Production of extrachromosomal r-determinant circles from integrated R100.1: involvement of the E. coli recombination system
| Autor: | Lynn L. Silver, L. Caro, Lane He, Michael Chandler |
|---|---|
| Rok vydání: | 1980 |
| Předmět: |
Genetics
DNA Replication DNA Bacterial Autonomously replicating sequence R Factors Extrachromosomal Inheritance Chromosome biochemical phenomena metabolism and nutrition Biology Plasmid Phenotype Genes Extrachromosomal DNA Hfr cell Operon Escherichia coli bacteria Repressor lexA DNA Circular Molecular Biology Gene Recombination |
| Zdroj: | Scopus-Elsevier |
| ISSN: | 0026-8925 |
| Popis: | The drug resistance plasmid R100.1 can integrate into the E. coli chromosome at several sites on the plasmid. Many of the resulting Hfr strains continuously produce extrachromosomal circular forms of the r-determinant. These r-det 'plasmids' seem incapable of stable autonomous replication. We show that their presence in the cell requires the continuous activity of functional recA and recC genes but does not require the lexA function. The production of r-det circular forms is correlated with an increased copy number of r-det sequences, relative to RTF sequences, This copy number increase is, however, also found in a recA- background where no circular forms of r-det are found. These results show that a specific replication of r-det sequences, not present in the wild-type R100.1 plasmid, occurs in these R-Hfr strains. They suggest that a rec promoted recombination, posterior to the specific replication event, is needed for the production of circular r-det forms. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full text from SpringerLink