Isolation of a temperature-sensitive dnaA mutant of Staphylococcus aureus.
Of 750 temperature-sensitive mutants of Gram-positive Staphylococcus aureus, one was complemented by the dnaA gene. This mutant had a single base transition in the dnaA gene causing the amino-acid substitution mutation, Ala40Thr. Phage transduction experiments showed that this temperature-sensitive phenotype was linked with a drug-resistant marker inserted near the dnaA gene, suggesting the dnaA mutation is responsible for the phenotype. Flow cytometric analysis revealed that the dnaA mutant was unable to initiate DNA replication at a restrictive temperature and exhibited asynchrony in the replication initiation at a permissive temperature. This is the first report of a temperature-sensitive dnaA mutant in S. aureus, and the results show that DnaA is required for the initiation of chromosomal replication and for the regulation of synchrony in the bacterial cells.
Murai
Nagamoto
N
Laboratory of Developmental Biochemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan.
Kurokawa
Kenji
K
Ichihashi
Norikazu
N
Matsuo
Miki
M
Sekimizu
Kazuhisa
K
D001426:Bacterial Proteins / Q000235:genetics*; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000235:genetics*; D005434:Flow Cytometry; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D009154:Mutation; D017422:Sequence Analysis, DNA; D013211:Staphylococcus aureus / Q000235:genetics / Q000254:growth & development* / Q000302:isolation & purification*; D013696:Temperature
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C066312:DnaA protein, Bacteria