RNA nuclease activity

Definition

Target type: molecularfunction

Catalysis of the hydrolysis of phosphodiester bonds in chains of RNA. [GOC:mah, ISBN:0198547684]

RNA nucleases are a diverse group of enzymes that catalyze the cleavage of phosphodiester bonds within RNA molecules. This activity is essential for various cellular processes, including:

* **RNA processing:** RNA nucleases play a crucial role in the maturation of RNA transcripts, removing non-coding sequences (introns) and processing precursor molecules into functional forms. For example, the 5' cap and 3' poly(A) tail of eukaryotic messenger RNA (mRNA) are added by specific nucleases.
* **RNA degradation:** Nucleases are involved in the breakdown of RNA molecules that are no longer needed, such as damaged or misfolded transcripts. This degradation process is essential for maintaining the integrity of the transcriptome and preventing the accumulation of harmful RNA molecules.
* **Regulation of gene expression:** RNA nucleases can regulate gene expression by degrading specific transcripts or by modifying their stability. This regulation can occur at various levels, including transcription, translation, and RNA transport.
* **Viral defense:** In eukaryotes, RNA nucleases serve as an important line of defense against viral infection by degrading viral RNA molecules.
* **RNA interference (RNAi):** RNA nucleases are key components of the RNAi pathway, which is a powerful gene silencing mechanism. RNAi utilizes small interfering RNAs (siRNAs) or microRNAs (miRNAs) to target and degrade specific mRNAs.

The mechanisms by which RNA nucleases cleave RNA molecules can vary depending on the specific enzyme. Some nucleases employ a hydrolytic mechanism, breaking the phosphodiester bond by adding a water molecule, while others utilize a metal-dependent mechanism that requires the presence of a metal ion, such as magnesium.

In summary, RNA nucleases are essential enzymes with diverse functions that are critical for maintaining cellular homeostasis and regulating gene expression.'
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Proteins (5)

Compounds (16)