Isolation and identification of venturicidins biosynthetic gene cluster from Streptomyces sp. NO1W98

Abstract:

[Objective] The aim of this study was to isolate venturicidins from Streptomyces sp. NO1W98 and identify their biosynthetic gene cluster.[Methods] The secondary metabolites were extracted from enlarged-scale fermentation broth of Streptomyces sp. NO1W98 with organic solvent, purified with normal and reverse phase silica gel chromatography and structure elucidated with spectroscopic approaches. The genomic DNA of Streptomyces sp. NO1W98 was extracted and sequenced by Illumina Hiseq technology. Gene cluster of venturicidins (vtd) was preliminarily located by bioinformatic analysis and verified by gene disruption and trans complementation. Different in fermentation extracts between Streptomyces sp. NO1W98 wild type and related mutants were analyzed with HPLC. [Results] Two macrolides, venturicidins A and B were isolated and their structures were identified from Streptomyces sp. NO1W98. Draft genome of Streptomyces sp. NO1W98 harbors 49 proposed secondary metabolite biosynthetic gene clusters, including the vtd located in Region 3.3 of scaffold 3 that is responsible for the biosynthesis of venturicidins. The vtd was preliminarily characterized by gene disruption of vtdA1, orf(-1), orf(+1) and then verified by gene complementation of vtdA1 to ΔvtdA1. The vtd was found to include 6 PKS skeleton genes, 5 transporter genes, 2 regulator genes and 9 post-PKS tailoring genes. [Conclusion] The isolation and identification of venturicidins and their biosynthetic gene cluster from Streptomyces sp. NO1W98 provide the basis for future genetic engineering and strain improvement.