box C/D sno(s)RNA 3'-end processing

Definition

Target type: biologicalprocess

Any process involved in forming the mature 3' end of a box C/D RNA molecule. [GOC:krc]

Box C/D snoRNAs are small nucleolar RNAs that guide the site-specific 2'-O-methylation of ribosomal RNAs (rRNAs). The 3'-end processing of these snoRNAs is a crucial step in their maturation and function. This process is carried out by a complex machinery involving several factors, including the RNase MRP, a ribonucleoprotein complex that contains both RNA and protein components.

The 3'-end processing of box C/D snoRNAs begins with the recognition of a specific sequence motif located at the 3'-end of the precursor snoRNA. This motif, known as the "box D' element," is typically located 10-15 nucleotides upstream of the mature 3'-end.

RNase MRP then cleaves the precursor snoRNA at the 3'-end of the box D' element, releasing the mature snoRNA. This cleavage is highly specific and is guided by the interaction between the box D' element and the RNA component of RNase MRP.

The precise mechanism of the cleavage reaction remains under investigation, but it likely involves a two-step process:

1. Recognition and binding of the box D' element to the RNA component of RNase MRP.
2. Cleavage of the precursor snoRNA by the catalytic site of RNase MRP.

Following cleavage, the 3'-end of the mature snoRNA may be further processed by other enzymes, such as the 3'-5' exonuclease Rrp6. These additional steps ensure the precise 3'-end structure required for the proper function of the snoRNA.

The 3'-end processing of box C/D snoRNAs is essential for their correct localization and function. Defects in this process can lead to the accumulation of unprocessed snoRNAs, which can interfere with the proper maturation of ribosomes and result in cellular dysfunction.'
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Proteins (1)

Compounds (1)