Replication of the ampicillin resistance plasmid RSF1030 in extracts of Escherichia coli: Separation of the replication cycle into early and late stages
✍ Scribed by Staudenbauer, Walter L.
- Publisher
- Springer
- Year
- 1977
- Tongue
- English
- Weight
- 722 KB
- Volume
- 156
- Category
- Article
- ISSN
- 0026-8925
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✦ Synopsis
The replication cycle of the small resistance plasmid RSF1030 can be divided into two stages with different enzyme requirements: (1) Synthesis of early replicative intermediates containing 7 S DNA catalyzed by DNA polymerase I in the absence of functional dnaZ protein, and (2) replication of early intermediates requiring DNA polymerase III holenzyme (including the dnaZ protein). Early intermediate DNA synthesized in a dnaZ extract can be converted to fully replicated plasmid molecules upon addition to a replication enzyme fraction prepared by ammonium sulfate fractionation of polA I extracts. The first-stage reaction is sensitive to rifampicin, novobiocin, and oxolinic acid, but insensitive to arabinosylcytosine triphosphate (aCTP). Addition of aCTP interferes with the second-stage reaction resulting in the accumulation of late replicative intermediates.