In the simian virus 40 in vitro replication system, start site selection by the polymerase alpha-primase complex is not significantly altered by changes in the concentration of ribonucleotides.
In the simian virus 40 in vitro replication system, start site selection by the polymerase alpha-primase complex is not significantly altered by changes in the concentration of ribonucleotides.
复制标题
在猿猴病毒40体外复制系统中，聚合酶α-引物酶复合物的起始位点选择不会因核糖核苷酸浓度的变化而显着改变。
DOI：
10.1128/jvi.75.14.6392-6401.2001
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发表时间：
2001
影响因子：
5.4
通讯作者：
Bullock,PeterA
中科院分区：
文献类型：
--
作者：
Purviance,JohnD;Prack,AndreaE;Barbaro,BrettA;Bullock,PeterA
猿猴病毒 40 (SV40) 体外复制系统先前被用来证明人类聚合酶 (Pol) α-引物酶复合物优先在富含嘧啶的三核苷酸序列处启动 DNA 合成。然而，据报道，在某些条件下，三磷酸核苷 (NTP) 浓度在确定真核引物酶起始合成的位置中起着关键作用。因此，我们检查了增加的 NTP 浓度是否会改变启动 SV40 复制的模板位置。我们的研究表明，升高的核糖核苷酸浓度不会显着改变作为起始位点的模板序列。令人相当感兴趣的是，SV40 系统中充当起始位点的序列与充当原核引物酶起始位点的序列相似。还证明，无论反应中存在的核糖核苷酸浓度如何，DNA 合成都会在核心起点之外启动。这些研究提供了额外的证据，证明 Pol α-引物酶复合物只有在产生大量单链 DNA 后才能启动 DNA 合成。
The simian virus 40 (SV40) in vitro replication system was previously used to demonstrate that the human polymerase (Pol) α-primase complex preferentially initiates DNA synthesis at pyrimidine-rich trinucleotide sequences. However, it has been reported that under certain conditions, nucleoside triphosphate (NTP) concentrations play a critical role in determining where eukaryotic primase initiates synthesis. Therefore, we have examined whether increased NTP concentrations alter the template locations at which SV40 replication is initiated. Our studies demonstrate that elevated ribonucleotide concentrations do not significantly alter which template sequences serve as initiation sites. Of considerable interest, the sequences that serve as initiation sites in the SV40 system are similar to those that serve as initiation sites for prokaryotic primases. It is also demonstrated that regardless of the concentration of ribonucleotides present in the reactions, DNA synthesis initiated outside of the core origin. These studies provide additional evidence that the Pol α-primase complex can initiate DNA synthesis only after a considerable amount of single-stranded DNA is generated.