Distal sequences, but not ori-β/OBR-1, are essential for initiation of DNA replication in the Chinese hamster DHFR origin
Distal sequences, but not ori-β/OBR-1, are essential for initiation of DNA replication in the Chinese hamster DHFR origin
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DOI：
10.1016/s1097-2765(00)80294-4
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发表时间：
1998-12-01
期刊：
影响因子：
16
通讯作者：
Hamlin, JL
中科院分区：
文献类型：
--
作者：
Kalejta, RF;Li, X;Hamlin, JL
在中国仓鼠二氢叶酸还原酶复制起始区，ori-β基因座优先于其他起始位点。为了检验ori-β含有遗传复制因子的假设，我们用粘粒恢复了DHFR基因3'端的缺失，该粘粒提供缺失的序列并同时敲除下游的ori-β基因座。在ori-β基因敲除的细胞系中，复制正常启动，并且DHFR结构域仍在早期S期合成。然而，起始在缺少基因3'端的起始缺失变体中被完全抑制。我们的结论是，ori-β不包含一个必不可少的复制因子，但遥远的序列元素有深远的影响，在这个位点上的起源活动。
In the chinese hamster dihydrofalate reductase replication initiation zone, the ori-beta locus is preferred over other start sites. To test the hypothesis that ori-beta contains a genetic replicator, we restored a deletion in the 3' end of the DHFR gene with a cosmid that provides the missing sequence and simultaneously knocks out the downstream ori-beta locus. Replication initiates normally in ori-beta knockout cell lines, and the DHFR domain is still synthesized in early S phase. However, initiation is completely suppressed in the starting deletion variant lacking the 3' end of the gene. We conclude that ori-beta does not contain an essential replicator, but that distant sequence elements have profound effects on origin activity in this locus.