Requirement of the Escherichia coli dnaA gene function for integrative suppression of dnaA mutations by plasmid R 100-1.
The phenotype of Escherichia coli dnaA missense and nonsense mutations was integratively suppressed by plasmid R100-1. The suppressed strains, however, could not survive when the dnaA function was totally inactivated. This was demonstrated by the inability of replacing the dnaA allele in the suppressed strain by a dnaA::Tn10 insertion using phage P1-mediated transduction. When the intact dnaA+ allele was additionally supplied by a specialized transducing phage, lambda imm21 dnaA+, which integrated at the att lambda site on the E. coli chromosome, then the dnaA::Tn10 insertion, together with a delta oriC deletion, were able to be introduced into the suppressed strain. Thus, the mechanisms of dnaA function for oriC and for the replication origin of R100-1 may not be quite the same.
Nagata
T
T
Institute for Virus Research, Kyoto University, Japan.
Murakami
Y
Y
Imai
M
M
D001426:Bacterial Proteins / Q000235:genetics*; D002872:Chromosome Deletion; D004261:DNA Replication; D004926:Escherichia coli / Q000235:genetics*; D005796:Genes; D005798:Genes, Bacterial; D009154:Mutation; D011815:R Factors; D013489:Suppression, Genetic; D014161:Transduction, Genetic
D001426:Bacterial Proteins