Eliceiri G L
Department of Pathology, Saint Louis University School of Medicine, St. Louis, Missouri 63104-1028, USA.
Cell Mol Life Sci. 1999 Oct 1;56(1-2):22-31. doi: 10.1007/s000180050003.
Many small RNA species associate with the nucleolar structure. Some of these small nucleolar RNAs (snoRNAs) are required for cleavage processing of ribosomal RNA precursors. There are many pseudouridine residues and methylated riboses in mature ribosomal RNA. For most, if not all, of these modifications, each site is selected by base pairing with a specific snoRNA species. Some snoRNAs are needed for the 2'-O-ribose methylation of at least one spliceosomal small nuclear RNA. Many snoRNAs, particularly in yeast, are generated from independent transcription units. Most vertebrate snoRNAs are produced by processing of introns from protein-coding transcripts. Some snoRNAs are made by processing of introns from non-protein-coding transcripts.
许多小RNA种类与核仁结构相关联。其中一些小核仁RNA（snoRNA）是核糖体RNA前体切割加工所必需的。成熟核糖体RNA中有许多假尿苷残基和甲基化核糖。对于这些修饰中的大多数（如果不是全部的话），每个位点都是通过与特定的snoRNA种类进行碱基配对来选择的。一些snoRNA是至少一种剪接体小核RNA的2'-O-核糖甲基化所必需的。许多snoRNA，特别是在酵母中，由独立的转录单元产生。大多数脊椎动物的snoRNA是通过加工蛋白质编码转录本中的内含子产生的。一些snoRNA是通过加工非蛋白质编码转录本中的内含子产生的。
