RNA methyltransferase activity

Definition

Target type: molecularfunction

Catalysis of the transfer of a methyl group from a donor to a nucleoside residue in an RNA molecule. [GOC:mah]

RNA methyltransferases are a diverse group of enzymes that catalyze the transfer of a methyl group from a donor molecule, typically S-adenosyl methionine (SAM), to a specific nucleotide base in RNA. This methylation process can occur at various positions within the RNA molecule, including the nitrogenous base, the ribose sugar, or the phosphate backbone. The specific site and type of methylation are determined by the specific RNA methyltransferase enzyme.

RNA methylation plays crucial roles in a wide range of cellular processes, including:

* **Gene regulation:** Methylation of RNA can alter its stability, translation efficiency, and interaction with other proteins, thereby affecting gene expression.
* **RNA processing:** Methylation can influence RNA splicing, capping, and polyadenylation, key steps in RNA maturation.
* **RNA structure and function:** Methylation can contribute to the formation of specific RNA secondary and tertiary structures, influencing its biological activity.
* **Viral infection:** Some viruses encode their own RNA methyltransferases that modify viral RNA, potentially impacting host immune responses.
* **Immune response:** Methylation of certain RNAs can regulate the activity of immune cells.

The molecular mechanism of RNA methylation involves a series of steps:

1. **Binding of the RNA methyltransferase to its substrate RNA:** The enzyme recognizes a specific sequence or structure within the RNA molecule.
2. **Binding of SAM:** The donor molecule, SAM, binds to the enzyme's active site.
3. **Transfer of the methyl group:** The enzyme catalyzes the transfer of a methyl group from SAM to the target nucleotide base in RNA.
4. **Release of the methylated RNA and S-adenosyl homocysteine (SAH):** The enzyme releases the modified RNA and the byproduct of the reaction, SAH.

The diverse roles of RNA methylation in cellular processes highlight its importance in maintaining cellular homeostasis and regulating various biological functions. Dysregulation of RNA methylation can lead to disease states, including cancer and developmental disorders.'
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Proteins (1)

Compounds (1)