Recircularization and Autonomous Replication of a Sheared R-Factor DNA Segment in Escherichia coli Transformants*

AUTOR(ES)

Cohen, Stanley N.

RESUMO

Controlled shearing of R-factor DNA leads to formation of fragments carrying an antibiotic resistance gene present on, but not expressed by, the intact R-factor. Transformation of CaCl2-treated E. coli by such fragments yields an autonomously replicating tetracycline-resistance plasmid (Tc6-5) that contains only a small fraction of the genome of the parent R-factor, and lacks both its fertility functions and its other drug-resistance determinants. Although the Tc6-5 plasmid is not self-transmissible, it can interact and/or recombine with conjugally-proficient plasmids that promote its transfer to other bacteria.

Documentos Relacionados

• Nonchromosomal Antibiotic Resistance in Bacteria: Genetic Transformation of Escherichia coli by R-Factor DNA*
• Plasmid incompatibility and control of replication: copy mutants of the R-factor R1 in Escherichia coli K-12.
• Specific Labeling and Physical Characterization of R-Factor Deoxyribonucleic Acid in Escherichia coli
• Replication of R-factor R1 in Scherichia coli K-12 at different growth rates.
• Positive and Negative Control of R-Factor Replication in Proteus mirabilis