Electron microscopic mapping of secondary structures in bacterial 16S and 23S ribosomal ribonucleic acid and 30S precursor ribosomal ribonucleic acid
Electron microscopic mapping of secondary structures in bacterial 16S and 23S ribosomal ribonucleic acid and 30S precursor ribosomal ribonucleic acid
复制标题
细菌 16S 和 23S 核糖体核糖核酸和 30S 前体核糖体核糖核酸二级结构的电子显微镜图谱
DOI：
10.1128/jb.141.1.365-373.1980
复制
发表时间：
1980
影响因子：
3.2
通讯作者：
A. Bassel
中科院分区：
文献类型：
--
作者：
T. Edlind;A. Bassel
电子显微镜显示部分变性的大肠杆菌16S和23S核糖体核糖核酸(RRNA)具有可重复性的二级结构模式。当用50%甲酰胺-100 mM醋酸铵制备时，16S rRNA包含两个小发夹，出现在所有分子中的50%以上。观察到3个开环，频率低于25%。相比之下，23S rRNA在75%以上的分子中包含一个末端开环和两个额外的大结构。这些二级结构模式在铜绿假单胞菌的16S和23S rRNA中是保守的。核糖核酸酶III缺陷突变株AB105的30S前体rRNA在70%甲酰胺-100 mM醋酸铵中部分变性后绘制了二级结构图。在16S和23S rRNA二级结构模式上叠加了两个大的开环。这些环是在前体上发现的最常见的结构，它们的茎与核糖核酸酶III的裂解位点重合。16S和23S rRNA的二级结构模式从它们在30S前体rRNA中的相对位置确定为暂定的5‘-3取向。讨论了二级结构与核糖体蛋白结合和核糖核酸酶III裂解的关系。
Electron microscopy revealed reproducible secondary structure patterns within partially denatured 16S and 23S ribosomal ribonucleic acid (rRNA) from Escherichia coli. When prepared with 50% formamide-100 mM ammonium acetate, 16S rRNA included two small hairpins that appeared in over 50% of all molecules. Three open loops were observed with frequencies of less than 25%. In contrast, 23S rRNA included a terminal open loop and two additional large structures in over 75% of all molecules. These secondary structure patterns were conserved in the 16S and 23S rRNA from Pseudomonas aeruginosa. The secondary structure of the 30S precursor rRNA from the ribonclease III-deficient E. coli mutant AB105 was mapped after partial denaturation in 70% formamide-100 mM ammonium acetate. Two large open loops were superimposed on the 16S and 23S rRNA secondary structure patterns. These loops were the most frequent structures found on the precursor, and their stems coincided with ribonuclease III cleavage sites. A tentative 5'-3 orientation was determined for the secondary structure patterns of 16S and 23S rRNA from their relative locations within 30S precursor rRNA. The relation of secondary structure to ribosomal protein binding and ribonuclease III cleavage is discussed.