scholarly journals Structural and Functional Characterization of Three Polyketide Synthase Gene Clusters in Bacillus amyloliquefaciens FZB 42

2006 ◽  
Vol 188 (11) ◽  
pp. 4024-4036 ◽  
Author(s):  
Xiao-Hua Chen ◽  
Joachim Vater ◽  
Jörn Piel ◽  
Peter Franke ◽  
Romy Scholz ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Bacillus Amyloliquefaciens ◽  
Polyketide Synthase ◽  
Functional Characterization ◽  
Gene Clusters ◽  
Ionization Mass ◽  
Bioactive Natural Products ◽  
Flight Mass Spectrometry ◽  
Polyketide Synthase Gene ◽  
Bacterial Sources

ABSTRACT Although bacterial polyketides are of considerable biomedical interest, the molecular biology of polyketide biosynthesis in Bacillus spp., one of the richest bacterial sources of bioactive natural products, remains largely unexplored. Here we assign for the first time complete polyketide synthase (PKS) gene clusters to Bacillus antibiotics. Three giant modular PKS systems of the trans-acyltransferase type were identified in Bacillus amyloliquefaciens FZB 42. One of them, pks1, is an ortholog of the pksX operon with a previously unknown function in the sequenced model strain Bacillus subtilis 168, while the pks2 and pks3 clusters are novel gene clusters. Cassette mutagenesis combined with advanced mass spectrometric techniques such as matrix-assisted laser desorption ionization-time of flight mass spectrometry and liquid chromatography-electrospray ionization mass spectrometry revealed that the pks1 (bae) and pks3 (dif) gene clusters encode the biosynthesis of the polyene antibiotics bacillaene and difficidin or oxydifficidin, respectively. In addition, B. subtilis OKB105 (pheA sfp 0), a transformant of the B. subtilis 168 derivative JH642, was shown to produce bacillaene, demonstrating that the pksX gene cluster directs the synthesis of that polyketide.

scholarly journals The Fusarium verticillioides FUM Gene Cluster Encodes a Zn(II)2Cys6 Protein That Affects FUM Gene Expression and Fumonisin Production

2007 ◽  
Vol 6 (7) ◽  
pp. 1210-1218 ◽  
Author(s):  
Daren W. Brown ◽  
Robert A. E. Butchko ◽  
Mark Busman ◽  
Robert H. Proctor
Keyword(s):  
Gene Cluster ◽  
Polyketide Synthase ◽  
Fusarium Verticillioides ◽  
Gene Clusters ◽  
Biosynthetic Gene Cluster ◽  
Regulatory Proteins ◽  
Wild Type ◽  
Polyketide Synthase Gene ◽  
Splice Forms ◽  
Self Protection

ABSTRACT Fumonisins are mycotoxins produced by some Fusarium species and can contaminate maize or maize products. Ingestion of fumonisins is associated with diseases, including cancer and neural tube defects, in humans and animals. In fungi, genes involved in the synthesis of mycotoxins and other secondary metabolites are often located adjacent to each other in gene clusters. Such genes can encode structural enzymes, regulatory proteins, and/or proteins that provide self-protection. The fumonisin biosynthetic gene cluster includes 16 genes, none of which appear to play a role in regulation. In this study, we identified a previously undescribed gene (FUM21) located adjacent to the fumonisin polyketide synthase gene, FUM1. The presence of a Zn(II)2Cys6 DNA-binding domain in the predicted protein suggested that FUM21 was involved in transcriptional regulation. FUM21 deletion (Δfum21) mutants produce little to no fumonisin in cracked maize cultures but some FUM1 and FUM8 transcripts in a liquid GYAM medium. Complementation of a Δfum21 mutant with a wild-type copy of the gene restored fumonisin production. Analysis of FUM21 cDNAs identified four alternative splice forms (ASFs), and microarray analysis indicated the ASFs were differentially expressed. Based on these data, we present a model for how FUM21 ASFs may regulate fumonisin biosynthesis.

scholarly journals Polyketide Synthase Gene Expression in Relation to Chloromonilicin and Melanin Production in Monilinia fructicola

2020 ◽  
Vol 110 (8) ◽  
pp. 1465-1475
Author(s):  
Fang-Yi Yu ◽  
Chiu-Min Chiu ◽  
Yue-Zhi Lee ◽  
Shiow-Ju Lee ◽  
Chien-Ming Chou ◽  
...  
Keyword(s):  
Gene Expression ◽  
Mass Spectrometry ◽  
Osmotic Stress ◽  
Gene Family ◽  
Polyketide Synthase ◽  
Biologically Active ◽  
Proton Nuclear Magnetic Resonance ◽  
Antifungal Compound ◽  
Ionization Mass ◽  
Monilinia Fructicola

Monilinia fructicola is a fungal pathogen of worldwide significance that causes brown rot of stone fruits. There are only few reports related to the production of biologically active polyketides by this pathogen. In this study, we examined an atypical M. fructicola strain TW5-4 that shows strong antimicrobial activity against various plant pathogens. TW5-4 also displays sparse growth in culture, low virulence, and higher levels of melanin compared with its albino mutant, TW5-4WM, and a wild-type strain Mf13-81. Antifungal compounds were extracted from TW5-4 and purified by thin-layer chromatography following visualization with an on-the-chromatogram inhibition assay. The principal antifungal compound was identified by linear ion trap mass spectrometry, high-resolution electro-spray ionization mass spectrometry, and proton nuclear magnetic resonance analyses as the polyketide chloromonilicin. Multiple M. fructicola polyketide synthase (PKS) sequences were then cloned by degenerate PCR and inverse PCR. Sequence analyses support presence of a 10-member PKS gene family in the M. fructicola genome. Analyses of PKS gene expression found no strong correlation between chloromonilicin production in culture and transcript levels of any of the PKS gene family members in mycelium of strains TW5-4, TW5-4WM, and Mf13-81. However, MfPKS12, a homolog of BcPKS12 involved in biosynthesis of 1,8-dihydroxynaphthalene (DHN)-melanin in Botrytis cinerea, was strongly expressed in mycelia of TW5-4 and Mf13-81. An MfPKS12-silenced mutant accumulated significantly less melanin in mycelia, had lower resistance to polyethylene glycol-induced osmotic stress, and displayed reduced virulence on nectarine fruit. The results suggest that DHN-melanin is required for tolerance to osmotic stress and full virulence in M. fructicola.

scholarly journals Non-methane organic gas emissions from biomass burning: identification, quantification, and emission factors from PTR-ToF during the FIREX 2016 laboratory experiment

2018 ◽  
Vol 18 (5) ◽  
pp. 3299-3319 ◽  
Author(s):  
Abigail R. Koss ◽  
Kanako Sekimoto ◽  
Jessica B. Gilman ◽  
Vanessa Selimovic ◽  
Matthew M. Coggon ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Biomass Burning ◽  
Chemical Ionization ◽  
Proton Transfer Reaction ◽  
Emission Factors ◽  
Ionization Mass ◽  
Extensive Literature ◽  
Oxygenated Compounds ◽  
Flight Mass Spectrometry ◽  
Organic Gases

Abstract. Volatile and intermediate-volatility non-methane organic gases (NMOGs) released from biomass burning were measured during laboratory-simulated wildfires by proton-transfer-reaction time-of-flight mass spectrometry (PTR-ToF). We identified NMOG contributors to more than 150 PTR ion masses using gas chromatography (GC) pre-separation with electron ionization, H3O+ chemical ionization, and NO+ chemical ionization, an extensive literature review, and time series correlation, providing higher certainty for ion identifications than has been previously available. Our interpretation of the PTR-ToF mass spectrum accounts for nearly 90 % of NMOG mass detected by PTR-ToF across all fuel types. The relative contributions of different NMOGs to individual exact ion masses are mostly similar across many fires and fuel types. The PTR-ToF measurements are compared to corresponding measurements from open-path Fourier transform infrared spectroscopy (OP-FTIR), broadband cavity-enhanced spectroscopy (ACES), and iodide ion chemical ionization mass spectrometry (I− CIMS) where possible. The majority of comparisons have slopes near 1 and values of the linear correlation coefficient, R2, of > 0.8, including compounds that are not frequently reported by PTR-MS such as ammonia, hydrogen cyanide (HCN), nitrous acid (HONO), and propene. The exceptions include methylglyoxal and compounds that are known to be difficult to measure with one or more of the deployed instruments. The fire-integrated emission ratios to CO and emission factors of NMOGs from 18 fuel types are provided. Finally, we provide an overview of the chemical characteristics of detected species. Non-aromatic oxygenated compounds are the most abundant. Furans and aromatics, while less abundant, comprise a large portion of the OH reactivity. The OH reactivity, its major contributors, and the volatility distribution of emissions can change considerably over the course of a fire.

scholarly journals Genome-based survey of nonribosomal peptide synthetase and polyketide synthase gene clusters in type strains of the genus Microtetraspora

2016 ◽  
Vol 69 (9) ◽  
pp. 712-718 ◽  
Author(s):  
Hisayuki Komaki ◽  
Natsuko Ichikawa ◽  
Tomohiko Tamura ◽  
Akio Oguchi ◽  
Moriyuki Hamada ◽  
...  
Keyword(s):  
Polyketide Synthase ◽  
Gene Clusters ◽  
Nonribosomal Peptide Synthetase ◽  
Nonribosomal Peptide ◽  
Peptide Synthetase ◽  
Polyketide Synthase Gene ◽  
Type Strains

Functional characterization of a veA-dependent polyketide synthase gene in Aspergillus flavus necessary for the synthesis of asparasone, a sclerotium-specific pigment

2014 ◽  
Vol 64 ◽  
pp. 25-35 ◽  
Author(s):  
Jeffrey W. Cary ◽  
Pamela Y. Harris-Coward ◽  
Kenneth C. Ehrlich ◽  
José Diana Di Mavungu ◽  
Svetlana V. Malysheva ◽  
...  
Keyword(s):  
Aspergillus Flavus ◽  
Polyketide Synthase ◽  
Functional Characterization ◽  
Polyketide Synthase Gene
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