A NOVEL PATHWAY OF DNA END-TO-END JOINING
A NOVEL PATHWAY OF DNA END-TO-END JOINING
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DOI：
10.1016/0092-8674(90)90340-k
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发表时间：
1990-03-23
期刊：
影响因子：
64.5
通讯作者：
VIELMETTER, W
中科院分区：
文献类型：
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作者：
THODE, S;SCHAFER, A;VIELMETTER, W
与非法重组相关的修复机制可以连接终止为突出单链 (PSS) 的非同源 DNA 末端。在这里，我们分析了非洲爪蟾卵提取物中 3'' PSS 末端和各种伙伴末端之间的连接反应。在连接处，3'' PSS 末端通过填充 DNA 合成得以保留，尽管它们的 5'' 凹进末端不能用作引物。从连接到 3'' PSS 末端的伴侣末端进行替代引发似乎不太可能，因为没有检测到单链特异性 DNA 连接酶。我们表明，3'' PSS 末端的填充先于连接，甚至可以在没有任何连接的情况下进行引发。因此，启动需要通过一种新颖的机制精确对准末端对。我们假设这是通过独特的 DNA 结合蛋白实现的，这些蛋白在各种类型的连接反应中对齐末端。
Repair mechanisms related to illegitimate recombination can join nonhomologous DNA ends that terminate as protruding single strands (PSS). Here we analyze in Xenopus egg extracts joining reactions between 3'' PSS terminal and various partner termini. In junctions, 3'' PSS termini are preserved by fill-in DNA synthesis, although their 5'' recessed ends cannot serve as a primer. Alternative priming from a partner terminus ligated to the 3'' PSS end appears unlikely, because no single strand-specific DNA ligases are detectable. We show that fill-in of 3'' PSS termini precedes ligation and can even be primed in the absence of any ligation. Therefore, priming requires precise alignment of terminus pairs by a novel mechanism. We postulate that this is achieved by unique DNA binding proteins that align ends in various types of joining reactions.