Genome Sequencing of Streptomyces griseus SCSIO PteL053, the Producer of 2,2'-Bipyridine and Actinomycin Analogs, and Associated Biosynthetic Gene Cluster Analysis

Marine symbiotic actinomycetes play a key role in drug development and their ecological niches can influence a variety of natural product biosynthesis, providing potential defensive benefits. In this study, we report the whole-genome sequence analysis of marine gastropod mollusk Planaxis sp.-associated Streptomyces griseus SCSIO PteL053, which harbors 28 putative biosynthetic gene clusters (BGCs). Among them, two BGCs encoded by a hybrid non-ribosomal peptide (NRPS)/polyketide (PKS) synthetase and non-ribosomal peptide synthetase (NRPS) are responsible for the synthesis of the known therapeutic metabolites 2,2 '-bipyridine and actinomycin analogs, respectively. Detailed bioinformatics analysis revealed the putative BGCs and the functions of the involved genes in the biosynthesis of the known compounds SF2738D (1), SF2738F (2), actinomycin D (3), and Actinomycin X-o beta (4). In the present study, complete-genome sequencing allowed us to rediscover known, clinically useful secondary metabolites in the newly isolated Streptomyces griseus SCSIO PteL053.