scholarly journals Aromatic polyketide biosynthesis: fidelity, evolution and engineering

2019 ◽  
Author(s):  
Zhiwei Qin ◽  
Rebecca Devine ◽  
Matthew I. Hutchings ◽  
Barrie Wilkinson
Keyword(s):  
Biosynthetic Pathway ◽  
Polyketide Synthase ◽  
Single Gene ◽  
Biosynthetic Gene Cluster ◽  
Type Ii ◽  
Trace Level ◽  
Aromatic Polyketides ◽  
Pyridine Moiety ◽  
Catalytic Role ◽  
New Compounds

AbstractWe report the formicapyridines which are structurally and biosynthetically related to the pentacyclic fasamycin and formicamycin aromatic polyketides but comprise a rare pyridine moiety. These new compounds are trace level metabolites formed by derailment of the major biosynthetic pathway. Inspired by evolutionary logic we show that rational mutation of a single gene in the biosynthetic gene cluster leads to a significant increase both in total formicapyridine production and their enrichment relative to the fasamycins/formicamycins. Our observations broaden the polyketide biosynthetic landscape and identify a non-catalytic role for ABM superfamily proteins in type II polyketide synthase assemblages for maintaining biosynthetic pathway fidelity.

scholarly journals Engineered Biosynthesis of a Novel Amidated Polyketide, Using the Malonamyl-Specific Initiation Module from the Oxytetracycline Polyketide Synthase

2006 ◽  
Vol 72 (4) ◽  
pp. 2573-2580 ◽  
Author(s):  
Wenjun Zhang ◽  
Brian D. Ames ◽  
Shiou-Chuan Tsai ◽  
Yi Tang
Keyword(s):  
Polyketide Synthase ◽  
Major Product ◽  
Polyketide Synthases ◽  
Type Ii ◽  
Streptomyces Rimosus ◽  
Aromatic Polyketides ◽  
Starter Unit ◽  
Necessary And Sufficient ◽  
Bacterial Type

ABSTRACT Tetracyclines are aromatic polyketides biosynthesized by bacterial type II polyketide synthases (PKSs). Understanding the biochemistry of tetracycline PKSs is an important step toward the rational and combinatorial manipulation of tetracycline biosynthesis. To this end, we have sequenced the gene cluster of oxytetracycline (oxy and otc genes) PKS genes from Streptomyces rimosus. Sequence analysis revealed a total of 21 genes between the otrA and otrB resistance genes. We hypothesized that an amidotransferase, OxyD, synthesizes the malonamate starter unit that is a universal building block for tetracycline compounds. In vivo reconstitution using strain CH999 revealed that the minimal PKS and OxyD are necessary and sufficient for the biosynthesis of amidated polyketides. A novel alkaloid (WJ35, or compound 2) was synthesized as the major product when the oxy-encoded minimal PKS, the C-9 ketoreductase (OxyJ), and OxyD were coexpressed in CH999. WJ35 is an isoquinolone compound derived from an amidated decaketide backbone and cyclized with novel regioselectivity. The expression of OxyD with a heterologous minimal PKS did not afford similarly amidated polyketides, suggesting that the oxy-encoded minimal PKS possesses novel starter unit specificity.

scholarly journals Organization of the biosynthetic gene cluster for the macrolide concanamycin A in Streptomyces neyagawaensis ATCC 27449

Microbiology ◽  
2005 ◽  
Vol 151 (10) ◽  
pp. 3161-3169 ◽  
Author(s):  
Stephen F. Haydock ◽  
Anthony N. Appleyard ◽  
Tatiana Mironenko ◽  
John Lester ◽  
Natasha Scott ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Biosynthetic Pathway ◽  
Polyketide Synthase ◽  
Building Blocks ◽  
Biosynthetic Gene Cluster ◽  
Sequence Motif ◽  
Biosynthetic Gene ◽  
Concanamycin A ◽  
Modular Polyketide Synthase

The macrolide antibiotic concanamycin A has been identified as an exceptionally potent inhibitor of the vacuolar (V-type) ATPase. Such compounds have been mooted as the basis of a potential drug treatment for osteoporosis, since the V-ATPase is involved in the osteoclast-mediated bone resorption that underlies this common condition. To enable combinatorial engineering of altered concanamycins, the biosynthetic gene cluster governing the biosynthesis of concanamycin A has been cloned from Streptomyces neyagawaensis and shown to span a region of over 100 kbp of contiguous DNA. An efficient transformation system has been developed for S. neyagawaensis and used to demonstrate the role of the cloned locus in the formation of concanamycin A. Sequence analysis of the 28 ORFs in the region has revealed key features of the biosynthetic pathway, in particular the biosynthetic origin of portions of the backbone, which arise from the unusual polyketide building blocks ethylmalonyl-CoA and methoxymalonyl-ACP, and the origin of the pendant deoxysugar moiety 4′-O-carbamoyl-2′-deoxyrhamnose, as well as the presence of a modular polyketide synthase (PKS) encoded by six giant ORFs. Examination of the methoxymalonyl-specific acyltransferase (AT) domains has led to recognition of an amino acid sequence motif which can be used to distinguish methylmalonyl-CoA- from methoxymalonyl-ACP-specific AT domains in natural PKSs.

scholarly journals Biosynthesis of Mycotoxin Fusaric Acid and Application of a PLP-Dependent Enzyme for Chemoenzymatic Synthesis of Substituted L-Pipecolic Acids

2020 ◽  
Author(s):  
Yang Hai ◽  
Mengbin Chen ◽  
Arthur Huang ◽  
Yi Tang
Keyword(s):  
Biosynthetic Pathway ◽  
Polyketide Synthase ◽  
Picolinic Acid ◽  
Fusaric Acid ◽  
Biosynthetic Gene Cluster ◽  
Chemoenzymatic Synthesis ◽  
Flavin Mononucleotide ◽  
Biosynthetic Gene ◽  
Bond Forming ◽  
Peptide Synthetase

<div><p>Fusaric acid (FA) is a well-known mycotoxin that plays an important role in plant pathology. The biosynthetic gene cluster for FA has been identified but the biosynthetic pathway remains unclarified. Here, we elucidated the biosynthesis of FA, which features a two-enzyme catalytic cascade, a pyridoxal 5’-phosphate (PLP)-dependent enzyme (Fub7) and a flavin mononucleotide (FMN)-dependent oxidase (Fub9) in synthesizing the picolinic acid scaffold. FA biosynthesis also involves an off-line collaboration between a highly reducing polyketide synthase (HRPKS, Fub1) and a nonribosomal peptide synthetase (NRPS)-like carboxylic acid reductase (Fub8) in making an aliphatic alpha,beta-unsaturated aldehyde. By harnessing the stereoselective C-C bond forming activity of Fub7, we established a chemoenzymatic route for stereoconvergent synthesis of a series of 5-alkyl, 5,5-dialkyl, and 5,5,6-trialkyl-L-pipecolic acids of high diastereomeric ratio. </p></div>

scholarly journals Biosynthesis of Mycotoxin Fusaric Acid and Application of a PLP-Dependent Enzyme for Chemoenzymatic Synthesis of Substituted L-Pipecolic Acids

2020 ◽  
Author(s):  
Yang Hai ◽  
Mengbin Chen ◽  
Arthur Huang ◽  
Yi Tang
Keyword(s):  
Biosynthetic Pathway ◽  
Polyketide Synthase ◽  
Picolinic Acid ◽  
Fusaric Acid ◽  
Biosynthetic Gene Cluster ◽  
Chemoenzymatic Synthesis ◽  
Flavin Mononucleotide ◽  
Biosynthetic Gene ◽  
Bond Forming ◽  
Peptide Synthetase

<div><p>Fusaric acid (FA) is a well-known mycotoxin that plays an important role in plant pathology. The biosynthetic gene cluster for FA has been identified but the biosynthetic pathway remains unclarified. Here, we elucidated the biosynthesis of FA, which features a two-enzyme catalytic cascade, a pyridoxal 5’-phosphate (PLP)-dependent enzyme (Fub7) and a flavin mononucleotide (FMN)-dependent oxidase (Fub9) in synthesizing the picolinic acid scaffold. FA biosynthesis also involves an off-line collaboration between a highly reducing polyketide synthase (HRPKS, Fub1) and a nonribosomal peptide synthetase (NRPS)-like carboxylic acid reductase (Fub8) in making an aliphatic alpha,beta-unsaturated aldehyde. By harnessing the stereoselective C-C bond forming activity of Fub7, we established a chemoenzymatic route for stereoconvergent synthesis of a series of 5-alkyl, 5,5-dialkyl, and 5,5,6-trialkyl-L-pipecolic acids of high diastereomeric ratio. </p></div>

scholarly journals An Unconventional Melanin Biosynthetic Pathway in Ustilago maydis

2019 ◽  
Author(s):  
Esmeralda Z. Reyes-Fernández ◽  
Yi-Ming Shi ◽  
Peter Grün ◽  
Helge B. Bode ◽  
Michael Bölker
Keyword(s):  
Biosynthetic Pathway ◽  
Polyketide Synthase ◽  
Model Organism ◽  
Ustilago Maydis ◽  
Biosynthetic Gene Cluster ◽  
Polyketide Synthases ◽  
Phytopathogenic Fungus ◽  
P450 Monooxygenase ◽  
Intermediate Products ◽  
Corn Smut

ABSTRACTUstilago maydis is a phytopathogenic fungus responsible for corn smut disease. Although it is a very well established model organism for the study of plant-microbe interactions, its biosynthetic potential has not been totally explored. By analyzing U. maydis genome, we identified a biosynthetic gene cluster whose activation led to the production of a black melanin pigment. Single deletion mutants of the cluster genes revealed that five encoded enzymes are required for the accumulation of the black pigment, including three polyketide synthases (pks3, pks4 and pks5), a cytochrome P450 monooxygenase (cyp4) and a protein with similarity to versicolorin B-synthase (vbs1). Moreover, metabolic profiles of the mutants defective for pks3 and pks4 indicated that the products of these genes catalyze together the first step in the melanin biosynthetic pathway since none of the mutants accumulated any melanin or intermediate products. Mutants deleted for pks5 produced orsellinic acid (OA) and triacetic acid lactone (TAL), suggesting that both products are produced by Pks3 and Pks4. It might thus demonstrate that Pks5 plays a role in a reaction downstream of that catalyzed by Pks3 and Pks4. OA and TAL were also found in extracts of a cyp4 deletion mutant along with several heterodimers of TAL and Pks5-derived orsellinic aldehyde compounds. According to their phenotypes and the intermediate products isolated from these strains, Cyp4 and Vbs1 seem to be involved in reactions downstream of Pks5. Our findings suggest that U. maydis synthesizes a new melanin based on coumarin and pyran-2-one intermediates, while most fungal melanins are derived from 1,8-dihydroxynaphthalene (DHN) or L-3,4-dihydroxyphenylalanine (L-DOPA). Along with these observations, this work also provides an insight into the mechanisms of polyketide synthases in this filamentous fungus.IMPORTANCEUstilago maydis represents one of the major threats for maize plants since it is responsible for corn smut disease, which generates considerable economical losses around the world. Therefore, contributing to a better understanding of the biochemistry of defense mechanisms used by U. maydis to protect itself against harsh environments, as the synthesis of melanin, could provide improved biological tools for tackling the problem and protect the crops. In addition, the fact that this fungus synthesizes melanin in a very unique way, requiring more than one polyketide synthase for producing this secondary metabolite, gives a different perspective on the complexity of these multimodular enzymes and their evolution in the fungal kingdom.

scholarly journals 4-vinylpyridine derivatives: Protonation, methylation and silver(I) coordination chemistry

2021 ◽  
pp. 174751982198965
Author(s):  
Guoqi Zhang
Keyword(s):  
Mass Spectrometry ◽  
Schiff Base ◽  
Coordination Chemistry ◽  
Elemental Analysis ◽  
Silver Complex ◽  
Spectroscopic Techniques ◽  
X Ray ◽  
X Ray Crystallography ◽  
Pyridine Moiety ◽  
New Compounds

( E)-4-[2-(Pyridin-4-yl)vinyl]benzaldehyde, containing both a 4-vinylpyridine and an aldehyde functionality, is utilized to develop new, highly conjugated chalcone compounds and a bis-Schiff base azine compound. The chalcone-containing compounds are further explored for their protonation, methylation and silver(I) coordination chemistry using the pyridine moiety. In parallel, a cyano-containing analogue, ( E)-4-[2-(pyridin-4-yl)vinyl]benzonitrile is also synthesized and studied for its silver(I) coordination chemistry. These new compounds are fully characterized by mass spectrometry, elemental analysis and spectroscopic techniques. The methylated product of ( E)-1-(9-anthryl)-3-{4-[2-(pyridin-4-yl)vinyl]phenyl}prop-2-en-1-one and a silver complex of ( E)-4-[2-(pyridin-4-yl)vinyl]benzonitrile are structurally determined by X-ray crystallography.

Isolation of a chitinase overproducing mutant of Streptomyces peucetius defective in daunorubicin biosynthesis

2000 ◽  
Vol 46 (10) ◽  
pp. 956-960 ◽  
Author(s):  
Kuzhandhaivel S Vetrivel ◽  
Kuppamuthu Dharmalingam
Keyword(s):  
Biosynthetic Pathway ◽  
Time Course ◽  
Polyketide Synthase ◽  
Protein Profile ◽  
Restriction Enzymes ◽  
Wild Type ◽  
Anthracycline Antibiotic ◽  
Streptomyces Peucetius ◽  
Chitinase Production ◽  
Major Alteration

Streptomyces peucetius, producer of the antitumor anthracycline antibiotic daunorubicin, was mutagenized, and mutants defective in daunorubicin biosynthesis were screened. One mutant (SPVI), which failed to produce daunorubicin, was found to overproduce an extracellular chitinase. Time course analyses of chitinase production and of the extracellular protein profile showed that the increase in activity is due to increased synthesis of the enzyme protein. The production of chitinase in SPVI was repressed by glucose as in the case of wild-type S. peucetius. PFGE analysis of VspI restriction fragments of S. peucetius and SPVI showed that there was no major alteration in the mutant genome. The hybridization pattern of S. peucetius and SPVI genomic DNA digested with various restriction enzymes was identical when probed with dnrUVJI genes of the S. peucetius daunorubicin cluster and chiA of Streptomyces lividans 66. The possible step affected in the daunorubicin biosynthetic pathway could be a polyketide synthase, since aklanonic acid, the earliest detectable intermediate in the daunorubicin pathway, was not synthesized in SPVI.Key words: Streptomyces peucetius, chitinase, daunorubicin, NTG mutagenesis.

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