Functional overlap between RecA and MgsA (RarA) in the rescue of stalled replication forks in Escherichia coli
Functional overlap between RecA and MgsA (RarA) in the rescue of stalled replication forks in Escherichia coli
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DOI：
10.1111/j.1365-2443.2005.00831.x
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发表时间：
2005-03
期刊：
影响因子：
2.1
通讯作者：
T. Shibata;T. Hishida;Yoshino Kubota;Yong-Woon Han;H. Iwasaki;H. Shinagawa
中科院分区：
文献类型：
--
作者：
T. Shibata;T. Hishida;Yoshino Kubota;Yong-Woon Han;H. Iwasaki;H. Shinagawa
大肠杆菌RecA蛋白在DNA同源重组、重组修复和挽救停滞或崩溃的复制叉中发挥作用。mgsA （rarA）基因编码高度保守的DNA依赖性atp酶，其酵母同源物MGS1在维持基因组稳定性中起作用。在这项研究中，我们展示了DNA复制过程中mgsA和recA之间的功能关系。与recA单突变体相比，mgsA recA双突变体生长更慢，生存能力更低，但它们对紫外线诱导的DNA损伤同样敏感。mgsA和recA突变导致DNA聚合酶I缺陷细胞死亡，并抑制dnaE486 （Pol III α催化亚基）的温度依赖性生长缺陷。此外，本研究发现的一种新的recA等位基因recAS25P并不弥补ΔmgsA ΔrecA细胞的缓慢生长或polA12 ΔrecA的致死性，而是精通DNA修复、同源重组、SOS诱变和SOS诱导。这些结果表明，RecA和MgsA在挽救停滞的复制叉中具有功能冗余，并且RecA的DNA修复和同源重组功能与其维持复制叉进展的功能是分离的。
Escherichia coli RecA protein plays a role in DNA homologous recombination, recombination repair, and the rescue of stalled or collapsed replication forks. The mgsA (rarA) gene encodes a highly conserved DNA‐dependent ATPase, whose yeast orthologue, MGS1, plays a role in maintaining genomic stability. In this study, we show a functional relationship between mgsA and recA during DNA replication. The mgsA recA double mutant grows more slowly and has lower viability than a recA single mutant, but they are equally sensitive to UV‐induced DNA damage. Mutations in mgsA and recA cause lethality in DNA polymerase I deficient cells, and suppress the temperature‐dependent growth defect of dnaE486 (Pol III α‐catalytic subunit). Moreover, recAS25P, a novel recA allele identified in this work, does not complement the slow growth of ΔmgsA ΔrecA cells or the lethality of polA12 ΔrecA, but is proficient in DNA repair, homologous recombination, SOS mutagenesis and SOS induction. These results suggest that RecA and MgsA are functionally redundant in rescuing stalled replication forks, and that the DNA repair and homologous recombination functions of RecA are separated from its function to maintain progression of replication fork.