title: Integration of the Vwa plasmid into the chromosome of Yersinia pestis strains harboring F' plasmids of Escherichia coli.
abstract: Conditional virulent strains of Yersinia pestis were used as recipients of an F-lac plasmid from either Escherichia coli 23.10S or E. coli CSH23. The transconjugants of Y. pestis were calcium independent; however, calcium dependence was restored after the loss of the E. coli plasmid. The plasmid contents of several Y. pestis F-lac clones were compared with those of the parent strains and several lac segregants. Although the 6- and 61-megadalton plasmids were detected in all strains tested, the Vwa plasmid was absent in the F-containing strains. The plasmid was evident, however, in the lac segregants derived from the F-lac clones. Results of Southern transfers indicated that the Vwa plasmid had integrated into the chromosome of Y. pestis strains harboring F-lac.
mesh_terms: D002118:Calcium / Q000502:physiology; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics*; D005144:F Factor; D007763:Lac Operon; D010957:Plasmids; D015010:Yersinia pestis / Q000235:genetics*
chemical_list: D004269:DNA, Bacterial; D002118:Calcium