TRNA (cytosine38-C5)-methyltransferase

TRNA (cytosine38-C5)-methyltransferase is an enzyme that catalyzes the addition of a methyl group to the 5-carbon position of cytosine at position 38 in transfer RNA (tRNA) molecules. This modification, known as 5-methylcytosine (m5C), is a post-transcriptional modification that plays a role in tRNA stability, structure, and function.

Specifically, these enzymes belong to the family of methyltransferases, which are enzymes that catalyze the transfer of a methyl group from a donor molecule, typically S-adenosyl-L-methionine (SAM), to an acceptor molecule. In this case, the acceptor molecule is the cytosine base at position 38 of a specific tRNA molecule.

The enzyme ensures that the methylation occurs specifically at cytosine 38 within the tRNA molecule. This site-specific methylation is crucial for the correct function of the tRNA.

The biological significance of m5C modification at position 38 of tRNA is varied and can depend on the specific tRNA species and organism. It is thought to influence the folding and stability of the tRNA molecule, potentially affecting its interaction with ribosomes and other cellular components involved in protein synthesis. The methylation may also contribute to codon recognition accuracy and translational efficiency. Dysregulation of tRNA methylation has been implicated in various diseases, including cancer.

Different organisms may possess different tRNA (cytosine38-C5)-methyltransferases, which might exhibit variations in substrate specificity or regulatory mechanisms. Understanding the specific roles and regulation of these enzymes is an active area of research.