Characterization and Localization of a Hybrid Non-ribosomal Peptide Synthetase and Polyketide Synthase Gene from the Toxic Dinoflagellate Karenia brevis

2009 ◽  
Vol 12 (1) ◽  
pp. 32-41 ◽  
Author(s):  
Susanna López-Legentil ◽  
Bongkeun Song ◽  
Michael DeTure ◽  
Daniel G. Baden
Keyword(s):  
Polyketide Synthase ◽  
Karenia Brevis ◽  
Toxic Dinoflagellate ◽  
Peptide Synthetase ◽  
Polyketide Synthase Gene

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

scholarly journals Inhibition of Grape Crown Gall by Agrobacterium vitis F2/5 Requires Two Nonribosomal Peptide Synthetases and One Polyketide Synthase

2016 ◽  
Vol 29 (2) ◽  
pp. 109-118 ◽  
Author(s):  
Desen Zheng ◽  
Thomas J. Burr
Keyword(s):  
Crown Gall ◽  
Polyketide Synthase ◽  
Wild Type ◽  
Tissue Necrosis ◽  
Agrobacterium Vitis ◽  
Nonribosomal Peptide ◽  
Crown Gall Disease ◽  
Peptide Synthetases ◽  
Peptide Synthetase ◽  
Polyketide Synthase Gene

Agrobacterium vitis nontumorigenic strain F2/5 is able to inhibit crown gall disease on grapevines. The mechanism of grape tumor inhibition (GTI) by F2/5 has not been fully determined. In this study, we demonstrate that two nonribosomal peptide synthetase (NRPS) genes (F-avi3342 and F-avi5730) and one polyketide synthase gene (F-avi4330) are required for GTI. Knockout of any one of them resulted in F/25 losing GTI capacity. We previously reported that F-avi3342 and F-avi4330 but not F-avi5730 are required for induction of grape tissue necrosis and tobacco hypersensitive response. F-avi5730 is predicted to encode a single modular NRPS. It is located in a cluster that is homologous to the siderophore vicibactin biosynthesis locus in Rhizobium species. Individual disruption of F-avi5730 and two immediate downstream genes, F-avi5731 and F-avi5732, all resulted in reduced siderophore production; however, only F-avi5730 was found to be required for GTI. Complemented F-avi5730 mutant (ΔF-avi5730+) restored a wild-type level of GTI activity. It was determined that, over time, populations of ΔF-avi4330, ΔF-avi3342, and ΔF-avi5730 at inoculated wound sites on grapevine did not differ from those of ΔF-avi5730+ indicating that loss of GTI was not due to reduced colonization of wound sites by mutants.

scholarly journals Localization of polyketide synthase encoding genes to the toxic dinoflagellate Karenia brevis

2005 ◽  
Vol 66 (15) ◽  
pp. 1767-1780 ◽  
Author(s):  
Richard V. Snyder ◽  
Maria A. Guerrero ◽  
Christopher D. Sinigalliano ◽  
Jamie Winshell ◽  
Roberto Perez ◽  
...  
Keyword(s):  
Polyketide Synthase ◽  
Karenia Brevis ◽  
Toxic Dinoflagellate ◽  
Encoding Genes

scholarly journals Metagenomic Analysis Reveals Diverse Polyketide Synthase Gene Clusters in Microorganisms Associated with the Marine Sponge Discodermia dissoluta

2005 ◽  
Vol 71 (8) ◽  
pp. 4840-4849 ◽  
Author(s):  
Andreas Schirmer ◽  
Rishali Gadkari ◽  
Christopher D. Reeves ◽  
Fadia Ibrahim ◽  
Edward F. DeLong ◽  
...  
Keyword(s):  
Marine Sponge ◽  
Polyketide Synthase ◽  
Pcr Amplification ◽  
Gene Clusters ◽  
Type I ◽  
Metagenomic Libraries ◽  
Dna Libraries ◽  
Peptide Synthetase ◽  
Sponge Associated Bacteria ◽  
Polyketide Synthase Gene

ABSTRACT Sponge-associated bacteria are thought to produce many novel bioactive compounds, including polyketides. PCR amplification of ketosynthase domains of type I modular polyketide synthases (PKS) from the microbial community of the marine sponge Discodermia dissoluta revealed great diversity and a novel group of sponge-specific PKS ketosynthase domains. Metagenomic libraries totaling more than four gigabases of bacterial genomes associated with this sponge were screened for type I modular PKS gene clusters. More than 90% of the clones in total sponge DNA libraries represented bacterial DNA inserts, and 0.7% harbored PKS genes. The majority of the PKS hybridizing clones carried small PKS clusters of one to three modules, although some clones encoded large multimodular PKSs (more than five modules). The most abundant large modular PKS appeared to be encoded by a bacterial symbiont that made up <1% of the sponge community. Sequencing of this PKS revealed 14 modules that, if expressed and active, is predicted to produce a multimethyl-branched fatty acid reminiscent of mycobacterial lipid components. Metagenomic libraries made from fractions enriched for unicellular or filamentous bacteria differed significantly, with the latter containing numerous nonribosomal peptide synthetase (NRPS) and mixed NRPS-PKS gene clusters. The filamentous bacterial community of D. dissoluta consists mainly of Entotheonella spp., an unculturable sponge-specific taxon previously implicated in the biosynthesis of bioactive peptides.

scholarly journals Tetrodotoxins (TTXs) and Vibrio alginolyticus in Mussels from Central Adriatic Sea (Italy): Are They Closely Related?

Marine Drugs ◽  
2021 ◽  
Vol 19 (6) ◽  
pp. 304
Author(s):  
Simone Bacchiocchi ◽  
Debora Campacci ◽  
Melania Siracusa ◽  
Alessandra Dubbini ◽  
Francesca Leoni ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Mytilus Galloprovincialis ◽  
Polyketide Synthase ◽  
Adriatic Sea ◽  
Tandem Mass ◽  
Hydrophilic Interaction ◽  
Marche Region ◽  
Peptide Synthetase ◽  
Scientific Opinion ◽  
Vibrio Spp

Tetrodotoxins (TTXs), potent neurotoxins, have become an increasing concern in Europe in recent decades, especially because of their presence in mollusks. The European Food Safety Authority published a Scientific Opinion setting a recommended threshold for TTX in mollusks of 44 µg equivalent kg−1 and calling all member states to contribute to an effort to gather data in order to produce a more exhaustive risk assessment. The objective of this work was to assess TTX levels in wild and farmed mussels (Mytilus galloprovincialis) harvested in 2018–2019 along the coastal area of the Marche region in the Central Adriatic Sea (Italy). The presence of Vibrio spp. carrying the non-ribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) genes, which are suspected to be involved in TTX biosynthesis, was also investigated. Out of 158 mussel samples analyzed by hydrophilic interaction liquid chromatography coupled with tandem mass spectrometry (HILIC-MS/MS), 11 (7%) contained the toxins at detectable levels (8–26 µg kg−1) and 3 (2%) contained levels above the EFSA safety threshold (61–76 µg kg−1). Contaminated mussels were all harvested from natural beds in spring or summer. Of the 2019 samples, 70% of them contained V. alginolyticus strains with the NRPS and/or PKS genes. None of the strains containing NRPS and/or PKS genes showed detectable levels of TTXs. TTXs in mussels are not yet a threat in the Marche region nor in Europe, but further investigations are surely needed.

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