Shpanchenko O V, Zvereva M I, Dontsova O A, Nierhaus K H, Bogdanov A A
Department of Chemistry, Moscow State University, Russian Federation.
FEBS Lett. 1996 Sep 23;394(1):71-5. doi: 10.1016/0014-5793(96)00872-1.
5S ribosomal RNA forms stable specific complexes with ribosomal proteins L18, L25 and L5. In this work, interaction of phosphate residues of E. coli 5S rRNA within 5S rRNA-protein complexes has been studied. For this purpose 5S rRNA with statistically distributed phosphorothioate residues has been used for complex formation and the accessibility of phosphorothioates to iodine cleavage in the complex and in the free state has been studied. In free 5S rRNA, the phosphate residue at A73 was partially protected, probably due to being involved in the organization of the spatial structure of 5S rRNA. This protection is stronger in the complex with three proteins when the 5S rRNA structure is stabilized. In the 5S rRNA-L18 complex only two phosphate groups, G7 and A34, were protected. L25 in a complex with 5S rRNA protects large numbers of phosphorothioate groups concentrating in two clusters, indicating the possibility of two binding sites for this protein on 5S rRNA. The protection pattern differs from that for individual proteins because of the possible rearrangement of the structure.
5S核糖体RNA与核糖体蛋白L18、L25和L5形成稳定的特异性复合物。在这项工作中，研究了5S核糖体RNA-蛋白质复合物中大肠杆菌5S rRNA磷酸残基的相互作用。为此，使用具有统计分布硫代磷酸酯残基的5S rRNA进行复合物形成，并研究了复合物和游离状态下硫代磷酸酯对碘裂解的可及性。在游离的5S rRNA中，A73处的磷酸残基受到部分保护，这可能是由于其参与了5S rRNA空间结构的组织。当5S rRNA结构稳定时，在与三种蛋白质形成的复合物中这种保护作用更强。在5S rRNA-L18复合物中，只有两个磷酸基团G7和A34受到保护。与5S rRNA形成复合物的L25保护大量硫代磷酸酯基团，这些基团集中在两个簇中，表明该蛋白质在5S rRNA上可能有两个结合位点。由于结构可能发生重排，保护模式与单个蛋白质的不同。
