Sequencing of Nocardiopsis linear plasmid pNPL1

Abstract:

[Objective] To detect and analyze linear plasmids from rare actinomycetes species. [Methods] Rare actinomycetes strains were isolated from plants, and linear plasmids were detected, sequenced and analyzed. [Results] An endophytic actinomycetes strain 25L-1-1c was isolated from Chinese herb Peucedanum decursivum. Its 16S rRNA gene sequence resembled Nocardiopsis. Strain 25L-1-1c harbored a linear plasmid pNPL1. The telomere of pNPL1 was cloned and sequenced, which was a novel sequence containing multiple palindromes. The complete nucleotide sequence of pNPL1 comprised 24 621 bp, encoding 22 genes, 2 of them resembling Streptomyces telomere replication genes, one major plasmid transfer gene, and others unknown functional genes. Plasmid containing the Nocardiopsis telomere replication genes could not propagate in S. lividans, indicating that development of Nocardiopsis genetic system is needed. [Conclusion] This is the first example of linear plasmid in Nocardiopsis.