Primosome assembly requirement for replication restart in the Escherichia coli holDG10 replication mutant
Primosome assembly requirement for replication restart in the Escherichia coli holDG10 replication mutant
复制标题
DOI：
10.1046/j.1365-2958.2002.02913.x
复制
发表时间：
2002-05-01
影响因子：
3.6
通讯作者：
Michel, B
中科院分区：
文献类型：
--
作者：
Flores, MJ;Ehrlich, SD;Michel, B
在这份报告中，我们研究的作用，在一个菌株中，复制停滞的频率增加，因为在复制蛋白的突变的前引发体蛋白。使用holdD（G10）突变体，其中复制重启涉及复制叉逆转。正如预期的那样，PriA的primosome装配功能是holdD（G10）突变体生长所必需的。priA300突变，它失活的唯一解旋酶功能的PriA在体外，和priB失活强烈损害生存能力。相反，priC失活没有影响。因此，PriB比PriC对体内PriA依赖的复制叉重启更重要。功能突变dnaC809的获得仅在一定程度上恢复了holD（G10）priA和holD（G10）priB突变体的活力。dnaC809 820双突变恢复了缺乏PriA或PriB的holdD（G10）突变体的完全活力。与holD（G10）单突变体类似，holD（G10）priA dnaC809 820菌株的活力依赖于RecBC，表明使用dnaC809 820突变促进启动子体组装不允许绕过复制叉逆转。
In this report, we study the role of pre-primosome proteins in a strain in which the frequency of replication arrest is increased because of a mutation in a replication protein. The holD(G10) mutant was used, in which replication restart involves replication fork reversal. As expected, PriA primosome assembly function is essential for growth of the holD(G10) mutant. The priA300 mutation, which inactivates only the helicase function of PriA in vitro, and priB inactivation strongly impair viability. In contrast, priC inactivation has no effect. Therefore, PriB is more important than PriC for PriA-dependent replication fork restart in vivo. The gain of function mutation dnaC809 restores the viability of holD(G10) priA and holD(G10) priB mutants only to some extent. The dnaC809 820 double mutation restores full viability to the holD(G10) mutant lacking either PriA or PriB. Similarly to the holD(G10) single mutant, the holD(G10) priA dnaC809 820 strain is dependent on RecBC for viability, indicating that facilitating primosome assembly using the dnaC809 820 mutation does not allow bypass of replication fork reversal.