PROBING THE STRUCTURE OF MOUSE EHRLICH ASCITES CELL 5.8S, 18S AND 28S RIBOSOMAL-RNA IN-SITU
PROBING THE STRUCTURE OF MOUSE EHRLICH ASCITES CELL 5.8S, 18S AND 28S RIBOSOMAL-RNA IN-SITU
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DOI：
10.1093/nar/22.8.1374
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发表时间：
1994-04-25
影响因子：
14.9
通讯作者：
NYGARD, O
中科院分区：
文献类型：
--
作者：
HOLMBERG, L;MELANDER, Y;NYGARD, O
用硫酸二甲酯和1-环己基-3-吗啉乙基碳二亚胺甲对甲苯磺酸盐对小鼠埃利希腹水瘤18 S、5.8S和28 S核糖体RNA进行化学修饰，原位研究了其二级结构。这些试剂特异性修饰RNA中的未配对碱基。反应性碱基通过引物延伸然后凝胶电泳进行定位。这三种rRNA物质同样可用于修饰，即约10%的核苷酸具有反应性。实验数据支持18 S和5.8/28 S rRNA的理论二级结构模型，因为几乎所有修饰的碱基都位于rRNA的推定单链区域或螺旋区域，这些区域可能会发生动态呼吸。然而，偏离建议的模型中发现18 S和28 S rRNA。在18 S rRNA中，5 '结构域中的一些假定螺旋被单链特异性试剂广泛修饰，如28 S rRNA结构域III中的一个建议螺旋。在小鼠埃利希腹水细胞28 S rRNA中存在的四个真核生物特异性扩增片段中，片段I和III仅部分可用于修饰，而片段II和IV显示出平均至高修饰。
The secondary structure of mouse Ehrlich ascites 18S, 5.8S and 28S ribosomal RNA in situ was investigated by chemical modification using dimethyl sulphate and 1-cyclohexyl-3-(morpholinoethyl) carbodiimide metho-p-toluene sulphonate. These reagents specifically modify unpaired bases in the RNA. The reactive bases were localized by primer extension followed by gel electrophoresis. The three rRNA species were equally accessible for modification i.e. approximately 10% of the nucleotides were reactive. The experimental data support the theoretical secondary structure models proposed for 18S and 5.8/28S rRNA as almost all modified bases were located in putative single-strand regions of the rRNAs or in helical regions that could be expected to undergo dynamic breathing. However, deviations from the suggested models were found in both 18S and 28S rRNA. In 18S rRNA some putative helices in the 5'-domain were extensively modified by the single-strand specific reagents as was one of the suggested helices in domain III of 28S rRNA. Of the four eukaryote specific expansion segments present in mouse Ehrlich ascites cell 28S rRNA, segments I and III were only partly available for modification while segments II and IV showed average to high modification.