Association of 3'----5' exodeoxyribonuclease activity with DNA replitase complex from S-phase Chinese hamster embryo fibroblast cells.
Association of 3'----5' exodeoxyribonuclease activity with DNA replitase complex from S-phase Chinese hamster embryo fibroblast cells.
复制标题
3----5 外脱氧核糖核酸酶活性与来自 S 期中国仓鼠胚胎成纤维细胞的 DNA 复制酶复合物的关联。
DOI：
10.1016/0014-4827(89)90389-3
复制
发表时间：
1989
影响因子：
3.7
通讯作者：
Reddy,GP
中科院分区：
文献类型：
--
作者：
Hammond,RA;Miller,MR;Gray,MS;Reddy,GP
DNA复制酶被描述为哺乳动物细胞中与DNA前体生物合成和DNA复制相关的酶/蛋白质复合物[Reddy， g.p.v., and Pardee, a.b. (1980)Proc.]。国家的。学会科学。USA77, 3312 - 3316]。我们首次证明了3 ‘→5 ’外脱氧核糖核酸酶活性与复制酶复合体有关。根据其对GMP和丁基苯基脱氧鸟苷三磷酸（BuPdGTP）抑制的敏感性，该外切酶活性高达60%与DNA聚合酶δ相似。通过在体外DNA聚合酶测定系统中分析dTTP向dTMP的转换，也证实了复制酶复合体中3 ‘→5 ’外切酶活性与DNA聚合酶的关联。复制酶复合体中DNA聚合酶活性对BuPdGTP的敏感性与可渗透细胞中DNA复制的敏感性相似，介于BuPdGTP对纯化DNA聚合酶α和δ的抑制之间。这些研究表明，在哺乳动物细胞中，复制酶复合体含有3 ‘→5 ’外切酶活性，与负责细胞核DNA复制的DNA聚合酶活性相关。需要进一步的研究来确定这些活性是否至少部分归因于DNA聚合酶δ。
DNA replitase has been described as a complex of enzymes/proteins that are associated with both DNA precursor biosynthesis and DNA replication in mammalian cells [Reddy, G. P. V., and Pardee, A. B. (1980)Proc. Natl. Acad. Sci. USA77, 3312–3316]. We demonstrate for the first time a 3′ → 5′ exodeoxyribonuclease activity is associated with the replitase complex. As much as 60% of this exonuclease activity was similar to that associated with DNA polymerase δ based upon its sensitivity to inhibition by GMP and by butyl-phenyl-deoxyguanosine triphosphate (BuPdGTP). Association of 3′ → 5′ exonuclease activity with the DNA polymerase in the replitase complex was also demonstrated by analyzing dTTP turnover to dTMP in anin vitroDNA polymerase assay system. The DNA polymerase activity in replitase complex exhibited a sensitivity to BuPdGTP which both was similar to that of DNA replication in permeable cells and was intermediate between the BuPdGTP inhibition of purified DNA polymerases α and δ. These studies suggest that the replitase complex contains 3′ → 5′ exonuclease activity associated with the DNA polymerase activity responsible for nuclear DNA replication in mammalian cells. Further studies are required to determine if these activities are at least partially attributed to DNA polymerase δ.