STREPTOMYCETE PLASMIDS CONTAINING BIOSYNTHESIS GENE CLUSTERS OF ANTITUMOR ANTIBIOTIC LIDAMICIN

Anticancer antibiotic lidamycin is produced by Streptomyces globisporus C-1027 strain. The lidamycin biosynthesis cluster (LDM-cluster) is localized on its plasmid SGLP1. Aim. To identify and characterize plasmid-localized gene clusters potentially involved in lidamycin biosynthesis in streptomycetes. Methods. Nucleotide sequences of streptomycetes from the Internet database Nucleotide Collection on the National Center for Biotechnology Information were objects of this study. Search for probable LDM clusters was performed using the Basic Local Alignment Search Tool. The LDM-cluster sequence of S. globisporus C-1027 was used as a query in BLASTN analysis. Results. The database contains information on the primary structures of thousands of chromosomes and dozens of plasmids of streptomycetes, which are fully defined (Compete genome). BLASTN-analysis of primary structures of DNAs revealed the presence of probable LDM clusters in 6 streptomycete plasmids. Nucleotide sequences of 7 plasmids were only partially identical – they all contained sequences that were similar to the fragment 7,747 bp – 112,237 bp of SGLP1. Conclusions. The findings have demonstrated that LDM clusters are predominantly localized on plasmids in Streptomyces species. Although the identified plasmids share substantial sequence similarity - spanning approximately 104.5 kb - with the reference SGLP1 plasmid, they are not genetically identical.