Bremer H, Churchward G
J Bacteriol. 1985 Nov;164(2):922-4. doi: 10.1128/jb.164.2.922-924.1985.
Escherichia coli HB282 carries a dnaA46(Ts) allele on the chromosome, a wild-type dnaA allele under the control of the lacUV5 promoter on the multicopy plasmid pBC32, and an overproducing lac repressor allele on an F' factor. When the plasmid dnaA gene is repressed, the strain is thermosensitive. After a temporary deficiency in active dnaA protein at nonpermissive temperature, the addition of isopropyl-beta-D-thiogalactopyranoside to the culture was found to produce a burst of initiations within 5 to 10 min at 30% of the origins in 90% of the cells. Initiations then continued at a rate slightly faster than the mass-doubling time such that after 2 h the origin-to-mass ratio of the control culture was restored.
大肠杆菌HB282在染色体上携带一个dnaA46（Ts）等位基因，在多拷贝质粒pBC32上的lacUV5启动子控制下有一个野生型dnaA等位基因，并且在F'因子上有一个过量表达的lac阻遏物等位基因。当质粒dnaA基因被抑制时，该菌株是温度敏感型的。在非允许温度下活性dnaA蛋白暂时缺乏后，发现向培养物中添加异丙基-β-D-硫代半乳糖苷会在90%的细胞中30%的起始位点处5至10分钟内产生一轮起始爆发。然后起始以略快于质量加倍时间的速率继续，使得2小时后对照培养物的起始位点与质量比得以恢复。
