Abstract
The low-copy-number 8.7-kb plasmid pGIF3 of Streptomyces incarnatus was studied after cloning in the Escherichia coli vector pBR322; a restriction map was constructed. Southern blot analysis showed that pGIF3 in S. incarnatus occurs predominantly as integrated in a larger replicon. The plasmid carries a gene for thiostrepton resistance having no homology with the known thiostrepton resistance gene from Streptomyces azureus.