Back آر أن إيه نويي صغير Arabic SnoRNA German ARN pequeño nucleolar Spanish آرانای کوچک هستکی Persian Petit ARN nucléolaire French ARN nucleolar pequeno Galician SnoRNA HE Mala jezgričina RNK Croatian Small nucleolar RNA Italian 核小体低分子RNA Japanese
In molecular biology, small nucleolar RNAs (snoRNAs) are a class of small RNA molecules that primarily guide chemical modifications of other RNAs, mainly ribosomal RNAs, transfer RNAs and small nuclear RNAs. There are two main classes of snoRNA, the C/D box snoRNAs, which are associated with methylation, and the H/ACA box snoRNAs, which are associated with pseudouridylation. SnoRNAs are commonly referred to as guide RNAs but should not be confused with the guide RNAs that direct RNA editing in trypanosomes or the guide RNAs (gRNAs) used by Cas9 for CRISPR gene editing.