title: Location of the origin of replication for the 7.5-kb Chlamydia trachomatis plasmid.
abstract: The hypothetical origin of replication for the 7.5-kb plasmid common to Chlamydia trachomatis is believed to be in a region of the plasmid that contains four 22-bp tandem repeats preceded by an A-T-rich region. To test this hypothesis, replication of plasmid DNA in metabolically active reticulate bodies of the Lymphogranuloma venereum biovar of C. trachomatis was examined by electron microscopy. The results presented show that the origin of replication appears to be near the tandem repeats of pCHL2. In addition, replication of the 7.5-kb plasmid is unidirectional, and the copy number during replication is 7-10. The evidence presented suggests that C. trachomatis has a homologue to the Escherichia coli dnaA gene and that this homologue might be involved in replication of the C. trachomatis 7.5-kb plasmid.
authors.affiliation: Department of Microbiology and Immunology, University of North Carolina School of Medicine, Chapel Hill 27514.
authors.forename: J E
authors.initials: JE
authors.lastname: Tam
authors.forename: C H
authors.initials: CH
authors.lastname: Davis
authors.forename: R J
authors.initials: RJ
authors.lastname: Thresher
authors.forename: P B
authors.initials: PB
authors.lastname: Wyrick
mesh_terms: D001483:Base Sequence; D002692:Chlamydia trachomatis / Q000235:genetics*; D004261:DNA Replication; D004269:DNA, Bacterial / Q000235:genetics / Q000648:ultrastructure; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D010957:Plasmids; D012045:Regulatory Sequences, Nucleic Acid; D012091:Repetitive Sequences, Nucleic Acid
chemical_list: D004269:DNA, Bacterial