RNA exonuclease activity

Definition

Target type: molecularfunction

Catalysis of the sequential cleavage of mononucleotides from a free 5' or 3' terminus of an RNA molecule. [GOC:mah, ISBN:0198547684]

RNA exonuclease activity is a crucial molecular function responsible for the degradation of RNA molecules by removing nucleotides from the ends of the RNA chain. This activity is essential for various cellular processes, including:
- **RNA processing:** Exonucleases play a role in the maturation of messenger RNA (mRNA) by removing extra nucleotides from the 5’ and 3’ ends.
- **RNA surveillance:** They help degrade aberrant or damaged RNA molecules that could disrupt cellular function.
- **Regulation of gene expression:** Exonucleases can control the stability and translation of mRNA molecules by degrading them.
- **Viral replication:** Some viruses rely on exonuclease activity to replicate their genomes.
- **Immune system:** Exonucleases are involved in the degradation of viral RNA during the immune response.
- **DNA replication and repair:** Some exonucleases possess dual activity and can also degrade DNA, playing a role in DNA replication and repair.

There are two main types of RNA exonucleases:
- **5’-3’ exonucleases:** These enzymes remove nucleotides from the 5’ end of an RNA molecule.
- **3’-5’ exonucleases:** These enzymes remove nucleotides from the 3’ end of an RNA molecule.

The mechanism of action involves the enzyme binding to the end of the RNA molecule and cleaving the phosphodiester bond between the last nucleotide and the penultimate nucleotide. This process is often coupled with the release of the cleaved nucleotide. The specific mechanism and substrate specificity vary depending on the enzyme and its cellular context.
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Proteins (2)

Compounds (2)