, MA 02215, USA.
| | - Xueting Liu
- Department of Chemistry, Boston University, Boston, MA 02215, USA. and State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China.
| | - Pinghua Liu
- Department of Chemistry, Boston University, Boston, MA 02215, USA.
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16
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Jiménez-Andreu MM, Sayago FJ, Cativiela C. An Improved Synthesis of the Antibiotic Dehydrophos. European J Org Chem 2018. [DOI: 10.1002/ejoc.201800689] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- M. Mercedes Jiménez-Andreu
- Departamento de Química Orgánica; Instituto de Síntesis Química y Catálisis Homogénea (ISQCH); CSIC-Universidad de Zaragoza; 50009 Zaragoza Spain
| | - Francisco J. Sayago
- Departamento de Química Orgánica; Instituto de Síntesis Química y Catálisis Homogénea (ISQCH); CSIC-Universidad de Zaragoza; 50009 Zaragoza Spain
| | - Carlos Cativiela
- Departamento de Química Orgánica; Instituto de Síntesis Química y Catálisis Homogénea (ISQCH); CSIC-Universidad de Zaragoza; 50009 Zaragoza Spain
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17
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Pallitsch K, Rogers MP, Andrews FH, Hammerschmidt F, McLeish MJ. Phosphonodifluoropyruvate is a mechanism-based inhibitor of phosphonopyruvate decarboxylase from Bacteroides fragilis. Bioorg Med Chem 2017; 25:4368-4374. [PMID: 28693916 DOI: 10.1016/j.bmc.2017.06.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 06/11/2017] [Accepted: 06/12/2017] [Indexed: 10/19/2022]
Abstract
Bacteroides fragilis, a human pathogen, helps in the formation of intra-abdominal abscesses and is involved in 90% of anaerobic peritoneal infections. Phosphonopyruvate decarboxylase (PnPDC), a thiamin diphosphate (ThDP)-dependent enzyme, plays a key role in the formation of 2-aminoethylphosphonate, a component of the cell wall of B. fragilis. As such PnPDC is a possible target for therapeutic intervention in this, and other phosphonate producing organisms. However, the enzyme is of more general interest as it appears to be an evolutionary forerunner to the decarboxylase family of ThDP-dependent enzymes. To date, PnPDC has proved difficult to crystallize and no X-ray structures are available. In the past we have shown that ThDP-dependent enzymes will often crystallize if the cofactor has been irreversibly inactivated. To explore this possibility, and the utility of inhibitors of phosphonate biosynthesis as potential antibiotics, we synthesized phosphonodifluoropyruvate (PnDFP) as a prospective mechanism-based inhibitor of PnPDC. Here we provide evidence that PnDFP indeed inactivates the enzyme, that the inactivation is irreversible, and is accompanied by release of fluoride ion, i.e., PnDFP bears all the hallmarks of a mechanism-based inhibitor. Unfortunately, the enzyme remains refractive to crystallization.
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Affiliation(s)
| | - Megan P Rogers
- Department of Chemistry and Chemical Biology, Indiana University-Purdue University Indianapolis, Indianapolis, USA
| | - Forest H Andrews
- Department of Chemistry and Chemical Biology, Indiana University-Purdue University Indianapolis, Indianapolis, USA
| | | | - Michael J McLeish
- Department of Chemistry and Chemical Biology, Indiana University-Purdue University Indianapolis, Indianapolis, USA.
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18
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Freestone TS, Ju KS, Wang B, Zhao H. Discovery of a Phosphonoacetic Acid Derived Natural Product by Pathway Refactoring. ACS Synth Biol 2017; 6:217-223. [PMID: 28103011 DOI: 10.1021/acssynbio.6b00299] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The activation of silent natural product gene clusters is a synthetic biology problem of great interest. As the rate at which gene clusters are identified outpaces the discovery rate of new molecules, this unknown chemical space is rapidly growing, as too are the rewards for developing technologies to exploit it. One class of natural products that has been underrepresented is phosphonic acids, which have important medical and agricultural uses. Hundreds of phosphonic acid biosynthetic gene clusters have been identified encoding for unknown molecules. Although methods exist to elicit secondary metabolite gene clusters in native hosts, they require the strain to be amenable to genetic manipulation. One method to circumvent this is pathway refactoring, which we implemented in an effort to discover new phosphonic acids from a gene cluster from Streptomyces sp. strain NRRL F-525. By reengineering this cluster for expression in the production host Streptomyces lividans, utility of refactoring is demonstrated with the isolation of a novel phosphonic acid, O-phosphonoacetic acid serine, and the characterization of its biosynthesis. In addition, a new biosynthetic branch point is identified with a phosphonoacetaldehyde dehydrogenase, which was used to identify additional phosphonic acid gene clusters that share phosphonoacetic acid as an intermediate.
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Affiliation(s)
- Todd S. Freestone
- Department
of Chemical and Biomolecular Engineering, ‡Carl R. Woese Institute for Genomic
Biology, §Departments of Biochemistry, Bioengineering, and Chemistry, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Kou-San Ju
- Department
of Chemical and Biomolecular Engineering, ‡Carl R. Woese Institute for Genomic
Biology, §Departments of Biochemistry, Bioengineering, and Chemistry, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Bin Wang
- Department
of Chemical and Biomolecular Engineering, ‡Carl R. Woese Institute for Genomic
Biology, §Departments of Biochemistry, Bioengineering, and Chemistry, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Huimin Zhao
- Department
of Chemical and Biomolecular Engineering, ‡Carl R. Woese Institute for Genomic
Biology, §Departments of Biochemistry, Bioengineering, and Chemistry, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
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19
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Moutiez M, Belin P, Gondry M. Aminoacyl-tRNA-Utilizing Enzymes in Natural Product Biosynthesis. Chem Rev 2017; 117:5578-5618. [DOI: 10.1021/acs.chemrev.6b00523] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Mireille Moutiez
- Institute for Integrative Biology of the
Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette Cedex, France
| | - Pascal Belin
- Institute for Integrative Biology of the
Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette Cedex, France
| | - Muriel Gondry
- Institute for Integrative Biology of the
Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette Cedex, France
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20
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Phosphinothricin Acetyltransferases Identified Using In Vivo, In Vitro, and Bioinformatic Analyses. Appl Environ Microbiol 2016; 82:7041-7051. [PMID: 27694229 DOI: 10.1128/aem.02604-16] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 09/17/2016] [Indexed: 11/20/2022] Open
Abstract
Acetylation of small molecules is widespread in nature, and in some cases, cells use this process to detoxify harmful chemicals. Streptomyces species utilize a Gcn5 N-acetyltransferase (GNAT), known as Bar, to acetylate and detoxify a self-produced toxin, phosphinothricin (PPT), a glutamate analogue. Bar homologues, such as MddA from Salmonella enterica, acetylate methionine analogues such as methionine sulfoximine (MSX) and methionine sulfone (MSO), but not PPT, even though Bar homologues are annotated as PPT acetyltransferases. S. enterica was used as a heterologous host to determine whether or not putative PPT acetyltransferases from various sources could acetylate PPT, MSX, and MSO. In vitro and in vivo analyses identified substrates acetylated by putative PPT acetyltransferases from Deinococcus radiodurans (DR_1057 and DR_1182) and Geobacillus kaustophilus (GK0593 and GK2920). In vivo, synthesis of DR_1182, GK0593, and GK2920 blocked the inhibitory effects of PPT, MSX, and MSO. In contrast, DR_1057 did not detoxify any of the above substrates. Results of in vitro studies were consistent with the in vivo results. In addition, phylogenetic analyses were used to predict the functionality of annotated PPT acetyltransferases in Burkholderia xenovorans, Bacillus subtilis, Staphylococcus aureus, Acinetobacter baylyi, and Escherichia coli IMPORTANCE: The work reported here provides an example of the use of a heterologous system for the identification of enzyme function. Many members of this superfamily of proteins do not have a known function, or it has been annotated solely on the basis of sequence homology to previously characterized enzymes. The critical role of Gcn5 N-acetyltransferases (GNATs) in the modulation of central metabolic processes, and in controlling metabolic stress, necessitates approaches that can reveal their physiological role. The combination of in vivo, in vitro, and bioinformatics approaches reported here identified GNATs that can acetylate and detoxify phosphinothricin.
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21
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Abstract
Organophosphonic acids are unique as natural products in terms of stability and mimicry. The C-P bond that defines these compounds resists hydrolytic cleavage, while the phosphonyl group is a versatile mimic of transition-states, intermediates, and primary metabolites. This versatility may explain why a variety of organisms have extensively explored the use organophosphonic acids as bioactive secondary metabolites. Several of these compounds, such as fosfomycin and bialaphos, figure prominently in human health and agriculture. The enzyme reactions that create these molecules are an interesting mix of chemistry that has been adopted from primary metabolism as well as those with no chemical precedent. Additionally, the phosphonate moiety represents a source of inorganic phosphate to microorganisms that live in environments that lack this nutrient; thus, unusual enzyme reactions have also evolved to cleave the C-P bond. This review is a comprehensive summary of the occurrence and function of organophosphonic acids natural products along with the mechanisms of the enzymes that synthesize and catabolize these molecules.
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Affiliation(s)
- Geoff P Horsman
- Department of Chemistry and Biochemistry, Wilfrid Laurier University , Waterloo, Ontario N2L 3C5, Canada
| | - David L Zechel
- Department of Chemistry, Queen's University , Kingston, Ontario K7L 3N6, Canada
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22
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Conserved biosynthetic pathways for phosalacine, bialaphos and newly discovered phosphonic acid natural products. J Antibiot (Tokyo) 2015; 69:15-25. [PMID: 26328935 PMCID: PMC4731264 DOI: 10.1038/ja.2015.77] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Revised: 05/14/2015] [Accepted: 06/15/2015] [Indexed: 12/03/2022]
Abstract
Natural products containing phosphonic or phosphinic acid functionalities often display potent biological activities with applications in medicine and agriculture. The herbicide phosphinothricin-tripeptide (PTT) was the first phosphinate natural product discovered, yet despite numerous studies, questions remain surrounding key transformations required for its biosynthesis. In particular, the enzymology required to convert phosphonoformate to carboxyphosphonoenolpyruvate and the mechanisms underlying phosphorus-methylation remain poorly understood. In addition, the model for NRPS assembly of the intact tripeptide product has undergone numerous revisions that have yet to be experimentally tested. To further investigate the biosynthesis of this unusual natural product, we completely sequenced the PTT biosynthetic locus from Streptomyces hygroscopicus and compared it to the orthologous cluster from Streptomyces viridochromogenes. We also sequenced and analysed the closely related phosalacine (PAL) biosynthetic locus from Kitasatospora phosalacinea. Using data drawn from the comparative analysis of the PTT and PAL pathways, we also evaluate three related recently discovered phosphonate biosynthetic loci from Streptomyces sviceus, Streptomyces sp. WM6386 and Frankia alni. Our observations address long-standing biosynthetic questions related to PTT and PAL production and suggest that additional members of this pharmacologically important class await discovery.
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23
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Huang Z, Wang KKA, Lee J, van der Donk WA. Biosynthesis of fosfazinomycin is a convergent process. Chem Sci 2015; 6:1282-1287. [PMID: 25621145 PMCID: PMC4303578 DOI: 10.1039/c4sc03095h] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Fosfazinomycin A is a phosphonate natural product in which the C-terminal carboxylate of a Val-Arg dipeptide is connected to methyl 2-hydroxy-2-phosphono-acetate (Me-HPnA) via a unique hydrazide linkage. We report here that Me-HPnA is generated from phosphonoacetaldehyde (PnAA) in three biosynthetic steps through the combined action of an O-methyltransferase (FzmB) and an α-ketoglutarate (α-KG) dependent non-heme iron dioxygenase (FzmG). Unexpectedly, the latter enzyme is involved in two different steps, oxidation of the PnAA to phosphonoacetic acid as well as hydroxylation of methyl 2-phosphonoacetate. The N-methyltransferase (FzmH) was able to methylate Arg-NHNH2 (3) to give Arg-NHNHMe (4), constituting the second segment of the fosfazinomycin molecule. Methylation of other putative intermediates such as desmethyl fosfazinomycin B was not observed. Collectively, our current data support a convergent biosynthetic pathway to fosfazinomycin.
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Affiliation(s)
- Zedu Huang
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801. ; Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801. ; Howard Hughes Medical Institute, University of Illinois at Urbana-Champaign, Urbana, IL 61801
| | - Kwo-Kwang A Wang
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801. ; Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801. ; Howard Hughes Medical Institute, University of Illinois at Urbana-Champaign, Urbana, IL 61801
| | - Jaeheon Lee
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801
| | - Wilfred A van der Donk
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801. ; Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801. ; Howard Hughes Medical Institute, University of Illinois at Urbana-Champaign, Urbana, IL 61801
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24
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In Salmonella enterica, the Gcn5-related acetyltransferase MddA (formerly YncA) acetylates methionine sulfoximine and methionine sulfone, blocking their toxic effects. J Bacteriol 2014; 197:314-25. [PMID: 25368301 DOI: 10.1128/jb.02311-14] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Protein and small-molecule acylation reactions are widespread in nature. Many of the enzymes catalyzing acylation reactions belong to the Gcn5-related N-acetyltransferase (GNAT; PF00583) family, named after the yeast Gcn5 protein. The genome of Salmonella enterica serovar Typhimurium LT2 encodes 26 GNATs, 11 of which have no known physiological role. Here, we provide in vivo and in vitro evidence for the role of the MddA (methionine derivative detoxifier; formerly YncA) GNAT in the detoxification of oxidized forms of methionine, including methionine sulfoximine (MSX) and methionine sulfone (MSO). MSX and MSO inhibited the growth of an S. enterica ΔmddA strain unless glutamine or methionine was present in the medium. We used an in vitro spectrophotometric assay and mass spectrometry to show that MddA acetylated MSX and MSO. An mddA(+) strain displayed biphasic growth kinetics in the presence of MSX and glutamine. Deletion of two amino acid transporters (GlnHPQ and MetNIQ) in a ΔmddA strain restored growth in the presence of MSX. Notably, MSO was transported by GlnHPQ but not by MetNIQ. In summary, MddA is the mechanism used by S. enterica to respond to oxidized forms of methionine, which MddA detoxifies by acetyl coenzyme A-dependent acetylation.
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25
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Cioni JP, Doroghazi J, Ju KS, Yu X, Evans BS, Lee J, Metcalf WW. Cyanohydrin phosphonate natural product from Streptomyces regensis. JOURNAL OF NATURAL PRODUCTS 2014; 77:243-249. [PMID: 24437999 PMCID: PMC3993929 DOI: 10.1021/np400722m] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Indexed: 06/03/2023]
Abstract
Streptomyces regensis strain WC-3744 was identified as a potential phosphonic acid producer in a large-scale screen of microorganisms for the presence of the pepM gene, which encodes the key phosphonate biosynthetic enzyme phosphoenolpyruvate phosphonomutase. (31)P NMR revealed the presence of several unidentified phosphonates in spent medium after growth of S. regensis. These compounds were purified and structurally characterized via extensive 1D and 2D NMR spectroscopic and mass spectrometric analyses. Three new phosphonic acid metabolites, whose structures were confirmed by comparison to chemically synthesized standards, were observed: (2-acetamidoethyl)phosphonic acid (1), (2-acetamido-1-hydroxyethyl)phosphonic (3), and a novel cyanohydrin-containing phosphonate, (cyano(hydroxy)methyl)phosphonic acid (4). The gene cluster responsible for synthesis of these molecules was also identified from the draft genome sequence of S. regensis, laying the groundwork for future investigations into the metabolic pathway leading to this unusual natural product.
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Affiliation(s)
- Joel P. Cioni
- Department of Microbiology and The Institute for Genomic Biology, University of Illinois, Urbana−Champaign, Illinois 61801, United States
| | - James
R. Doroghazi
- Department of Microbiology and The Institute for Genomic Biology, University of Illinois, Urbana−Champaign, Illinois 61801, United States
| | - Kou-San Ju
- Department of Microbiology and The Institute for Genomic Biology, University of Illinois, Urbana−Champaign, Illinois 61801, United States
| | - Xiaomin Yu
- Department of Microbiology and The Institute for Genomic Biology, University of Illinois, Urbana−Champaign, Illinois 61801, United States
| | - Bradley S. Evans
- Department of Microbiology and The Institute for Genomic Biology, University of Illinois, Urbana−Champaign, Illinois 61801, United States
| | - Jaeheon Lee
- Department of Microbiology and The Institute for Genomic Biology, University of Illinois, Urbana−Champaign, Illinois 61801, United States
| | - William W. Metcalf
- Department of Microbiology and The Institute for Genomic Biology, University of Illinois, Urbana−Champaign, Illinois 61801, United States
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26
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Purification and characterization of phosphonoglycans from Glycomyces sp. strain NRRL B-16210 and Stackebrandtia nassauensis NRRL B-16338. J Bacteriol 2014; 196:1768-79. [PMID: 24584498 DOI: 10.1128/jb.00036-14] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Two related actinomycetes, Glycomyces sp. strain NRRL B-16210 and Stackebrandtia nassauensis NRRL B-16338, were identified as potential phosphonic acid producers by screening for the gene encoding phosphoenolpyruvate (PEP) mutase, which is required for the biosynthesis of most phosphonates. Using a variety of analytical techniques, both strains were subsequently shown to produce phosphonate-containing exopolysaccharides (EPS), also known as phosphonoglycans. The phosphonoglycans were purified by sequential organic solvent extractions, methanol precipitation, and ultrafiltration. The EPS from the Glycomyces strain has a mass of 40 to 50 kDa and is composed of galactose, xylose, and five distinct partially O-methylated galactose residues. Per-deutero-methylation analysis indicated that galactosyl residues in the polysaccharide backbone are 3,4-linked Gal, 2,4-linked 3-MeGal, 2,3-linked Gal, 3,6-linked 2-MeGal, and 4,6-linked 2,3-diMeGal. The EPS from the Stackebrandtia strain is comprised of glucose, galactose, xylose, and four partially O-methylated galactose residues. Isotopic labeling indicated that the O-methyl groups in the Stackebrandtia phosphonoglycan arise from S-adenosylmethionine. The phosphonate moiety in both phosphonoglycans was shown to be 2-hydroxyethylphosphonate (2-HEP) by (31)P nuclear magnetic resonance (NMR) and mass spectrometry following strong acid hydrolysis of the purified molecules. Partial acid hydrolysis of the purified EPS from Glycomyces yielded 2-HEP in ester linkage to the O-5 or O-6 position of a hexose and a 2-HEP mono(2,3-dihydroxypropyl)ester. Partial acid hydrolysis of Stackebrandtia EPS also revealed the presence of 2-HEP mono(2,3-dihydroxypropyl)ester. Examination of the genome sequences of the two strains revealed similar pepM-containing gene clusters that are likely to be required for phosphonoglycan synthesis.
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27
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Gao J, Ju KS, Yu X, Velásquez JE, Mukherjee S, Lee J, Zhao C, Evans BS, Doroghazi JR, Metcalf WW, van der Donk WA. Use of a phosphonate methyltransferase in the identification of the fosfazinomycin biosynthetic gene cluster. Angew Chem Int Ed Engl 2014; 53:1334-7. [PMID: 24376039 PMCID: PMC3927463 DOI: 10.1002/anie.201308363] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Revised: 11/16/2013] [Indexed: 12/19/2022]
Abstract
Natural product discovery has been boosted by genome mining approaches, but compound purification is often still challenging. We report an enzymatic strategy for "stable isotope labeling of phosphonates in extract" (SILPE) that facilitates their purification. We used the phosphonate methyltransferase DhpI involved in dehydrophos biosynthesis to methylate a variety of phosphonate natural products in crude spent medium with a mixture of labeled and unlabeled S-adenosyl methionine. Mass-guided fractionation then allowed straightforward purification. We illustrate its utility by purifying a phosphonate that led to the identification of the fosfazinomycin biosynthetic gene cluster. This unusual natural product contains a hydrazide linker between a carboxylic acid and a phosphonic acid. Bioinformatic analysis of the gene cluster provides insights into how such a structure might be assembled.
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Affiliation(s)
- Jiangtao Gao
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West, Gregory Drive, Urbana, Illinois 61801, USA
| | - Kou-San Ju
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West, Gregory Drive, Urbana, Illinois 61801, USA
| | - Xiaomin Yu
- Department of Microbiology, 601 South Goodwin Avenue, Urbana, Illinois 61801, USA
| | - Juan E. Velásquez
- Howard Hughes Medical Institute and Department of Chemistry, University of Illinois at Urbana-Champaign, 600, South Mathews Avenue, Urbana, Illinois 61801, USA
| | - Subha Mukherjee
- Howard Hughes Medical Institute and Department of Chemistry, University of Illinois at Urbana-Champaign, 600, South Mathews Avenue, Urbana, Illinois 61801, USA
| | - Jaeheon Lee
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West, Gregory Drive, Urbana, Illinois 61801, USA
| | - Changming Zhao
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West, Gregory Drive, Urbana, Illinois 61801, USA
| | - Bradley S. Evans
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West, Gregory Drive, Urbana, Illinois 61801, USA
| | - James R. Doroghazi
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West, Gregory Drive, Urbana, Illinois 61801, USA
| | - William W. Metcalf
- Department of Microbiology, 601 South Goodwin Avenue, Urbana, Illinois 61801, USA
| | - Wilfred A. van der Donk
- Howard Hughes Medical Institute and Department of Chemistry, University of Illinois at Urbana-Champaign, 600, South Mathews Avenue, Urbana, Illinois 61801, USA
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28
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Gao J, Ju KS, Yu X, Velásquez JE, Mukherjee S, Lee J, Zhao C, Evans BS, Doroghazi JR, Metcalf WW, van der Donk WA. Use of a Phosphonate Methyltransferase in the Identification of the Fosfazinomycin Biosynthetic Gene Cluster. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201308363] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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29
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Diversity and abundance of phosphonate biosynthetic genes in nature. Proc Natl Acad Sci U S A 2013; 110:20759-64. [PMID: 24297932 DOI: 10.1073/pnas.1315107110] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Phosphonates, molecules containing direct carbon-phosphorus bonds, compose a structurally diverse class of natural products with interesting and useful biological properties. Although their synthesis in protozoa was discovered more than 50 y ago, the extent and diversity of phosphonate production in nature remains poorly characterized. The rearrangement of phosphoenolpyruvate (PEP) to phosphonopyruvate, catalyzed by the enzyme PEP mutase (PepM), is shared by the vast majority of known phosphonate biosynthetic pathways. Thus, the pepM gene can be used as a molecular marker to examine the occurrence and abundance of phosphonate-producing organisms. Based on the presence of this gene, phosphonate biosynthesis is common in microbes, with ~5% of sequenced bacterial genomes and 7% of genome equivalents in metagenomic datasets carrying pepM homologs. Similarly, we detected the pepM gene in ~5% of random actinomycete isolates. The pepM-containing gene neighborhoods from 25 of these isolates were cloned, sequenced, and compared with those found in sequenced genomes. PEP mutase sequence conservation is strongly correlated with conservation of other nearby genes, suggesting that the diversity of phosphonate biosynthetic pathways can be predicted by examining PEP mutase diversity. We used this approach to estimate the range of phosphonate biosynthetic pathways in nature, revealing dozens of discrete groups in pepM amplicons from local soils, whereas hundreds were observed in metagenomic datasets. Collectively, our analyses show that phosphonate biosynthesis is both diverse and relatively common in nature, suggesting that the role of phosphonate molecules in the biosphere may be more important than is often recognized.
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30
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Peck SC, van der Donk WA. Phosphonate biosynthesis and catabolism: a treasure trove of unusual enzymology. Curr Opin Chem Biol 2013; 17:580-8. [PMID: 23870698 DOI: 10.1016/j.cbpa.2013.06.018] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Revised: 06/15/2013] [Accepted: 06/17/2013] [Indexed: 11/25/2022]
Abstract
Natural product biosynthesis has proven a fertile ground for the discovery of novel chemistry. Herein we review the progress made in elucidating the biosynthetic pathways of phosphonate and phosphinate natural products such as the antibacterial compounds dehydrophos and fosfomycin, the herbicidal phosphinothricin-containing peptides, and the antimalarial compound FR-900098. In each case, investigation of the pathway has yielded unusual, and often unprecedented, biochemistry. Likewise, recent investigations have uncovered novel ways to cleave the CP bond to yield phosphate under phosphorus starvation conditions. These include the discovery of novel oxidative cleavage of the CP bond catalyzed by PhnY and PhnZ as well as phosphonohydrolases that liberate phosphate from phosphonoacetate. Perhaps the crown jewel of phosphonate catabolism has been the recent resolution of the longstanding problem of the C-P lyase responsible for reductively cleaving the CP bond of a number of different phosphonates to release phosphate. Taken together, the strides made on both metabolic and catabolic fronts illustrate an array of fascinating biochemistry.
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Affiliation(s)
- Spencer C Peck
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, IL 61801, USA
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31
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Revisiting the biosynthesis of dehydrophos reveals a tRNA-dependent pathway. Proc Natl Acad Sci U S A 2013; 110:10952-7. [PMID: 23776232 DOI: 10.1073/pnas.1303568110] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Bioactive natural products containing a C-P bond act as mimics of phosphate esters and carboxylic acids, thereby competing with these compounds for active sites of enzymes. Dehydrophos (DHP), a broad-spectrum antibiotic, is a phosphonotripeptide produced by Streptomyces luridus, in which glycine and leucine are linked to an aminophosphonate analog of dehydroalanine, ΔAla(P). This unique feature, in combination with the monomethylation of the phosphonic acid, renders DHP a Trojan horse type antibiotic because peptidase-mediated hydrolysis will release methyl acetylphosphonate, a potent inhibitor of pyruvate dehydrogenase. Bioinformatic analysis of the biosynthetic gene cluster suggested that ΔAla(P) would be generated from Ser(P), the phosphonate analog of Ser, by phosphorylation and subsequent elimination, and that ΔAla(P) would be condensed with Leu-tRNA(Leu). DhpH was anticipated to carry out this elimination/ligation cascade. DhpH is a multidomain protein, in which a pyridoxal phosphate binding domain is fused to an N-acetyltransferase domain related to the general control nonderepressible-5 (GCN5) family. In this work, the activity of DhpH was reconstituted in vitro. The enzyme was able to catalyze the β-elimination reaction of pSer(P) to generate ΔAla(P), but it was unable to condense ΔAla(P) with Leu. Instead, ΔAla(P) is hydrolyzed to acetyl phosphonate, which is converted to Ala(P) by a second pyridoxal phosphate-dependent enzyme, DhpD. Ala(P) is the substrate for the condensation with Leu-tRNA(Leu) catalyzed by the C-terminal domain of DhpH. DhpJ, a 2-oxoglutarate/Fe(II)-dependent enzyme, introduces the vinyl functionality into Leu-Ala(P) acting as a desaturase, and addition of Gly by DhpK in a Gly-tRNA(Gly)-dependent manner completes the in vitro biosynthesis of dehydrophos.
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32
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Metcalf WW, Griffin BM, Cicchillo RM, Gao J, Janga SC, Cooke HA, Circello BT, Evans BS, Martens-Habbena W, Stahl DA, van der Donk WA. Synthesis of methylphosphonic acid by marine microbes: a source for methane in the aerobic ocean. Science 2012; 337:1104-7. [PMID: 22936780 DOI: 10.1126/science.1219875] [Citation(s) in RCA: 155] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Relative to the atmosphere, much of the aerobic ocean is supersaturated with methane; however, the source of this important greenhouse gas remains enigmatic. Catabolism of methylphosphonic acid by phosphorus-starved marine microbes, with concomitant release of methane, has been suggested to explain this phenomenon, yet methylphosphonate is not a known natural product, nor has it been detected in natural systems. Further, its synthesis from known natural products would require unknown biochemistry. Here we show that the marine archaeon Nitrosopumilus maritimus encodes a pathway for methylphosphonate biosynthesis and that it produces cell-associated methylphosphonate esters. The abundance of a key gene in this pathway in metagenomic data sets suggests that methylphosphonate biosynthesis is relatively common in marine microbes, providing a plausible explanation for the methane paradox.
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Affiliation(s)
- William W Metcalf
- Institute for Genomic Biology, University of Illinois, Urbana, IL 61801, USA.
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33
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McSorley FR, Wyatt PB, Martinez A, DeLong EF, Hove-Jensen B, Zechel DL. PhnY and PhnZ Comprise a New Oxidative Pathway for Enzymatic Cleavage of a Carbon–Phosphorus Bond. J Am Chem Soc 2012; 134:8364-7. [DOI: 10.1021/ja302072f] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Fern R. McSorley
- Department of Chemistry, Queen’s University, 90 Bader Lane, Kingston,
Ontario, Canada K7L 3N6
| | - Peter B. Wyatt
- School
of Biological and Chemical
Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, U.K
| | - Asuncion Martinez
- Division of Biological Engineering,
Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge,
Massachusetts 02139, United States
| | - Edward F. DeLong
- Division of Biological Engineering,
Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge,
Massachusetts 02139, United States
| | - Bjarne Hove-Jensen
- Department of Chemistry, Queen’s University, 90 Bader Lane, Kingston,
Ontario, Canada K7L 3N6
| | - David L. Zechel
- Department of Chemistry, Queen’s University, 90 Bader Lane, Kingston,
Ontario, Canada K7L 3N6
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34
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Villarreal-Chiu JF, Quinn JP, McGrath JW. The genes and enzymes of phosphonate metabolism by bacteria, and their distribution in the marine environment. Front Microbiol 2012; 3:19. [PMID: 22303297 PMCID: PMC3266647 DOI: 10.3389/fmicb.2012.00019] [Citation(s) in RCA: 128] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Accepted: 01/10/2012] [Indexed: 11/13/2022] Open
Abstract
Phosphonates are compounds that contain the chemically stable carbon–phosphorus (C–P) bond. They are widely distributed amongst more primitive life forms including many marine invertebrates and constitute a significant component of the dissolved organic phosphorus reservoir in the oceans. Virtually all biogenic C–P compounds are synthesized by a pathway in which the key step is the intramolecular rearrangement of phosphoenolpyruvate to phosphonopyruvate. However C–P bond cleavage by degradative microorganisms is catalyzed by a number of enzymes – C–P lyases, C–P hydrolases, and others of as-yet-uncharacterized mechanism. Expression of some of the pathways of phosphonate catabolism is controlled by ambient levels of inorganic P (Pi) but for others it is Pi-independent. In this report we review the enzymology of C–P bond metabolism in bacteria, and also present the results of an in silico investigation of the distribution of the genes that encode the pathways responsible, in both bacterial genomes and in marine metagenomic libraries, and their likely modes of regulation. Interrogation of currently available whole-genome bacterial sequences indicates that some 10% contain genes encoding putative pathways of phosphonate biosynthesis while ∼40% encode one or more pathways of phosphonate catabolism. Analysis of metagenomic data from the global ocean survey suggests that some 10 and 30%, respectively, of bacterial genomes across the sites sampled encode these pathways. Catabolic routes involving phosphonoacetate hydrolase, C–P lyase(s), and an uncharacterized 2-aminoethylphosphonate degradative sequence were predominant, and it is likely that both substrate-inducible and Pi-repressible mechanisms are involved in their regulation. The data we present indicate the likely importance of phosphonate-P in global biogeochemical P cycling, and by extension its role in marine productivity and in carbon and nitrogen dynamics in the oceans.
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35
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Abstract
The P-C bonds in phosphonate and phosphinate natural products endow them with a high level of stability and the ability to mimic phosphate esters and carboxylates. As such, they have a diverse range of enzyme targets that act on substrates containing such functionalities. Recent years have seen a renewed interest in discovery efforts focused on this class of compounds as well as in understanding their biosynthetic pathways. This chapter focuses on current knowledge of these biosynthetic pathways as well as tools for phosphonate discovery.
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36
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DeSieno MA, van der Donk WA, Zhao H. Characterization and application of the Fe(II) and α-ketoglutarate dependent hydroxylase FrbJ. Chem Commun (Camb) 2011; 47:10025-7. [PMID: 21829824 DOI: 10.1039/c1cc13597j] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The Fe(II) and α-ketoglutarate-dependent hydroxylase FrbJ was previously demonstrated to utilize FR-900098 synthesizing a second phosphonate FR-33289. Here we assessed its ability to hydroxylate other possible substrates, generating a library of potential antimalarial compounds. Through a series of bioassays and in vitro experiments, we identified two new antimalarials.
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Affiliation(s)
- Matthew A DeSieno
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, 600 S. Mathews Avenue, Urbana, IL 61801, USA
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37
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The antibiotic dehydrophos is converted to a toxic pyruvate analog by peptide bond cleavage in Salmonella enterica. Antimicrob Agents Chemother 2011; 55:3357-62. [PMID: 21537024 DOI: 10.1128/aac.01483-10] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The metabolic processing of dehydrophos, a broad-spectrum peptide antibiotic containing an unusual vinyl-phosphonate moiety, was examined by using a panel of Salmonella enterica mutants deficient in peptide uptake and catabolism. Dehydrophos bioactivity is lost in opp tpp double mutants, demonstrating a requirement for uptake via nonspecific oligopeptide permeases. Dehydrophos bioactivity is also abolished in a quadruple Salmonella mutant lacking the genes encoding peptidases A, B, D, and N, showing that hydrolysis of the peptide bond is required for activity. (31)P nuclear magnetic resonance spectroscopy was used to assess the fate of dehydrophos following in vitro digestion of the antibiotic with purified PepA. The results suggest that the initial product of peptidase processing is 1-aminovinyl-phosphonate O-methyl ester. This phosphonate analogue of dehydroalanine undergoes rearrangement to the more stable imine, followed by spontaneous hydrolysis to yield O-methyl-acetylphosphonate, a structural analogue of pyruvate. This compound is a known inhibitor of pyruvate dehydrogenase and pyruvate oxidase and is probably the active species responsible for dehydrophos bioactivity.
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38
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Nair SK, van der Donk WA. Structure and mechanism of enzymes involved in biosynthesis and breakdown of the phosphonates fosfomycin, dehydrophos, and phosphinothricin. Arch Biochem Biophys 2011; 505:13-21. [PMID: 20854789 PMCID: PMC3040005 DOI: 10.1016/j.abb.2010.09.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2010] [Revised: 09/11/2010] [Accepted: 09/14/2010] [Indexed: 11/28/2022]
Abstract
Recent years have seen a rapid increase in the mechanistic and structural information on enzymes that are involved in the biosynthesis and breakdown of naturally occurring phosphonates. This review focuses on these recent developments with an emphasis on those enzymes that have been characterized crystallographically in the past five years, including proteins involved in the biosynthesis of phosphinothricin, fosfomycin, and dehydrophos and proteins involved in resistance mechanisms.
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Affiliation(s)
- Satish K Nair
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, IL 61801, USA
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39
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Characterization and structure of DhpI, a phosphonate O-methyltransferase involved in dehydrophos biosynthesis. Proc Natl Acad Sci U S A 2010; 107:17557-62. [PMID: 20876132 DOI: 10.1073/pnas.1006848107] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Phosphonate natural products possess a range of biological activities as a consequence of their ability to mimic phosphate esters or tetrahedral intermediates formed in enzymatic reactions involved in carboxyl group metabolism. The dianionic form of these compounds at pH 7 poses a drawback with respect to their ability to mimic carboxylates and tetrahedral intermediates. Microorganisms producing phosphonates have evolved two solutions to overcome this hurdle: biosynthesis of monoanionic phosphinates containing two P-C bonds or esterification of the phosphonate group. The latter solution was first discovered for the antibiotic dehydrophos that contains a methyl ester of a phosphonodehydroalanine group. We report here the expression, purification, substrate scope, and structure of the O-methyltransferase from the dehydrophos biosynthetic gene cluster. The enzyme utilizes S-adenosylmethionine to methylate a variety of phosphonates including 1-hydroxyethylphosphonate, 1,2-dihydroxyethylphosphonate, and acetyl-1-aminoethylphosphonate. Kinetic analysis showed that the best substrates are tripeptides containing as C-terminal residue a phosphonate analog of alanine suggesting the enzyme acts late in the biosynthesis of dehydrophos. These conclusions are corroborated by the X-ray structure that reveals an active site that can accommodate a tripeptide substrate. Furthermore, the structural studies demonstrate a conformational change brought about by substrate or product binding. Interestingly, the enzyme has low substrate specificity and was used to methylate the clinical antibiotic fosfomycin and the antimalaria clinical candidate fosmidomycin, showing its promise for applications in bioengineering.
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40
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Kuemin M, van der Donk WA. Structure-activity relationships of the phosphonate antibiotic dehydrophos. Chem Commun (Camb) 2010; 46:7694-6. [PMID: 20871915 DOI: 10.1039/c0cc02958k] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Synthetic derivatives of the phosphonate antibiotic dehydrophos were tested for antimicrobial activity. Both the phosphonate monomethyl ester and the vinyl phosphonate moiety proved to be important for bacteriocidal activity of the natural product.
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Affiliation(s)
- Michael Kuemin
- Department of Chemistry and Howard Hughes Medical Institute, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave., Urbana, IL 61801, USA
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