Cloning of the replication region on the bacteriocinogenic plasmid pRJ9 of Staphylococcus aureus

A 5.8-kb ClaI fragment of pRJ9, a bacteriocinogenic plasmid of Staphylococcus aureus, was cloned in the unique ClaI site of pRJ5. The recombinant plasmid obtained, pRJ23, failed to confer bacteriocin production and immunity to bacteriocin on host cells. The cloned fragment was shown to contain the complete replicon of pRJ9. Attempts to clone the 4.4-kb ClaI fragment of pRJ9 were unsuccessful, apparently due to the inactivation of the basic replicon of the cloning vector. Therefore, plasmid pRJ5 cut at its ClaI site appears to be a suitable vector for cloning replication regions of plasmids that can replicate in S. aureus.