REQUIREMENT FOR THE REPLICATION PROTEIN SSB IN HUMAN DNA EXCISION REPAIR
REQUIREMENT FOR THE REPLICATION PROTEIN SSB IN HUMAN DNA EXCISION REPAIR
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DOI：
10.1038/349538a0
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发表时间：
1991-02-07
期刊：
影响因子：
64.8
通讯作者：
WOOD, RD
中科院分区：
文献类型：
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作者：
COVERLEY, D;KENNY, MK;WOOD, RD
复制和修复是维持遗传物质连续性的基本过程。猴病毒40（SV 40）DNA复制的解剖导致了许多真核复制蛋白的鉴定，但DNA切除修复的多酶过程的生物化学还不太清楚。SV 40 DNA在体外保守复制绝对需要的一种蛋白质是人单链DNA结合蛋白（SSB，也称为RF-A和RP-A）1-3。SSB由相对分子质量为70，000、34，000和13，000的三种多肽组成，并与T抗原和拓扑异构酶一起作用以解开DNA，从而允许其他复制蛋白进入。人SSB还可以刺激聚合酶-α和δ的活性，表明在DNA复制期间的延伸中的进一步作用4-6。我们现在已经发现了人SSB在DNA切除修复中的作用，使用可以在体外进行核苷酸切除修复的无细胞系统7。抗人SSB单克隆抗体对紫外线或乙酰氨基芴损伤的质粒分子的DNA修复产生广泛的抑制作用。添加纯化的SSB逆转了这种抑制作用，并通过增加修复事件的数量进一步刺激修复合成。这些结果表明，哺乳动物DNA复制蛋白也是修复所必需的。
REPLICATION and repair are essential processes that maintain the continuity of the genetic material. Dissection of simian virus 40 (SV40) DNA replication has resulted in the identification of many eukaryotic replication proteins, but the biochemistry of the multienzyme process of DNA excision repair is less well defined. One protein that is absolutely required for semiconservative replication of SV40 DNA in vitro is human single-stranded DNA-binding protein (SSB, also called RF-A and RP-A) 1-3. SSB consists of three polypeptides of relative molecular mass 70,000, 34,000 and 13,000, and acts with T antigen and topoisomerases to unwind DNA, allowing the access of other replication proteins. Human SSB can also stimulate the activity of polymerases- alpha and delta, suggesting a further role in elongation during DNA replication 4-6. We have now found a role for human SSB in DNA excision repair using a cell-free system that can carry out nucleotide excision repair in vitro 7. Monoclonal antibodies against human SSB caused extensive inhibition of DNA repair in plasmid molecules damaged by ultraviolet light or acetylaminofluorene. Addition of purified SSB reversed this inhibition and further stimulated repair synthesis by increasing the number of repair events. These results show that a mammalian DNA replication protein is also essential for repair.