| Literature DB >> 6946436 |
S A Khan, S M Carleton, R P Novick.
Abstract
PT181 is a naturally occurring 4.5-kilobase Staphylococcus aureus plasmid encoding resistance to tetracycline. The plasmid has a copy number of about 20 per cell; a mutant, cop-608, that has a copy number of 800-1000 has been isolated. A cell-free extract has been developed that carries out complete replication of this plasmid. Extracts made from a strain containing the mutant have much greater replication activity than do extracts of strains containing pT181. In an extract from which endogenous DNA has been removed, DNA synthesis is dependent upon the addition of exogenous plasmid DNA. The replication system is specific for pT181 and related plasmids but it is inactive with other S. aureus plasmids. Furthermore, pT181 DNA does not replicate in extracts made from plasmid-negative strains or strains containing other plasmids. The results suggest that a specific plasmid-encoded substance is required for the replication of pT181 DNA.Entities:
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Year: 1981 PMID： 6946436 PMCID： PMC320289 DOI： 10.1073/pnas.78.8.4902
Source DB: PubMed Journal: Proc Natl Acad Sci U S A ISSN： 0027-8424 Impact factor: 11.205