Small nucleolar RNA R21 is a non-coding RNA (ncRNA) molecule which functions in the modification of other small nuclear RNAs (snRNAs). This type of modifiying RNA is usually located in the nucleolus of the eukaryotic cell which is a major site of snRNA biogenesis. It is known as a small nucleolar RNA (snoRNA) and also often referred to as a guide RNA. snoRNA R21 belongs to the C/D box class of snoRNAs which contain the conserved sequence motifs known as the C box (UGAUGA) and the D box (CUGA). Most of the members of the box C/D family function in directing site-specific 2'-O-methylation of substrate RNAs. Plant snoRNA R21 was identified in a screen of Arabidopsis thaliana .
Famous quotes containing the word small:
“What strikes me as odd now is how much my father managed to get across to me without those heart-to-hearts which I’ve read about fathers and sons having in the study or in the rowboat or in the car.... Somehow I understood completely how he expected me to behave, in small matters as well as large, even though I can’t remember being given any lectures about it beyond the occasional, undramatic “You might as well be a mensch.””
—Calvin Trillin (20th century)