Luniak V V, Timchenko N A
Mol Biol (Mosk). 1994 Jul-Aug;28(4):822-31.
Earlier, a number of DNA fragments were identified in the complex form of DNA polymerase alpha. One of them, DARC146, can support autonomous replication in mammalian cells. We have subcloned 146 bp from DARC146 (here called DARC146). This fragment has an ability to replicate autonomously in mammalian cells. This ability permits one to speak about DARC146 as a putative replication origin. From this conclusion, we suggest that all signals for initiation of DNA synthesis are located on the nucleotide sequence under study. Here, we have shown that the nuclear extract contains four polypeptides binding specifically to synthetic oligonucleotides covering the AT-rich region of the DARC146 sequence. The first protein is Oct-1, a nuclear transcription-replication factor. The second protein (named p65) binds to the TCTCTTA site of the DARC146 nucleotide sequence. There are two sites for Oct-1 protein and two sites for p65 in the DARC146 fragment. Octamer motifs and sites for p65 are located tandemly side by side. Moreover, we identified 28kDa polypeptide from nuclear matrix which bound to DARC146. Based upon the data presented, we suggest a hypothetical model of the pre-initiation state of the DARC146 sequence.
早些时候，在DNA聚合酶α的复杂形式中鉴定出了一些DNA片段。其中一个片段DARC146能够支持在哺乳动物细胞中的自主复制。我们从DARC146中克隆了146bp（此处称为DARC146）。该片段具有在哺乳动物细胞中自主复制的能力。这种能力使人们可以将DARC146视为一个假定的复制起点。基于这一结论，我们认为DNA合成起始的所有信号都位于所研究的核苷酸序列上。在这里，我们已经表明核提取物中含有四种与覆盖DARC146序列富含AT区域的合成寡核苷酸特异性结合的多肽。第一种蛋白质是Oct-1，一种核转录-复制因子。第二种蛋白质（命名为p65）与DARC146核苷酸序列的TCTCTTA位点结合。在DARC146片段中有两个Oct-1蛋白结合位点和两个p65结合位点。八聚体基序和p65位点并排串联排列。此外，我们从核基质中鉴定出了与DARC146结合的28kDa多肽。基于所呈现的数据，我们提出了DARC146序列起始前状态的假设模型。
