title: Novel F prime factors able to replicate in Escherichia coli Hfr strains.
abstract: A novel type of F' plasmid that can replicate extrachromosomally in cells of Hfr strains has been isolated. Genetic analysis of these plasmids indicates that all carry the dnaA-bglA region of the E. coli chromosome as well as ilv+ used as a selective marker. It is suggested that a specific site, designated poh+ (permissive on Hfr), is located in this region, and is essential for these plasmids to replicate in Hfr cells. The most interesting explanation, among others, would be that the poh+ site represents the replication origin of the bacterial chromosome.
mesh_terms: D002874:Chromosome Mapping; D003227:Conjugation, Genetic; D004261:DNA Replication; D004270:DNA, Circular / Q000096:biosynthesis; D004926:Escherichia coli / Q000378:metabolism*; D005111:Extrachromosomal Inheritance; D005144:F Factor; D005838:Genotype; D010957:Plasmids
chemical_list: D004270:DNA, Circular