Ganot P, Bortolin M L, Kiss T
Laboratoire de Biologie Moléculaire du CNRS, Université Paul Sabatier, Toulouse, France.
Cell. 1997 May 30;89(5):799-809. doi: 10.1016/s0092-8674(00)80263-9.
During the nucleolar maturation of eukaryotic ribosomal RNAs, many selected uridines are converted into pseudouridine by a thus far undefined mechanism. The nucleolus contains a large number of small RNAs (snoRNAs) that share two conserved sequence elements, box H and ACA. In this study, we demonstrate that site-specific pseudouridylation of rRNAs relies on short ribosomal signal sequences that are complementary to sequences in box H/ACA snoRNAs. Genetic depletion and reconstitution studies on yeast snR5 and snR36 snoRNAs demonstrate that box H/ACA snoRNAs function as guide RNAs in rRNA pseudouridylation. These results define a novel function for snoRNAs and further reinforce the idea that base pairing is the most common way to obtain specific substrate-"enzyme" interactions during rRNA maturation.
在真核生物核糖体RNA的核仁成熟过程中，许多选定的尿苷通过一种迄今尚未明确的机制转化为假尿苷。核仁包含大量共享两个保守序列元件（盒H和ACA）的小RNA（snoRNA）。在本研究中，我们证明rRNA的位点特异性假尿苷化依赖于与盒H/ACA snoRNA中的序列互补的短核糖体信号序列。对酵母snR5和snR36 snoRNA的基因缺失和重组研究表明，盒H/ACA snoRNA在rRNA假尿苷化中作为引导RNA发挥作用。这些结果定义了snoRNA的一种新功能，并进一步强化了碱基配对是rRNA成熟过程中获得特异性底物-“酶”相互作用的最常见方式这一观点。
