Muth G W, Thompson C M, Hill W E
Department of Chemistry, The University of Montana, Missoula, MT 59812, USA.
Nucleic Acids Res. 1999 Apr 15;27(8):1906-11. doi: 10.1093/nar/27.8.1906.
Studying the intricate folding of rRNA within the ribosome remains a complex problem. Phenanthroline-Cu(II) complexes cleave phosphodiester bonds in rRNA in specific regions, apparently especially where the rRNA structure is constrained in some fashion. We have introduced phenanthroline-copper complexes into 50S Escherichia coli ribosomal subunits and shown specific cleavages in the regions containing nucleotides 60-66 and 87-100. This specificity of cleavage is reduced when the ribosome is heated to 80 degrees C and reduced to background when the ribosomal proteins are extracted and the cleavage repeated on protein-free 23S rRNA. It has been suggested that nucleotides 60-66 and 87-95 in E.coli 23S rRNA are involved in a putative pseudoknot structure, which is supported by covariance data. The paired cleavages of nearly equal intensity of these two regions, when in the ribosome, may further support the existence of a pseudoknot structure in the 100 region of 23S rRNA.
研究核糖体中rRNA的复杂折叠仍然是一个复杂的问题。邻菲罗啉 - 铜（II）配合物能在rRNA的特定区域切割磷酸二酯键，显然特别是在rRNA结构以某种方式受到限制的地方。我们已将邻菲罗啉 - 铜配合物引入50S大肠杆菌核糖体亚基，并在含有核苷酸60 - 66和87 - 100的区域显示出特异性切割。当核糖体加热到80摄氏度时，这种切割特异性降低，而当提取核糖体蛋白并在无蛋白的23S rRNA上重复切割时，切割特异性降至背景水平。有人提出，大肠杆菌23S rRNA中的核苷酸60 - 66和87 - 95参与了一种假定的假结结构，这得到了共变数据的支持。当在核糖体中时，这两个区域几乎强度相等的配对切割可能进一步支持23S rRNA 100区域存在假结结构。
