Superhelicity induces hypersensitivity of a human polypyrimidine . polypurine DNA sequence in the human alpha 2-alpha 1 globin intergenic region to S1 nuclease digestion--high resolution mapping of the clustered cleavage sites.
Superhelicity induces hypersensitivity of a human polypyrimidine . polypurine DNA sequence in the human alpha 2-alpha 1 globin intergenic region to S1 nuclease digestion--high resolution mapping of the clustered cleavage sites.
复制标题
超螺旋性会引起人类多聚嘧啶的超敏反应。
DOI：
10.1093/nar/11.22.7899
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发表时间：
1983
影响因子：
14.9
通讯作者：
Shen,CK
中科院分区：
文献类型：
--
作者：
Shen,CK
用核酸酶S1在体外对含有成人α-珠蛋白基因区的超螺旋重组DNA进行了探针检测。琼脂糖凝胶电泳显示，在人DNA的6 kb和pBR 322序列的4kb内，SI仅产生一个主要的双链切割，而高分辨率凝胶分析揭示，人成人α-珠蛋白基因区中独特的SI-超敏感位点实际上包含超过15个紧密间隔在一起的真实SI切割位点。这里使用的映射方法在核苷酸序列水平上定位两条DNA链上的特异性SI切割位点。有趣的是，这些位点中的大多数被定位在富含GC（66%）的多嘧啶多嘌呤DNA的90 bp延伸段内，其位于α 1-珠蛋白基因上游1060至1150 bp处。这些结果提供了在超螺旋应变下在特定DNA序列内诱导的双链S1切割位点的第一高分辨率图。这些网站映射的分布和相对切割频率是一致的滑动机制，其中简单的重复序列被组织成碱基错配双链体的超螺旋DNA。
Supercoiled recombinant DNAs containing the human adult a-globin gene region have been probed with nuclease SIin vitro. While agarose gel electrophoresis showed only one predominant, double-stranded cleavage generated by SI within 6 kb of human DNA and 4 kb of pBR322 sequence, a high resolution gel analysis reveals that the unique Sl-hypersensitive locus in the human adult a-globin gene region actually contains more than 15 authenti SI cleavage sites closely spaced together. The mapping approach used here locates the specific SI cleavage sites on both DNA strands at the nucleotide sequence level. Interestingly, most of these sites are mapped within a 90 bp stretch of GC-rich (66%) polypyrimidine'polypurine DNA that is located 1060 to 1150 bp upstream from the al-globin gene. These results provide the first high resolution map of double-stranded Sl-cleavage sites induced within a specific DNA sequence under supercoil strain. The distribution and relative cutting frequencies of these sites mapped are consistent with a slippage mechanism in which the simple repeating sequences are organized into base-mismatched duplex on supercoiled DNA.