Mapping of replication initiation sites in the mouse ribosomal gene cluster
Mapping of replication initiation sites in the mouse ribosomal gene cluster
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DOI：
10.1007/bf00352115
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发表时间：
1996-04-01
期刊：
影响因子：
1.6
通讯作者：
Grummt, F
中科院分区：
文献类型：
--
作者：
Gogel, E;Langst, G;Grummt, F
我们已经使用新生链测定分析映射的DNA复制的起始位点在小鼠核糖体基因簇中的核糖体基因的个体拷贝被分开的基因间间隔区。一个双向复制起点（OBR）位于rDNA转录起始位点上游约1.6 kb的3 kb区域内。至少一个额外的起始位点位于转录单位的3'端附近。与转录起始位点处的OBR相邻的是两个扩增促进序列，即，APS 1和APS 2。在两个APS以及OBR区域中均发现核酸酶超敏感位点，从而表明这些序列具有改变的染色质结构。在OBR中发现了一个固有的弯曲区，一个富含嘌呤的元素和其他潜在的起始区成分。
We have used nascent strand determination analysis to map start sites of DNA replication in the mouse ribosomal gene cluster in which individual copies of the ribosomal genes are separated by intergenic spacer regions. One origin of bidirectional replication (OBR) was localized within a 3 kb region centered about 1.6 kb upstream of the rDNA transcription start site. At least one additional initiation site is situated near the 3' end of the transcription unit. Adjacent to the OBR at the transcription start site are located two amplification-promoting sequences, i.e., APS1 and APS2. Nuclease-hypersensitive sites were identified in both of the two APSs as well as in the OBR region, thus indicating that these sequences have an altered chromatin structure. In the OBR an intrinsically bent region, a purine-rich element and other prospective initiation zone components are found.