Biochemical and genetic study of the regulatory mechanism of the chromosomal DNA replication in Escherichia coli

大肠杆菌染色体DNA复制调控机制的生化和遗传学研究

• 批准号: 06454600
• 负责人: SEKIMIZU Kazuhisa
• 金额: $ 4.29万
• 依托单位: KYUSHU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06454600/
• 关键词: DnaA protein; DNA replication; chromosomal DNA; Escherichia coli.; ATP-binding; phospholipid; DNA topoisomerase; cell cycle; oriC; DNAポリメラーゼ; 脂質; dnaA変異株; ATPピリドキサール; DnaA protein; DNA replication; chromosomal DNA; Escherichia coli.; ATP-binding; phospholipid; DNA topoisomerase; cell cycle; oriC; DNAポリメラーゼ; 脂質; dnaA変異株; ATPピリドキサール

DnaA protein is the initiator of chromosomal DNA replication in Escherichia coli. The head investigator and colleagues showed that DnaA protein is activated by acidic phospholipids including cardiolipin. In this study, we examined the influcnce of mixed liposomes composed of two different synthetic lipids on the ATP-binding of DnaA protein. The result showed that the cluster structure of acidic lipid is necessary for the interaction of acidic lipid in the mixed membrane with DnaA protein. This finding suggests a new insight for the regulation of the activity of DnaA protein, the initiator protein of DNA replication, in the cycle of cell division. Namely, acidic phospholipids may form either the cluster of dispersd structures in cell membrane, and that structural alternation of lipid structure may be coupled with cell cycle and it activates DnaA protein resulting the initiation of DNA replication.Further, we first reported the influence of DnaA protein on the supercoiled structure of double stranded DNA.We showed that DNA is more negatively supercoiled when the reaction of DNA topoisomerase was carried out in the presence of DnaA protein. This activity of DnaA protein was not dependent on sequence of DNA and was specifically inhibited by binding of DnaA protein to adenine nucleotide.

DNAA蛋白是大肠杆菌中染色体DNA复制的引发剂。首席研究员及其同事表明，DNAA蛋白被包括心磷脂在内的酸性磷脂激活。在这项研究中，我们检查了由DNAA蛋白的ATP结合上的两种不同合成脂质组成的混合脂质体的诱变。结果表明，酸性脂质的簇结构对于混合膜中酸性脂质与DNAA蛋白的相互作用是必需的。这一发现表明，在细胞分裂循环中，DNAA蛋白的活性（DNAA蛋白的活性（DNAA蛋白）的活性是一种新的见解。就是说，酸性磷脂可能形成细胞膜中分散结构的簇，并且脂质结构的结构交替可以与细胞周期相结合，并且激活DNAA蛋白，从而引发DNA的蛋白质，从而引发DNA复制。FURTHER。我们首先报道了DNAA蛋白对dnaa蛋白的影响，而DNAA蛋白对DEAD NA. DENNA的影响更高。在DNAA蛋白存在下进行拓扑异构酶。 DNAA蛋白的这种活性不依赖于DNA的序列，并通过DNAA蛋白与腺嘌呤核苷酸的结合特异性抑制。