title: Unidirectional replication in Escherichia coli of three small plasmids derived from R factor R12.
mesh_terms: D004261:DNA Replication; D004269:DNA, Bacterial / Q000235:genetics; D004270:DNA, Circular / Q000235:genetics; D004720:Endonucleases / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics*; D008854:Microscopy, Electron; D009690:Nucleic Acid Conformation; D011815:R Factors
chemical_list: D004269:DNA, Bacterial; D004270:DNA, Circular; D004720:Endonucleases