scholarly journals In vitro reconstitution of α-pyrone ring formation in myxopyronin biosynthesis

2015 ◽  
Vol 6 (8) ◽  
pp. 5076-5085 ◽  
Author(s):  
H. Sucipto ◽  
J. H. Sahner ◽  
E. Prusov ◽  
S. C. Wenzel ◽  
R. W. Hartmann ◽  
...  
Keyword(s):  
Natural Products ◽  
Polyketide Synthase ◽  
Ring Formation ◽  
Type I ◽  
Pyrone Ring ◽  
In Vitro Reconstitution

α-Pyrone rings exist in many polyketide synthase (PKS) derived natural products. We report the first in vitro reconstitution of α-pyrone ring formation by a type I PKS using chemically synthesized substrates.

scholarly journals Biosynthesis of Hexahydroxyperylenequinone Melanin via Oxidative Aryl Coupling by Cytochrome P-450 in Streptomyces griseus

2005 ◽  
Vol 187 (23) ◽  
pp. 8149-8155 ◽  
Author(s):  
Nobutaka Funa ◽  
Masanori Funabashi ◽  
Yasuo Ohnishi ◽  
Sueharu Horinouchi
Keyword(s):  
Polyketide Synthase ◽  
Uv Light ◽  
Streptomyces Griseus ◽  
Type I ◽  
Type Iii Polyketide Synthase ◽  
Melanin Biosynthesis ◽  
Type Iii ◽  
In Vitro Reconstitution ◽  
Cytochrome P 450

ABSTRACT Dihydroxyphenylalanine (DOPA) melanins formed from tyrosine by tyrosinases are found in microorganisms, plants, and animals. Most species in the soil-dwelling, gram-positive bacterial genus Streptomyces produce DOPA melanins and melanogenesis is one of the characteristics used for taxonomy. Here we report a novel melanin biosynthetic pathway involving a type III polyketide synthase (PKS), RppA, and a cytochrome P-450 enzyme, P-450mel, in Streptomyces griseus. In vitro reconstitution of the P-450mel catalyst with spinach ferredoxin-NADP+ reductase/ferredoxin revealed that it catalyzed oxidative biaryl coupling of 1,3,6,8-tetrahydroxynaphthalene (THN), which was formed from five molecules of malonyl-coenzyme A by the action of RppA to yield 1,4,6,7,9,12-hexahydroxyperylene-3,10-quinone (HPQ). HPQ readily autopolymerized to generate HPQ melanin. Disruption of either the chromosomal rppA or P-450mel gene resulted in abolishment of the HPQ melanin synthesis in S. griseus and a decrease in the resistance of spores to UV-light irradiation. These findings show that THN-derived melanins are not exclusive in eukaryotic fungal genera but an analogous pathway is conserved in prokaryotic streptomycete species as well. A vivid contrast in THN melanin biosynthesis between streptomycetes and fungi is that the THN synthesized by the action of a type III PKS is used directly for condensation in the former, while the THN synthesized by the action of type I PKSs is first reduced and the resultant 1,8-dihydroxynaphthalene is then condensed in the latter.

In vitro reconstitution of the biosynthetic pathway of 3-hydroxypicolinic acid

2019 ◽  
Vol 17 (3) ◽  
pp. 454-460 ◽  
Author(s):  
Xuan Yun ◽  
Qian Zhang ◽  
Meinan Lv ◽  
Hai Deng ◽  
Zixin Deng ◽  
...  
Keyword(s):  
Natural Products ◽  
Building Block ◽  
Biosynthetic Pathway ◽  
In Vitro Reconstitution ◽  
Important Building Block

Four enzymes direct the biosynthesis of 3-hydroxypicolinic acid, an important building block of bacterial natural products.

scholarly journals Biosynthesis Gene Cluster and Oxazole Ring Formation Enzyme for Inthomycins in Streptomyces sp. Strain SYP-A7193

2020 ◽  
Vol 86 (20) ◽  
Author(s):  
Shao-Yang Hou ◽  
Meng-Yue Zhang ◽  
Hong-Da Wang ◽  
Yi-Xuan Zhang
Keyword(s):  
Gene Cluster ◽  
Genome Sequencing ◽  
Gene Disruption ◽  
Polyketide Synthase ◽  
Nonribosomal Peptide Synthetase ◽  
Ring Formation ◽  
Type I ◽  
Oxazole Ring ◽  
Peptide Synthetase ◽  
Biosynthesis Gene

ABSTRACT Inthomycins belong to a growing family of oxazole-containing polyketides and exhibit a broad spectrum of anti-oomycete and herbicidal activities. In this study, we purified inthomycins A and B from the metabolites of Streptomyces sp. strain SYP-A7193 and determined their chemical structures. Genome sequencing, comparative genomic analysis, and gene disruption of Streptomyces sp. SYP-A7193 showed that the inthomycin biosynthetic gene cluster (itm) belonged to the hybrid polyketide synthase (PKS)/nonribosomal peptide synthetase (NRPS) system. Functional domain comparison and disruption/complementation experiments of itm12 resulted in the complete loss of inthomycins A and B and the subsequent restoration of their production, confirming that itm12 encodes a discrete acyltransferase (AT), and hence, itm was considered to belong to the trans-AT type I PKS system. Moreover, the disruption/complementation experiments of itm15 also resulted in the loss and restoration of inthomycin A and B formation. Further gene cloning, expression, purification, and activity verification of itm15 revealed that Itm15 is a cyclodehydratase that catalyzes a straight-chain dehydration reaction to form an oxazole ring for the biosynthesis of inthomycins A and B. Thus, we discovered a novel enzyme that catalyzes oxazole ring formation and elucidated the complete biosynthetic pathway of inthomycins. IMPORTANCE Streptomyces species produce numerous secondary metabolites with diverse structures and pharmacological activities that are beneficial for human health and have several applications in agriculture. In this study, hybrid nonribosomal peptide synthetase/polyketide synthase metabolites inthomycins A and B were isolated from after fermenting Streptomyces sp. SYP-A7193. Genome sequencing, gene disruption, gene complementation, heterologous expression, and activity assay revealed that the biosynthesis gene assembly line of inthomycins A and B was a 95.3-kb trans-AT type I PKS system in the strain SYP-A7193. More importantly, Itm15, a cyclodehydratase, was identified to be an oxazole ring formation enzyme required for the biosynthesis of inthomycins A and B; it is significant to discover this catalyzation reaction in the PKS/NRPS system in the field of microbiology. Our findings could provide further insights into the diversity of trans-AT type I PKS systems and the mechanism of oxazole cyclization involved in the biosynthesis of natural products.

scholarly journals Expanding the Fluorine Chemistry of Living Systems Using Engineered Polyketide Synthase Pathways

Science ◽  
2013 ◽  
Vol 341 (6150) ◽  
pp. 1089-1094 ◽  
Author(s):  
Mark C. Walker ◽  
Benjamin W. Thuronyi ◽  
Louise K. Charkoudian ◽  
Brian Lowry ◽  
Chaitan Khosla ◽  
...  
Keyword(s):  
Natural Products ◽  
Synthetic Biology ◽  
Natural Product ◽  
Polyketide Synthase ◽  
Building Blocks ◽  
Living Systems ◽  
Synthetic Compounds ◽  
Fluorinated Building Blocks

Organofluorines represent a rapidly expanding proportion of molecules that are used in pharmaceuticals, diagnostics, agrochemicals, and materials. Despite the prevalence of fluorine in synthetic compounds, the known biological scope is limited to a single pathway that produces fluoroacetate. Here, we demonstrate that this pathway can be exploited as a source of fluorinated building blocks for introduction of fluorine into natural-product scaffolds. Specifically, we have constructed pathways involving two polyketide synthase systems, and we show that fluoroacetate can be used to incorporate fluorine into the polyketide backbone in vitro. We further show that fluorine can be inserted site-selectively and introduced into polyketide products in vivo. These results highlight the prospects for the production of complex fluorinated natural products using synthetic biology.

scholarly journals Partial In Vitro Reconstitution of an Orphan Polyketide Synthase Associated with Clinical Cases of Nocardiosis

2016 ◽  
Vol 11 (9) ◽  
pp. 2636-2641 ◽  
Author(s):  
James Kuo ◽  
Stephen R. Lynch ◽  
Corey W. Liu ◽  
Xirui Xiao ◽  
Chaitan Khosla
Keyword(s):  
Polyketide Synthase ◽  
In Vitro Reconstitution ◽  
Clinical Cases

scholarly journals A bacterial symbiont protects honey bees from fungal disease

2020 ◽  
Author(s):  
Delaney L. Miller ◽  
Eric A. Smith ◽  
Irene L. G. Newton
Keyword(s):  
Honey Bee ◽  
Fungal Pathogens ◽  
Polyketide Synthase ◽  
Opportunistic Infections ◽  
Gene Clusters ◽  
Type I ◽  
Plant Host ◽  
Colony Losses

Fungi are the leading cause of insect disease, contributing to the decline of wild and managed populations1,2. For ecologically and economically critical species, such as the European honey bee (Apis mellifera), the presence and prevalence of fungal pathogens can have far reaching consequences, endangering other species and threatening food security3,4,5. Our ability to address fungal epidemics and opportunistic infections is currently hampered by the limited number of antifungal therapies6,7. Novel antifungal treatments are frequently of bacterial origin and produced by defensive symbionts (bacteria that associate with an animal/plant host and protect against natural enemies 89. Here we examined the capacity of a honey bee-associated bacterium, Bombella apis, to suppress the growth of fungal pathogens and ultimately protect bee brood (larvae and pupae) from infection. Our results showed that strains of B. apis inhibit the growth of two insect fungal pathogens, Beauveria bassiana and Aspergillus flavus, in vitro. This phenotype was recapitulated in vivo; bee brood supplemented with B. apis were significantly less likely to be infected by A. flavus. Additionally, the presence of B. apis reduced sporulation of A. flavus in the few bees that were infected. Analyses of biosynthetic gene clusters across B. apis strains suggest antifungal production via a Type I polyketide synthase. Secreted metabolites from B. apis alone were sufficient to suppress fungal growth, supporting this hypothesis. Together, these data suggest that B. apis protects bee brood from fungal infection by the secretion of an antifungal metabolite. On the basis of this discovery, new antifungal treatments could be developed to mitigate honey bee colony losses, and, in the future, could address fungal epidemics in other species.

scholarly journals Complete Genome Sequence of Amycolatopsis sp. CA-230715, Encoding a 35-Module Type I Polyketide Synthase

2021 ◽  
Vol 10 (38) ◽  
Author(s):  
Tue S. Jørgensen ◽  
Tetiana Gren ◽  
Daniel Oves-Costales ◽  
Francisco Javier Ortiz-López ◽  
Daniel Carretero-Molina ◽  
...  
Keyword(s):  
Natural Products ◽  
Genome Sequence ◽  
Complete Genome Sequence ◽  
Complete Genome ◽  
Polyketide Synthase ◽  
Type I ◽  
Module Type

We report the sequencing, assembly, and annotation of the genome of Amycolatopsis sp. strain CA-230715, a potentially interesting producer of natural products. The genome of CA-230715 was sequenced using PacBio, Illumina, and Nanopore technologies. It consists of a circular 10,363,158-nucleotide (nt) chromosome and a circular 12,080-nt plasmid.

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