Genome-wide survey of polyketide synthase and nonribosomal peptide synthetase gene clusters in Streptomyces turgidiscabies NBRC 16081

Abstract

Although members of the genus Streptomyces are useful producers of secondary metabolites, Streptomyces turgidiscabies, a cause of potato scab, has not been investigated for this purpose. To examine the potential of S. turgidiscabies as a secondary metabolite producer, its polyketide synthase (PKS) and nonribosomal peptide synthetase (NRPS) gene clusters, conferring major biosynthetic pathways in actinomycetes, were surveyed using whole genome analysis of S. turgidiscabies NBRC 16081. This strain possessed seventeen PKS and NRPS gene clusters composed of two type-I PKS, two type-II PKS, seven NRPS, and six PKS/NRPS hybrid clusters. Abundance of these gene clusters was not only comparable to those of industrially useful strains such as S. avermitilis MA-4680 and S. griseus subsp. griseus NBRC 13350, but also superior to those of genetically well-studied S. coelicolor A3(2) and potato scab-causing S. scabiei 87.22. Remarkably, its PKS/NRPS gene clusters were more diverse in their module organization than those of other Streptomyces strains, although it possessed the lowest number of type-I PKS gene clusters. Our results suggest that S. turgidiscabies, unlike S. scabiei, harbors considerable genetic potential for producing diverse polyketide and peptide compounds.