title: Physical and functional characteristics of R-factor deoxyribonucleic acid segregated into Escherichia coli minicells.
abstract: Both fi(+) and fi(-) type R factors function as intact replicative units when segregated into Escherichia coli minicells. Hybridization studies demonstrate that at least 95% of the deoxyribonucleic acid (DNA) in R(+) minicells is episomal in origin. About half of the DNA can be extracted in a closed circular form and about 75% of the DNA is membrane associated. DNA, ribonucleic acid, and protein synthesis proceeds in R(+) minicells in contrast to R(-) minicell controls. The system offers a unique opportunity to study a relatively small replicative unit in a native cell environment and a simple means of isolating large quantities of episomal DNA.
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis; D001665:Binding Sites; D002247:Carbon Isotopes; D002462:Cell Membrane / Q000378:metabolism; D002499:Centrifugation, Density Gradient; D002586:Cesium; D002712:Chlorides; D004269:DNA, Bacterial / Q000032:analysis / Q000096:biosynthesis; D004352:Drug Resistance, Microbial; D004589:Electrophoresis, Disc; D004926:Escherichia coli / Q000032:analysis / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D005827:Genetics, Microbial; D007930:Leucine / Q000378:metabolism; D009154:Mutation; D009693:Nucleic Acid Hybridization; D012316:RNA Nucleotidyltransferases / Q000378:metabolism; D012329:RNA, Bacterial / Q000096:biosynthesis; D012293:Rifampin / Q000494:pharmacology; D013395:Sucrose; D013936:Thymidine / Q000378:metabolism; D014316:Tritium; D014498:Uracil / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D002247:Carbon Isotopes; D002712:Chlorides; D004269:DNA, Bacterial; D012329:RNA, Bacterial; D014316:Tritium; D002586:Cesium; D014498:Uracil; D013395:Sucrose; D012316:RNA Nucleotidyltransferases; D007930:Leucine; D013936:Thymidine; D012293:Rifampin