Complete genome sequence and comparative analysis of Streptomyces seoulensis, a pioneer strain of nickel superoxide dismutase

Background: Streptomyces seoulensis has contributed to the discovery and initiation of extensive research into nickel superoxide dismutase (NiSOD), a unique type of superoxide dismutase found in actinomycetes. Still so far, there is no information about whole genome sequence of this strain. Objective: To investigate complete genome sequence and perform bioinformatic analyses for genomic functions related with nickel-associated genes. Methods: DNA was extracted using the Wizard Genomic DNA Purification Kit then sequenced using a Pacific Biosciences SMRT cell 8Pac V3 DNA Polymerase Binding Kit P6 with the PacBiov2 RSII platform. We assembled the PacBio long-reads with the HGAP3 pipeline. Results: We obtained complete genome sequence of S. seoulensis, which comprises a 6,339,363 bp linear chromosome. While analyzing the genome to annotate the genomic function, we discovered the nickel-associated genes. We observed that the sodN gene encoding for NiSOD is located adjacent to the sodX gene, which encodes for the nickel-type superoxide dismutase maturation protease. In addition, several nickel-associated genes and gene clusters-nickel-responsive regulator, nickel uptake transporter, nickel–iron [NiFe]-hydrogenase and other putative genes were also detected. Strain specific genes were discovered through a comparative analysis of S. coelicolor and S. griseus. Further bioinformatic analyses revealed that this strain encodes at least 22 putative biosynthetic gene clusters, thereby implying that S. seoulensis has the potential to produce novel bioactive compounds. Conclusion: We annotated the genome and determined nickel-associated genes and gene clusters and discovered biosynthetic gene clusters for secondary metabolites implying that S. seoulensis produces novel types of bioactive compounds.