Small nucleolar RNA SNORD81

{{Infobox rfam

| Name = Small nucleolar RNA SNORD81

| image = RF00136.jpg

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| caption = Predicted secondary structure and sequence conservation of SNORD81

| Symbol = SNORD81

| AltSymbols = U81

| Rfam = RF00136

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| RNA_type = Gene; snRNA; snoRNA; CD-box

| Tax_domain = Eukaryota

| GO = {{GO|0006396}} {{GO|0005730}}

| SO = {{SO|0000593}}

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In molecular biology, U81 (also sometimes called Z23 snoRNA) is a member of the C/D class of snoRNA which contain the C (UGAUGA) and D (CUGA) box motifs. U81 acts as a guanine methylation guide and is found in intron 11 of the gas5 gene in mammals.{{cite journal | vauthors = Smith CM, Steitz JA | title = Classification of gas5 as a multi-small-nucleolar-RNA (snoRNA) host gene and a member of the 5'-terminal oligopyrimidine gene family reveals common features of snoRNA host genes | journal = Molecular and Cellular Biology | volume = 18 | issue = 12 | pages = 6897–909 | date = December 1998 | pmid = 9819378 | pmc = 109273 | doi = 10.1128/mcb.18.12.6897 }}