title: Synthesis of ribonucleic acid and protein in plasmid-containing minicells of Escherichia coli K-12.
abstract: Unlike the deoxyribonucleic acid (DNA)-deficient minicells produced by F(-) parents, minicells produced by plasmid-containing strains contain significant amounts of plasmid DNA. We examined the ability of plasmid-containing minicells to synthesize ribonucleic acid (RNA) and protein. In vivo, minicells produced by F(-) parents are unable to incorporate radioactive precursors into acid-insoluble RNA or protein, whereas minicells produced by F', R(+), or Col(+) parents are capable of such synthesis. Using a variety of approaches, including polyacrylamide gel analysis of the RNA species produced and electron microscope autoradiography, we demonstrated that the synthesis observed in minicell preparations is a property of the plasmid-containing minicells and not a result of the few cells (approximately 1 per 10(6) minicells) contaminating the preparations. That the observed synthesis is of biological importance is suggested by the ability of plasmid-containing minicells to yield viable phage upon infection with T4.
mesh_terms: D000667:Ampicillin / Q000494:pharmacology; D001345:Autoradiography; D001426:Bacterial Proteins / Q000096:biosynthesis*; D002247:Carbon Isotopes; D002499:Centrifugation, Density Gradient; D002701:Chloramphenicol / Q000494:pharmacology; D003090:Coliphages / Q000254:growth & development; D003227:Conjugation, Genetic; D004269:DNA, Bacterial; D004589:Electrophoresis, Disc; D004926:Escherichia coli / Q000166:cytology / Q000187:drug effects / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism*; D005827:Genetics, Microbial; D007930:Leucine / Q000378:metabolism; D008242:Lysogeny; D008854:Microscopy, Electron; D010403:Penicillin Resistance; D011492:Protein Hydrolysates / Q000378:metabolism; D012329:RNA, Bacterial / Q000096:biosynthesis* / Q000302:isolation & purification; D012343:RNA, Transfer; D011995:Recombination, Genetic; D012293:Rifampin / Q000494:pharmacology; D013053:Spectrophotometry; D013395:Sucrose; D014316:Tritium; D014364:Tryptophan / Q000378:metabolism; D014498:Uracil / Q000378:metabolism; D014529:Uridine / Q000378:metabolism; D014779:Virus Replication
chemical_list: D001426:Bacterial Proteins; D002247:Carbon Isotopes; D004269:DNA, Bacterial; D011492:Protein Hydrolysates; D012329:RNA, Bacterial; D014316:Tritium; D014498:Uracil; D013395:Sucrose; D002701:Chloramphenicol; D000667:Ampicillin; D014364:Tryptophan; D012343:RNA, Transfer; D007930:Leucine; D012293:Rifampin; D014529:Uridine