Suppression of an Escherichia coli dnaA mutation by the integrated R factor R.100.1: Change of chromosome replication origin in synchronized cultures.
AUTOR(ES)
Bird, R E
RESUMO
We have followed, by deoxyribonucleic acid-deoxyribonucleic acid hybridization, the order of replication of three chromosomal markers during a synchronous round of replication in three strains of Escherichia coli carrying a dnaAts mutation: one strain in which the F-like R factor R.100.1 was established as a plasmid and two strains in which the dnaA mutation was suppressed by the integration of R.100.1 into the chromosome. In the R+ strain at 30C, replication of the plasmid took place simultaneously with the initiation of chromosome replication at the normal origin. In the integratively suppressed Hfr strains, at 42.5 C, chromosome replication was initiated preferentially from the integrated plasmid; little or no initiation occurred at the normal origin. Similar results were obtained for the one strain tested at 30 C. For both Hfr strains at 42.5 C, the data suggest that at least part of the population replicated bidirectionally. This conclusion had been confirmed using an autoradiographic procedure. Both types of experiment indicate a wide variation in the rate of travel of individual replication forks within the population.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=233146Documentos Relacionados
- Suppression of an Escherichia coli dnaA mutation by the integrated R factor R100.1: origin of chromosome replication during exponential growth.
- Suppression of an Escherichia coli dnaA mutation by the integrated R factor R100.1: generation of small plasmids after integration.
- Origin and direction of replication of the drug resistance plasmid R100.1 and of a resistance transfer factor derivative in synchronized cultures.
- Suppression of Escherichia coli dnaA46 mutations by integration of plasmid R100.1. derivatives: constraints imposed by the replication terminus.
- Identification and Mapping of the Replication Genes of an R Factor, R100-1, Integrated into the Chromosome of Escherichia coli K-12