title: Isolation of minicircular deoxyribonucleic acids from wild strains of Escherichia coli and their relationship to other bacterial plasmids.
abstract: Supercoiled minicircular deoxyribonucleic acid (DNA) molecules with molecular weights of 1.8 x 10(6) and 2.3 x 10(6) have been isolated from two wild strains of Escherichia coli. DNA-DNA hybridization experiments indicate that these DNA molecules share extended homologies with the minicircular DNA of E. coli 15. The DNA of the colicinogenic factor E1 (ColE1) also hybridizes to a large extent with minicircular DNA of E. coli 15. In contrast, no hybridization could be detected with various large extrachromosomal DNA elements such as the colicinogenic factor V (ColV), the beta-hemolytic factor (Hly), or the P1-like DNA of E. coli 15. Two different insertion DNA species of E. coli integrated into lambdadg-DNA (lambdadg UP(in) 128, lambdadg UP(in) 308) do not show any annealing with minicircular DNA of E. coli 15.
mesh_terms: D002499:Centrifugation, Density Gradient; D003470:Culture Media; D004269:DNA, Bacterial / Q000302:isolation & purification*; D004926:Escherichia coli / Q000032:analysis* / Q000378:metabolism; D005111:Extrachromosomal Inheritance; D005827:Genetics, Microbial; D006824:Hybridization, Genetic; D002479:Inclusion Bodies; D008854:Microscopy, Electron; D008970:Molecular Weight; D010759:Phosphorus Isotopes; D013395:Sucrose; D013936:Thymidine / Q000378:metabolism; D014316:Tritium
chemical_list: D003470:Culture Media; D004269:DNA, Bacterial; D010759:Phosphorus Isotopes; D014316:Tritium; D013395:Sucrose; D013936:Thymidine