Small Nucleolar RNA (snoRNA) As the name suggests, these small (60–300 nucleotides) RNAs are found in the nucleolus where they are responsible for several functions: Some participate in making ribosomes by helping to cut up the large RNA precursor of the 28S, 18S, and 5.8S molecules. Others chemically modify many of the nucleotides in rRNA, tRNA, and snRNA molecules, e.g., by adding methyl groups to ribose. Some have been implicated in the alternative splicing of pre-mRNA to different forms of mature mRNA. One snoRNA serves as the template for the synthesis of telomeres. In vertebrates, the snoRNAs are made from introns removed during RNA processing .
Posted on: Thu, 19 Sep 2013 11:23:49 +0000
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