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polyketide synthase

Outi Nivala, Greta Faccio, Mikko Arvas, Perttu Permi, Johanna Buchert, Kristiina Kruus, Maija-Liisa Mattinen
BACKGROUND: Despite of the presence of sulfhydryl oxidases (SOXs) in the secretomes of industrially relevant organisms and their many potential applications, only few of these enzymes have been biochemically characterized. In addition, basic functions of most of the SOX enzymes reported so far are not fully understood. In particular, the physiological role of secreted fungal SOXs is unclear. RESULTS: The recently identified SOX from Aspergillus tubingensis (AtSOX) was produced, purified and characterized in the present work...
December 8, 2017: BMC Biochemistry
Charles Stewart, Kate Woods, Greg Macias, Andrew C Allan, Roger P Hellens, Joseph P Noel
Biphenyl synthase and benzophenone synthase constitute an evolutionarily distinct clade of type III polyketide synthases (PKSs) that use benzoic acid-derived substrates to produce defense metabolites in plants. The use of benzoyl-CoA as an endogenous substrate is unusual for type III PKSs. Moreover, sequence analyses indicate that the residues responsible for the functional diversification of type III PKSs are mutated in benzoic acid-specific type III PKSs. In order to gain a better understanding of structure-function relationships within the type III PKS family, the crystal structures of biphenyl synthase from Malus × domestica and benzophenone synthase from Hypericum androsaemum were compared with the structure of an archetypal type III PKS: chalcone synthase from Malus × domestica...
December 1, 2017: Acta Crystallographica. Section D, Structural Biology
Adi Lavy, Ray Keren, Ke Yu, Brian C Thomas, Lisa Alvarez-Cohen, Jillian F Banfield, Micha Ilan
Sponges are benthic filter feeders that play pivotal roles in coupling benthic-pelagic processes in the oceans that involve transformation of dissolved and particulate organic carbon and nitrogen into biomass. While the contribution of sponge holobionts to the nitrogen cycle has been recognized in past years, their importance in the sulfur cycle, both oceanic and physiological, has only recently gained attention. Sponges in general, and Theonella swinhoei in particular, harbor a multitude of associated microorganisms that could affect sulfur cycling within the holobiont...
December 1, 2017: Environmental Microbiology
Neil A Holmes, Rebecca Devine, Zhiwei Qin, Ryan F Seipke, Barrie Wilkinson, Matthew I Hutchings
Here we report the complete genome of the new species Streptomyces formicae KY5 isolated from Tetraponera fungus growing ants. S. formicae was sequenced using the PacBio and 454 platforms to generate a single linear chromosome with terminal inverted repeats. Illumina MiSeq sequencing was used to correct base changes resulting from the high error rate associated with PacBio. The genome is 9.6 Mbps, has a GC content of 71.38% and contains 8162 protein coding sequences. Predictive analysis shows this strain encodes at least 45 gene clusters for the biosynthesis of secondary metabolites, including a type 2 polyketide synthase encoding cluster for the antibacterial formicamycins...
November 27, 2017: Journal of Biotechnology
Philip A Storm, Craig A Townsend
Polyketide synthases (PKSs) have several known editing mechanisms to ensure that non-productive intermediates are removed from the acyl carrier protein (ACP). We demonstrate that CitA, a putative hydrolase in the citrinin biosynthetic gene cluster, removes ACP-bound acyl intermediates. We propose that it serves an editing role in trans.
November 30, 2017: Chemical Communications: Chem Comm
Xiaomei Li, Xingkang Wu, Jing Zhu, Yuemao Shen
Ten new pentangular polyphenols, namely amexanthomycins A-J (1-10) were isolated from the strain Amycolatopsis mediterranei S699∆rifA constructed by deleting the polyketide synthase genes responsible for the biosynthesis of rifamycins. Their structures were elucidated on the basis of 1D and 2D NMR spectroscopic data and high-resolution ESIMS. Amexanthomycins A-C (1-3) showed inhibitory activity against human DNA topoisomerases.
November 27, 2017: Applied Microbiology and Biotechnology
Juan Lopera, Ian J Miller, Kerry L McPhail, Jason C Kwan
A symbiotic lifestyle frequently results in genome reduction in bacteria; the isolation of small populations promotes genetic drift and the fixation of deletions and deleterious mutations over time. Transitions in lifestyle, including host restriction or adaptation to an intracellular habitat, are thought to precipitate a wave of sequence degradation events and consequent proliferation of pseudogenes. We describe here a verrucomicrobial symbiont of the tunicate Lissoclinum sp. that appears to be undergoing such a transition, with low coding density and many identifiable pseudogenes...
November 2017: MSystems
Xi Xie, Dauenpen Meesapyodsuk, Xiao Qiu
Thraustochytrium sp. 26185, a unicellular marine protist, synthesizes docosahexaenoic acid, an omega-3 very long chain polyunsaturated fatty acid (VLC-PUFAs), by a polyunsaturated fatty acid (PUFA) synthase comprising three large subunits with multiple catalytic dehydratase (DH) domains critical for introducing double bonds at the specific position of fatty acids. To investigate functions of these DH domains, one DH domain from subunit-A and two DH domains from subunit-C of the PUFA synthase were dissected and expressed as stand-alone enzymes in Escherichia coli...
November 25, 2017: Applied Microbiology and Biotechnology
Jing Huang, NanQing Liao, HaoMing Li
Monacolin K, an inhibitor of HMG-CoA reductase, is a secondary metabolite synthesized by polyketide synthases (PKS) from Monascus ruber. The mokH gene encoding Zn(II)2Cys6 binding protein and mokA gene encoding polyketide synthase are presumed to activate monacolin K production. In this study, linoleic acid could be a quorum sensing signaling molecule to increase monacolin K production in the cyclic AMP(cAMP)-protein kinase A(PKA) signaling pathway. Analysis of the PKA activity and the cAMP concentration shows that linoleic acid could increase cAMP concentration and activate PKA...
November 18, 2017: International Journal of Biological Macromolecules
David R Jackson, Gaurav Shakya, Avinash B Patel, Lina Y Mohammed, Kostas Vasilakis, Pakorn Wattana-Amorn, Timothy R Valentic, Jacob Milligan, Matthew P Crump, John Crosby, Shiou-Chuan Tsai
Daunorubicin is a type II polyketide, one of a large class of polyaromatic natural products with anticancer, antibiotic and antiviral activity. Type II polyketides are formed by the assembly of malonyl-CoA building blocks, though in rare cases, biosynthesis is initiated by the incorporation of a non-malonyl derived starter unit, which adds molecular diversity to the poly-β-ketone backbone. Priming mechanisms for the transfer of novel starter units onto polyketide synthases (PKS) are still poorly understood...
November 21, 2017: ACS Chemical Biology
Christian Reuter, Mona Alzheimer, Heike Walles, Tobias A Oelschlaeger
The human gastrointestinal tract is a complex ecosystem in which epithelial cells and microorganisms of the intestinal microbiota live in symbiosis. Certain members of the microbiota, in particular Escherichia coli strains of the B2 phylotype, carry the polyketide synthase (pks)-island encoding the genotoxin colibactin. Colibactin is a non-ribosomal peptide (NRP) or polyketide (PK)-NRP hybrid of still unsolved structure, which induces DNA double strand breaks (DSBs) in eukaryotic cells. However, direct contact between live bacteria and host cell is required in order to elicit these genotoxic effects...
November 20, 2017: Cellular Microbiology
Erik Mingyar, Renata Novakova, Renata Knirschova, Lubomira Feckova, Carmen Bekeova, Jan Kormanec
We previously identified the aur1 gene cluster, responsible for the production of the angucycline antibiotic auricin in Streptomyces aureofaciens CCM 3239. Pulse-field gel electrophoresis showed a single, 241kb linear plasmid, pSA3239, in this strain, and several approaches confirmed the presence of the aur1 cluster in this plasmid. We report here the nucleotide sequence of this 241,076-bp plasmid. pSA3239 contains an unprecedentedly small (13bp) telomeric sequence CCCGCGGAGCGGG, which is identical to the conserved Palindrome I sequence involved in the priming of end-patching replication...
November 16, 2017: Gene
Anu Humisto, Jouni Jokela, Liwei Liu, Matti Wahlsten, Hao Wang, Perttu Permi, João Paulo Machado, Agostinho Antunes, David P Fewer, Kaarina Sivonen
Swinholides are 42-carbon ring polyketides with a twofold axis of symmetry. They are potent cytotoxins that disrupt the actin cytoskeleton. Swinholides were discovered from the marine sponge Theonella sp. and were long-suspected to be produced by symbiotic bacteria. Misakinolide, a structural variant of swinholide, was recently demonstrated to be the product of the symbiotic heterotrophic proteobacterium. Here we report the production of swinholide A by an axenic strain of the terrestrial cyanobacterium Nostoc sp...
November 17, 2017: Applied and Environmental Microbiology
Koichi Toyoda, Inui Masayuki
Mycolates are α-branched, β-hydroxylated, long-chain fatty acid specifically synthesized in bacteria in the suborder Corynebacterineae of the phylum Actinobacteria. They form an outer membrane, which functions as a permeability barrier and confers pathogenic mycobacteria to resistance to antibiotics. Although the mycolate biosynthetic pathway has been intensively studied, knowledge of transcriptional regulation of genes involved in this pathway is limited. Here we report that the extracytoplasmic function sigma factor σ(D) is a key regulator of the mycolate synthetic genes in Corynebacterium glutamicum in the suborder...
November 17, 2017: Molecular Microbiology
Hannu Hotti, Heiko Rischer
Coniine, a polyketide-derived alkaloid, is poisonous to humans and animals. It is a nicotinic acetylcholine receptor antagonist, which leads to inhibition of the nervous system, eventually causing death by suffocation in mammals. Coniine's most famous victim is Socrates who was sentenced to death by poison chalice containing poison hemlock in 399 BC. In chemistry, coniine holds two historical records: It is the first alkaloid the chemical structure of which was established (in 1881), and that was chemically synthesized (in 1886)...
November 14, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Li Li, Misbah Aslam, Fazle Rabbi, Mark C Vanderwel, Neil W Ashton, Dae-Yeon Suh
PpORS knockout mutants produced abnormal leaves with increased dye permeability and were more susceptible to dehydration, consistent with PpORS products being constituents of a cuticular structure in the moss. Type III polyketide synthases (PKSs) have co-evolved with terrestrial plants such that each taxon can generate a characteristic collection of polyketides, fine-tuned to its needs. 2'-Oxoalkylresorcinol synthase from Physcomitrella patens (PpORS) is basal to all plant type III PKSs in phylogenetic trees and may closely resemble their most recent common ancestor...
November 8, 2017: Planta
Reiko Ueoka, Miriam Bortfeld-Miller, Brandon Isamu Morinaka, Julia Anne Vorholt, Jörn Piel
Trans-AT polyketide synthases (PKSs) are biosynthetically versatile enzymes that generate bioactive polyketides of high structural diversity. In this study, we detected in the genome of several bacteria a cryptic, unusual trans-AT PKS gene cluster that eluded automated PKS prediction. Genomic mining of one of these strains, the model methylotroph Methylobacterium extorquens AM1, revealed epoxide-cyclopropanol-containing polyketides named toblerols. The stereochemistry was determined by NMR, chemical derivatization, and the comparison of CD data with those of a synthesized model compound...
November 7, 2017: Angewandte Chemie
Kajal Chakraborty, Bini Thilakan, Vinaya Kizhakkepatt Kizhakkekalam
AIMS: Microbiological, biotechnological and chemical characterization of a previously undescribed aryl-crowned polyketide from Bacillus subtilis MTCC 10403 isolated from brown seaweed Anthophycus longifolius with activity against opportunistic Gram-negative food-borne pathogenic bacterial strains. METHODS AND RESULTS: A culture-dependent method was used to isolate heterotrophic B. subtilis associated with A. longifolius, and assessed for its antimicrobial properties...
November 6, 2017: Journal of Applied Microbiology
Xueqiang Su, Xu Sun, Xi Cheng, Yanan Wang, Muhammad Abdullah, Manli Li, Dahui Li, Junshan Gao, Yongping Cai, Yi Lin
Plant type III polyketide synthase (PKS) can catalyse the formation of a series of secondary metabolites with different structures and different biological functions; the enzyme plays an important role in plant growth, development and resistance to stress. At present, the PKS gene has been identified and studied in a variety of plants. Here, we identified 11 PKS genes from upland cotton (Gossypium hirsutum) and compared them with 41 PKS genes in Populus tremula, Vitis vinifera, Malus domestica and Arabidopsis thaliana...
2017: PeerJ
Christian Derntl, Fernando Guzmán-Chávez, Thiago M Mello-de-Sousa, Hans-Jürgen Busse, Arnold J M Driessen, Robert L Mach, Astrid R Mach-Aigner
Sorbicillinoids are a diverse group of yellow secondary metabolites that are produced by a range of not closely related ascomycetes, including Penicillium chrysogenum, Acremonium chrysogenum, and Trichoderma reesei. They share a similarity to the name-giving compound sorbicillin, a hexaketide. Previously, a conserved gene cluster containing two polyketide synthases has been identified as the source of sorbicillin, and a model for the biosynthesis of sorbicillin in P. chrysogenum has been proposed. In this study, we deleted the major genes of interest of the cluster in T...
2017: Frontiers in Microbiology
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