title: Plasmid-protein relaxation complexes in Staphylococcus aureus.
abstract: Protein-deoxyribonucleic acid relaxation complexes have been demonstrated for six Staphylococcus aureus plasmids out of sixteen examined. Four of these encode stretomycin resistence, have molecular weights of about 2.7 x 10(6), and are isolated as supercoiled molecules that are virtally 100% relaxable by treatment with sodium dodecyl sulfate. It is probable that these four isolates represent a single widely disseminated plasmid species. The other two plasmids showing relaxation complexes have molecular weights of about 3 x 10(6) and encode chloramphenicol resistance. The complexes in these cases are unstable, and it has not been possible to induce more than 50% relaxation by any of the standard treatments. Ten other plasmids do not show detectable complexes. These include three penicillinase plasmids, four tetracycline-resistance plasmids, one plasmid carrying kanamycin-neomycin resistance, and finally, two chloramphenicol-resistance plasmids.
mesh_terms: D001426:Bacterial Proteins / Q000302:isolation & purification*; D002701:Chloramphenicol / Q000494:pharmacology; D004269:DNA, Bacterial / Q000302:isolation & purification*; D004352:Drug Resistance, Microbial; D005111:Extrachromosomal Inheritance / Q000187:drug effects; D005947:Glucose / Q000494:pharmacology; D008970:Molecular Weight; D010957:Plasmids / Q000187:drug effects; D012965:Sodium Chloride / Q000494:pharmacology; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology; D013211:Staphylococcus aureus / Q000187:drug effects; D013307:Streptomycin / Q000494:pharmacology
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D012967:Sodium Dodecyl Sulfate; D012965:Sodium Chloride; D002701:Chloramphenicol; D005947:Glucose; D013307:Streptomycin