title: Comparison of 10 IncP plasmids: homology in the regions involved in plasmid replication.
abstract: We have examined the DNA homology in the replication regions of 10 IncP plasmids independently isolated from several different countries. Two regions of RK2, the best-studied plasmid of this group, are required for vegetative DNA replication: the origin of replication (oriV) and the trfA region, which codes for a gene product necessary for replication. Six of nine IncP plasmids studied were identical to RK2 in the oriV and trfA regions as shown by Southern hybridization. Three P plasmids, R751, R772, and R906, showed weaker homology with the RK2 trfA, region and hybridized to different-sized HaeII fragments than the other six plasmids. R751, R772, and R906 hybridized to the region of the RK2 replication origin which expresses P incompatibility but differed markedly from RK2 and the other six plasmids in the GC-rich region of the origin required for replication. These data indicate that the P-group plasmids can be divided into two subgroups: IncP alpha, which includes the RK2-like plasmids, and IncP beta which includes the R751-like plasmids.
authors.forename: G K
authors.initials: GK
authors.lastname: Chikami
authors.forename: D G
authors.initials: DG
authors.lastname: Guiney
authors.forename: T J
authors.initials: TJ
authors.lastname: Schmidhauser
authors.forename: D R
authors.initials: DR
authors.lastname: Helinski
mesh_terms: D004261:DNA Replication; D004262:DNA Restriction Enzymes; D004269:DNA, Bacterial / Q000235:genetics*; D005798:Genes, Bacterial; D010957:Plasmids; D013045:Species Specificity
chemical_list: D004269:DNA, Bacterial; D004262:DNA Restriction Enzymes