SnoRNAmolekyylejä

SnoRNAmolekyylejä, known as small nucleolar RNAs, are a class of non-coding RNA molecules found in the nucleolus of eukaryotic cells. These molecules play a crucial role in the post-transcriptional modification of other RNA molecules, primarily ribosomal RNAs (rRNAs) and transfer RNAs (tRNAs). Their main function is to guide and catalyze the chemical modifications, specifically ribose methylation and pseudouridylation, which are essential for the proper folding and function of these key RNA components.

SnoRNAs are typically transcribed by RNA polymerase II or III and range in size from 60 to 300 nucleotides. They are characterized by conserved sequence elements, including the C and D boxes, which are important for their interaction with proteins and for guiding the modification process. These proteins, along with the snoRNA, form ribonucleoprotein complexes called small nucleolar ribonucleoproteins (snoRNPs).

There are two main types of snoRNAs: C/D box snoRNAs, which guide ribose methylation, and H/ACA box snoRNAs, which guide pseudouridylation. Both types are indispensable for the maturation of functional ribosomes, which are responsible for protein synthesis. Dysregulation or defects in snoRNA function can lead to various cellular abnormalities and have been implicated in the development of certain diseases, including cancer and developmental disorders. Research into snoRNAs continues to uncover their diverse roles in cellular processes beyond RNA modification.