The translocating RecBCD enzyme stimulates recombination by directing RecA protein onto ssDNA in a chi-regulated manner
The translocating RecBCD enzyme stimulates recombination by directing RecA protein onto ssDNA in a chi-regulated manner
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DOI：
10.1016/s0092-8674(00)80315-3
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发表时间：
1997-07-11
期刊：
影响因子：
64.5
通讯作者：
Kowalczykowski, SC
中科院分区：
文献类型：
--
作者：
Anderson, DG;Kowalczykowski, SC
大肠杆菌中的双链 DNA 断裂修复和同源重组由 RecBCD 酶启动，该酶解旋并同时降解双链 DNA 末端的 DNA。这一过程是由顺式作用 DNA 元件（称为 chi 位点）刺激的。使用体外配对和核酸酶保护测定，我们证明由 chi 激活的易位 RecBCD 酶协调同源配对蛋白 RecA 优先加载到 chi 下游所得的单链 DNA 上。这促进了 RecA 蛋白的装载，导致体外重组反应的效率和速率显着增加，并为 chi 刺激体内重组和修复提供了解释。
Double-stranded DNA break repair and homologous recombination in E. coli are initiated by the RecBCD enzyme, which unwinds and simultaneously degrades DNA from a double-stranded DNA end. This process is stimulated by cis-acting DNA elements, known as chi sites. Using both in vitro pairing and nuclease protection assays, we demonstrate that the translocating RecBCD enzyme, which has been activated by chi, coordinates the preferential loading of the homologous pairing protein, RecA, onto the resultant single-stranded DNA downstream of chi. This facilitated loading of RecA protein results in a substantial increase in both the efficiency and rate of in vitro recombination reactions and offers an explanation for stimulation of recombination and repair in vivo by chi.