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Novel alleles of the Escherichia coli dnaA gene
- Source :
- Journal of Molecular Biology. 271:693-703
- Publication Year :
- 1997
- Publisher :
- Elsevier BV, 1997.
-
Abstract
- The Escherichia coli dnaA gene is required for replication of the bacterial chromosome. To identify residues critical for its replication activity, a method to select novel mutations was developed that relied on lytic growth of λ from an inserted pSC101 replication origin. Replication from the λ origin was inhibited by lysogen-encoded c I repressor. Replication from the pSC101 origin that resulted in lytic growth was dependent on active DnaA protein encoded by a plasmid in a host strain lacking the chromosomal dnaA gene. With this approach, a large collection of missense, nonsense, and a few internal deletion mutations were obtained. Nucleotide sequence analysis of the missense mutations indicated that 28 of 50 were unique. Of these, one was identical to the dnaA205 allele whereas the remainder are novel. These missense mutations were clustered into three regions, suggesting three functional domains of DnaA protein required for its replication activity. Many of the missense mutations mapping to the C-terminal 61 residues were inactive for replication from the pSC101 origin. These are defective in DNA binding. Mutations that mapped elsewhere were temperature-sensitive.
- Subjects :
- DNA Replication
DNA, Bacterial
DNA Mutational Analysis
Replication Origin
medicine.disease_cause
Pre-replication complex
Origin of replication
DNA replication factor CDT1
Viral Proteins
Replication factor C
Bacterial Proteins
Structural Biology
medicine
Escherichia coli
Viral Regulatory and Accessory Proteins
Allele
Gene
Lysogeny
Molecular Biology
Alleles
Genetics
biology
DNA replication
Bacteriophage lambda
Molecular biology
DnaA
DNA-Binding Proteins
Repressor Proteins
Genes, Bacterial
Prokaryotic DNA replication
Mutation
biology.protein
bacteria
Origin recognition complex
Subjects
Details
- ISSN :
- 00222836
- Volume :
- 271
- Database :
- OpenAIRE
- Journal :
- Journal of Molecular Biology
- Accession number :
- edsair.doi.dedup.....741ee0fb485f1d39e9595fce05fc4179