THE ESCHERICHIA-COLI CELL-CYCLE AND THE PLASMID R1 REPLICATION CYCLE IN THE ABSENCE OF THE DNAA PROTEIN
THE ESCHERICHIA-COLI CELL-CYCLE AND THE PLASMID R1 REPLICATION CYCLE IN THE ABSENCE OF THE DNAA PROTEIN
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DOI：
10.1016/0092-8674(91)90269-5
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发表时间：
1991-03-22
期刊：
影响因子：
64.5
通讯作者：
NORDSTROM, K
中科院分区：
文献类型：
--
作者：
BERNANDER, R;DASGUPTA, S;NORDSTROM, K
在大肠杆菌EC：：71CW中，染色体复制受控于R1微型质粒pOU71。EC：：71CW的dna A850：：Tn10衍生物是活的，这证实了R1可以在没有Dna A蛋白的情况下复制。然而，由于染色体复制不足，复制开始的频率降低，细胞分裂受到严重干扰。复制和细胞分裂都可以通过增加REPA的产生而恢复正常，REPA是从整合的R1起源开始复制的限速蛋白。因此，REPA蛋白似乎在复制和组装复制体的复制和组装过程中弥补了DNAA的缺失。鉴于这些结果，讨论了Dna A蛋白在启动DNA复制中的作用，以及作为大肠杆菌染色体复制和细胞分裂周期的整体调节因子。
In E. coli strain EC::71CW chromosome replication is under the control of the R1 miniplasmid pOU71. A dnaA850::Tn10 derivative of EC::71CW was viable, which confirmed that R1 can replicate in the absence of the DnaA protein. The frequency of initiation of replication was, however, lowered and cell division was severely disturbed due to underreplication of the chromosome. Both replication and cell division could be restored to normal by increasing the production of RepA, the rate-limiting protein for initiation of replication from the integrated R1 origin. Therefore, the RepA protein seems to compensate for the absence of DnaA in the initiation of replication and assembly of replisomes. The role of the DnaA protein in the initiation of DNA replication, and as an overall regulator of the chromosome replication and cell division cycles of E. coli, is discussed in view of these results.