title: Plasmid DNA replication.
abstract: Recent studies have provided some insight to the overall characteristics of plasmid replication in bacteria. The ColE 1 and R6K plasmids replicate via a covalently-closed circular intermediate. Replication is initiated at a fixed origin and is unidirectional in the case of ColE 1 and bidirectional for R6K. In the case of the plasmid R6K. the bidirectional replication is asymmetric and sequential, proceeding from a fixed origin to a fixed terminus located approximately 20% of the R6K genome from the origin. RNA serves as a primer for plasmid DNA replication. The base composition and sequence of the 5'-terminus of the RNA segments in ColE 1 DNA have been determined. Finally, the properties of plasmid relaxation complexes and the possible role of these complexes in plasmid DNA replication are discussed.
mesh_terms: D002701:Chloramphenicol / Q000494:pharmacology; D004261:DNA Replication / Q000187:drug effects; D004269:DNA, Bacterial / Q000032:analysis / Q000096:biosynthesis*; D004270:DNA, Circular / Q000032:analysis / Q000096:biosynthesis*; D004926:Escherichia coli; D005111:Extrachromosomal Inheritance; D005796:Genes; D008954:Models, Biological; D008970:Molecular Weight; D009154:Mutation; D009690:Nucleic Acid Conformation; D010957:Plasmids; D012329:RNA, Bacterial / Q000032:analysis
chemical_list: D004269:DNA, Bacterial; D004270:DNA, Circular; D012329:RNA, Bacterial; D002701:Chloramphenicol