We have cloned the EcoRI fragments of pLC1, a circular DNA element found in an Escherichia coli dnaAts strain integratively suppressed by R100.1 (Chandler et al., 1977a), using the plasmid vector pCR1. All the resistance genes known to be present on the r-determinant of R100.1 were found to be prese
Involvement of IS1 in the dissociation of the r-determinant and RTF components of the plasmid R100.1
โ Scribed by Chandler, M. ;Allet, B. ;Gallay, E. ;Boy de La Tour, E. ;Caro, L.
- Publisher
- Springer
- Year
- 1977
- Tongue
- English
- Weight
- 721 KB
- Volume
- 153
- Category
- Article
- ISSN
- 0026-8925
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โฆ Synopsis
The formation of the r-determinant pLC1 and of the RTF pAR132 from the composite plasmid R100.1 was investigated. The general location of IS1 sequences on the three plasmids was established by hybridization of lambdar14 CII::IS1 DNA to EcoRI generated fragments of the various plasmids separated by agarose gel electrophoresis and transferred directly to nitrocellulose filters. The position of IS1 sequences on these fragments and the homologies between fragments were analyzed by electron microscopy of heteroduplex molecules. The results show that the excision of both pLC1 and pAR132 occurred by an exchange between the two IS1 sequences present on R100.1.
๐ SIMILAR VOLUMES
We have cloned the entire r-determinant of the antibiotic resistance plasmid R100.1 on the plasmic vectors pCR1 and pSC201. We find that the hybrid plasmids segregate from cultures in which replication of the vector is blocked. This suggests that the r-det is not capable of autonomous replication.
The rate of replication of the plasmids colE1, pSC101, R100.1 and pAR132 (an RTF-TC derivative of the drug resistance factor R100.1) has been investigated directly by DNA:DNA hybridization. These rates have been compared, in a dnaAts strain, to that of various markers of the host chromosome at permi
Tra+ and tra- derivatives of drug resistance plasmid, R100-1, were isolated by phage P1 from an Hfr donor with integrated R100-1 and then analyzed by complementation tests with tra- point mutants of Flac. Tra+ derivatives of R100-1 carrying tetracycline resistance alone and those carrying all six dr