-
Proceedings of the National Academy of... Sep 2023Animal cytoplasmic fatty acid synthase (FAS) represents a unique family of enzymes that are classically thought to be most closely related to fungal polyketide synthase...
Animal cytoplasmic fatty acid synthase (FAS) represents a unique family of enzymes that are classically thought to be most closely related to fungal polyketide synthase (PKS). Recently, a widespread family of animal lipid metabolic enzymes has been described that bridges the gap between these two ubiquitous and important enzyme classes: the animal FAS-like PKSs (AFPKs). Although very similar in sequence to FAS enzymes that produce saturated lipids widely found in animals, AFPKs instead produce structurally diverse compounds that resemble bioactive polyketides. Little is known about the factors that bridge lipid and polyketide synthesis in the animals. Here, we describe the function of EcPKS2 from , which synthesizes a complex polypropionate natural product found in this mollusc. EcPKS2 starter unit promiscuity potentially explains the high diversity of polyketides found in and among molluscan species. Biochemical comparison of EcPKS2 with the previously described EcPKS1 reveals molecular principles governing substrate selectivity that should apply to related enzymes encoded within the genomes of photosynthetic gastropods. Hybridization experiments combining EcPKS1 and EcPKS2 demonstrate the interactions between the ketoreductase and ketosynthase domains in governing the product outcomes. Overall, these findings enable an understanding of the molecular principles of structural diversity underlying the many molluscan polyketides likely produced by the diverse AFPK enzyme family.
Topics: Animals; Polyketide Synthases; Fatty Acid Synthases; Biological Products; Gastropoda; Polyketides; Lipids
PubMed: 37695909
DOI: 10.1073/pnas.2305575120 -
Complete Reconstitution and Deorphanization of the 3 MDa Nocardiosis-Associated Polyketide Synthase.Journal of the American Chemical Society Apr 2020Several strains associated with nocardiosis, a potentially life-threatening disease, house a nonamodular assembly line polyketide synthase (PKS) that presumably...
Several strains associated with nocardiosis, a potentially life-threatening disease, house a nonamodular assembly line polyketide synthase (PKS) that presumably synthesizes an unknown polyketide. Here, we report the discovery and structure elucidation of the NOCAP (nocardiosis-associated polyketide) aglycone by first fully reconstituting the NOCAP synthase from purified protein components followed by heterologous expression in and spectroscopic analysis of the purified products. The NOCAP aglycone has an unprecedented structure comprised of a substituted resorcylaldehyde headgroup linked to a 15-carbon tail that harbors two conjugated all- trienes separated by a stereogenic hydroxyl group. This report is the first example of reconstituting a -acyltransferase assembly line PKS and of using these approaches to "deorphanize" a complete assembly line PKS identified via genomic sequencing. With the NOCAP aglycone in hand, the stage is set for understanding how this PKS and associated tailoring enzymes confer an advantage to their native hosts during human infections.
Topics: Bacterial Proteins; Humans; Multigene Family; Nocardia; Nocardia Infections; Polyketide Synthases; Polyketides
PubMed: 32182063
DOI: 10.1021/jacs.0c00904 -
International Journal of Molecular... May 2023Polyketides are a diverse set of natural products with versatile applications as pharmaceuticals, nutraceuticals, and cosmetics, to name a few. Of several types of... (Review)
Review
Polyketides are a diverse set of natural products with versatile applications as pharmaceuticals, nutraceuticals, and cosmetics, to name a few. Of several types of polyketides, aromatic polyketides comprising type II and III polyketides contain many chemicals important for human health such as antibiotics and anticancer agents. Most aromatic polyketides are produced from soil bacteria or plants, which are difficult to engineer and grow slowly in industrial settings. To this end, metabolic engineering and synthetic biology have been employed to efficiently engineer heterologous model microorganisms for enhanced production of important aromatic polyketides. In this review, we discuss the recent advancement in metabolic engineering and synthetic biology strategies for the production of type II and type III polyketides in model microorganisms. Future challenges and prospects of aromatic polyketide biosynthesis by synthetic biology and enzyme engineering approaches are also discussed.
Topics: Humans; Polyketides; Metabolic Engineering; Synthetic Biology; Polyketide Synthases; Biological Products
PubMed: 37240269
DOI: 10.3390/ijms24108923 -
Nature Communications Mar 2023Assembly-line polyketide synthases (PKSs) are molecular factories that produce diverse metabolites with wide-ranging biological activities. PKSs usually work by...
Assembly-line polyketide synthases (PKSs) are molecular factories that produce diverse metabolites with wide-ranging biological activities. PKSs usually work by constructing and modifying the polyketide backbone successively. Here, we present the cryo-EM structure of CalA3, a chain release PKS module without an ACP domain, and its structures with amidation or hydrolysis products. The domain organization reveals a unique "∞"-shaped dimeric architecture with five connected domains. The catalytic region tightly contacts the structural region, resulting in two stabilized chambers with nearly perfect symmetry while the N-terminal docking domain is flexible. The structures of the ketosynthase (KS) domain illustrate how the conserved key residues that canonically catalyze C-C bond formation can be tweaked to mediate C-N bond formation, revealing the engineering adaptability of assembly-line polyketide synthases for the production of novel pharmaceutical agents.
Topics: Polyketide Synthases; Catalytic Domain
PubMed: 36899013
DOI: 10.1038/s41467-023-36989-w -
Applied Microbiology and Biotechnology Nov 2022The fungus Trichoderma arundinaceum exhibits biological control activity against crop diseases caused by other fungi. Two mechanisms that likely contribute to this...
The fungus Trichoderma arundinaceum exhibits biological control activity against crop diseases caused by other fungi. Two mechanisms that likely contribute to this activity are upregulation of plant defenses and production of two types of antifungal secondary metabolites: the sesquiterpenoid harzianum A (HA) and the polyketide-derived aspinolides. The goal of the current study was to identify aspinolide biosynthetic genes as part of an effort to understand how these metabolites contribute to the biological control activity of T. arundinaceum. Comparative genomics identified two polyketide synthase genes (asp1 and asp2) that occur in T. arundinaceum and Aspergillus ochraceus, which also produces aspinolides. Gene deletion and biochemical analyses in T. arundinaceum indicated that both genes are required for aspinolide production: asp2 for formation of a 10-member lactone ring and asp1 for formation of a butenoyl subsituent at position 8 of the lactone ring. Gene expression and comparative genomics analyses indicated that asp1 and asp2 are located within a gene cluster that occurs in both T. arundinaceum and A. ochraceus. A survey of genome sequences representing 35 phylogenetically diverse Trichoderma species revealed that intact homologs of the cluster occurred in only two other species, which also produced aspinolides. An asp2 mutant inhibited fungal growth more than the wild type, but an asp1 mutant did not, and the greater inhibition by the asp2 mutant coincided with increased HA production. These findings indicate that asp1 and asp2 are aspinolide biosynthetic genes and that loss of either aspinolide or HA production in T. arundinaceum can be accompanied by increased production of the other metabolite(s). KEY POINTS: • Two polyketide synthase genes are required for aspinolide biosynthesis. • Blocking aspinolide production increases production of the terpenoid harzianum A. • Aspinolides and harzianum A act redundantly in antibiosis of T. arundinaceum.
Topics: Polyketide Synthases; Gene Expression Regulation, Fungal; Antifungal Agents; Trichoderma; Terpenes; Sesquiterpenes; Lactones; Polyketides
PubMed: 36166052
DOI: 10.1007/s00253-022-12182-9 -
Journal of Natural Medicines Sep 2023Agarwood has been valued as an exquisite, high-grade fragrant wood since ancient times. Due to the scarcity of high-quality agarwood, it is quite expensive, and the... (Review)
Review
Agarwood has been valued as an exquisite, high-grade fragrant wood since ancient times. Due to the scarcity of high-quality agarwood, it is quite expensive, and the number of original plants has been drastically reduced due to overharvesting, including illegal logging. Despite this, a reliable method of agarwood cultivation has yet to be developed. Thus, identifying the biosynthetic pathways of the fragrant components in agarwood might help developers to optimize the culture conditions and create artificial agarwood, by monitoring the expression of the biosynthetic enzymes or their genes. This review presents the characteristics of our recently identified key enzyme, 2-(2-phenylethyl)chromone precursor synthase (PECPS), which generates the common precursor of 2-(2-phenylethyl)chromones (PECs), the main fragrances in agarwood, as well as our reasoning to reach these conclusions. We also discuss the biosynthetic pathway of PECs, unveiled following the identification of PECPS.
Topics: Polyketide Synthases; Chromones; Flavonoids; Wood
PubMed: 37597060
DOI: 10.1007/s11418-023-01743-5 -
Science (New York, N.Y.) Nov 2021Type I modular polyketide synthases are homodimeric multidomain assembly line enzymes that synthesize a variety of polyketide natural products by performing polyketide...
Type I modular polyketide synthases are homodimeric multidomain assembly line enzymes that synthesize a variety of polyketide natural products by performing polyketide chain extension and β-keto group modification reactions. We determined the 2.4-angstrom-resolution x-ray crystal structure and the 3.1-angstrom-resolution cryo–electron microscopy structure of the Lsd14 polyketide synthase, stalled at the transacylation and condensation steps, respectively. These structures revealed how the constituent domains are positioned relative to each other, how they rearrange depending on the step in the reaction cycle, and the specific interactions formed between the domains. Like the evolutionarily related mammalian fatty acid synthase, Lsd14 contains two reaction chambers, but only one chamber in Lsd14 has the full complement of catalytic domains, indicating that only one chamber produces the polyketide product at any given time.
Topics: Acyl Carrier Protein; Acylation; Acyltransferases; Catalytic Domain; Cryoelectron Microscopy; Crystallography, X-Ray; Hydro-Lyases; Lasalocid; Models, Molecular; Polyketide Synthases; Protein Conformation; Protein Domains; Protein Multimerization; Streptomyces
PubMed: 34735234
DOI: 10.1126/science.abi8532 -
Molecules (Basel, Switzerland) Mar 2023The hard-to-culture slightly halophilic myxobacterium "" SMH-27-4 produces antifungal cyclodepsipeptide miuraenamide A (). Herein, the region (85.9 kbp) containing the...
The hard-to-culture slightly halophilic myxobacterium "" SMH-27-4 produces antifungal cyclodepsipeptide miuraenamide A (). Herein, the region (85.9 kbp) containing the biosynthetic gene cluster (BGC) coding the assembly of was identified and heterologously expressed in A biosynthetic pathway proposed using in silico analysis was verified through the gene disruption of the heterologous transformant. In addition to the core polyketide synthase (PKS) and nonribosomal peptide synthase (NRPS) genes, tyrosine halogenase and -methyltransferase genes participated in the biosynthesis of as their gene-disrupted mutants produced a new congener, debromomiuraenamide A (), and a previously isolated congener, miuraenamide E (), respectively. Multigene disruption provided a heterologous mutant that produced with the highest yield among the prepared mutants. When fed on 3-bromo-L-tyrosine, this mutant produced more in the yield of 1.21 mg/L, which was 20 times higher than that produced by the initially prepared heterologous transformant. Although this yield was comparable to that of the original producer SMH-27-4 (1 mg/L), the culture time was 4.5 times shorter than that of SMH-27-4, indicating a five-fold efficiency in productivity. The results indicate the great potential of the miuraenamide BGC for the future contribution to drug development through logical gene manipulation.
Topics: Anti-Bacterial Agents; Myxococcales; Depsipeptides; Polyketide Synthases; Multigene Family
PubMed: 36985787
DOI: 10.3390/molecules28062815 -
Natural Product Reports Oct 2014In this viewpoint highlights are drawn from a deep analysis of the multifaceted problem of aflatoxin biosynthesis, one of the most highly rearranged polyketide natural... (Review)
Review
In this viewpoint highlights are drawn from a deep analysis of the multifaceted problem of aflatoxin biosynthesis, one of the most highly rearranged polyketide natural products known. Fundamental chemical insights have emerged into how cytochrome P450-mediated skeletal rearrangements occur through probable cationic intermediates and oxidative dearomatizations, which are applicable more widely in natural product catabolism. So to where current experimental methods have failed in our hands, bioinformatic tools and fresh experimental strategies have been developed to identify linker regions in large, polydomain proteins and guide the dissection and reassembly of their component parts. It has been possible to deduce individual catalytic roles, how overall synthesis is coordinated and how these enzymes can be re-engineered in a rational manner to prepare non-natural products. These insights and innovations were often not planned or anticipated, but sprung from the inability to answer fundamental questions. Advances in science can take place by chance favoring the prepared mind, other times by refusing to give up and devising new solutions to address hard questions. Both ways forward played important roles in the investigation of aflatoxin biosynthesis. For these contributions I am pleased to share this special issue of NPR with John Vederas and Tom Simpson, who have been leaders in this field for the last third of a century.
Topics: Aflatoxins; Molecular Structure; Polyketide Synthases; Polyketides
PubMed: 25079257
DOI: 10.1039/c4np00092g -
Advanced Science (Weinheim,... Jun 2024Pigments such as anthraquinones (AQs) and melanins are antioxidants, protectants, or virulence factors. AQs from the entomopathogenic bacterium Photorhabdus laumondii...
Pigments such as anthraquinones (AQs) and melanins are antioxidants, protectants, or virulence factors. AQs from the entomopathogenic bacterium Photorhabdus laumondii are produced by a modular type II polyketide synthase system. A key enzyme involved in AQ biosynthesis is PlAntI, which catalyzes the hydrolysis of the bicyclic-intermediate-loaded acyl carrier protein, polyketide trimming, and assembly of the aromatic AQ scaffold. Here, multiple crystal structures of PlAntI in various conformations and with bound substrate surrogates or inhibitors are reported. Structure-based mutagenesis and activity assays provide experimental insights into the three sequential reaction steps to yield the natural product AQ-256. For comparison, a series of ligand-complex structures of two functionally related hydrolases involved in the biosynthesis of 1,8-dihydroxynaphthalene-melanin in pathogenic fungi is determined. These data provide fundamental insights into the mechanism of polyketide trimming that shapes pigments in pro- and eukaryotes.
Topics: Anthraquinones; Polyketides; Melanins; Polyketide Synthases; Photorhabdus; Naphthols; Pigments, Biological
PubMed: 38491909
DOI: 10.1002/advs.202400184