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From a Natural Product to Its Biosynthetic Gene Cluster: A Demonstration Using Polyketomycin from Streptomyces diastatochromogenes Tü6028
Published on: January 13, 2017
Putative monofunctional type I polyketide synthase units: a dinoflagellate-specific feature?
Karsten Eichholz1, Bánk Beszteri, Uwe John
1Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany.
Plos One
|November 10, 2012
Summary
Marine dinoflagellates possess unique Type I polyketide synthase (PKS) genes, expressing them as single ketoacylsynthase (KS) domains. This atypical structure may be specific to dinoflagellates and linked to phycotoxin production.
Area of Science:
- Marine biology
- Molecular biology
- Biochemistry
Background:
- Marine dinoflagellates are microalgae, some causing harmful algal blooms and producing phycotoxins.
- Novel polyketide synthase (PKS) transcripts in Karenia brevis suggest atypical PKS structures.
Purpose of the Study:
- Investigate the expression of PKS I-like sequences in Alexandrium ostenfeldii and Heterocapsa triquetra.
- Determine if the atypical PKS structure observed in K. brevis is a broader dinoflagellate feature.
Main Methods:
- Transcriptome analysis to obtain full-length PKS transcripts.
- Western blot analysis using dinoflagellate-specific KS antibodies.
- Phylogenetic analysis of ketoacylsynthase (KS) domains.
Main Results:
- Five full-length PKS transcripts were identified, each encoding a single KS domain.
- Protein analysis confirmed the monofunctional expression of these KS domains.
- Dinoflagellate KS domains formed a distinct clade within the Type I PKS group.
- A novel, conserved N-terminal domain was discovered in dinoflagellate PKS transcripts.
Conclusions:
- The expression of PKS I as monofunctional units appears to be a specific characteristic of dinoflagellates.
- The novel N-terminal domain's role in this organization warrants further investigation.
- Understanding these PKS structures may shed light on phycotoxin biosynthesis.
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