Burma D P, Nag B, Tewari D S
Proc Natl Acad Sci U S A. 1983 Aug;80(16):4875-8. doi: 10.1073/pnas.80.16.4875.
Association of the 30S and 50S subunits to generate the 70S ribosomes of Escherichia coli has long been known but the mechanism of this interaction remains obscure. Light-scattering studies indicate that naked 16S and 23S RNAs can also associate under conditions similar to those required for the assembly of ribosomes from the constituent RNAs and proteins. The RNA-RNA association also takes place in the presence of ethanol, which promotes folding of 16S and 23S RNAs into specific compact structures with the morphological features of 30S and 50S ribosomes, respectively. Equimolar amounts of the two RNAs are involved in the association. The formation of a stoichiometric complex was shown by light scattering, sucrose density gradient centrifugation, and composite polyacrylamide/agarose gel electrophoresis. The presence of the two species of RNA in the complex was also shown by gel electrophoresis. The association of naked 16S and 23S RNAs suggests that RNA-RNA interaction may play an important role in the association of 30S and 50S subunits.
30S和50S亚基结合形成大肠杆菌的70S核糖体这一现象早已为人所知,但其相互作用机制仍不清楚。光散射研究表明,在类似于由组成RNA和蛋白质组装核糖体所需的条件下,裸露的16S和23S RNA也能结合。RNA-RNA结合在乙醇存在的情况下也会发生,乙醇能促进16S和23S RNA分别折叠成具有30S和50S核糖体形态特征的特定紧密结构。两种RNA以等摩尔量参与结合。通过光散射、蔗糖密度梯度离心和复合聚丙烯酰胺/琼脂糖凝胶电泳显示形成了化学计量复合物。凝胶电泳也显示复合物中存在这两种RNA。裸露的16S和23S RNA的结合表明RNA-RNA相互作用可能在30S和50S亚基的结合中起重要作用。