O-methyltransferase

O-methyltransferase (OMT) is a type of enzyme that catalyzes the transfer of a methyl group from S-adenosyl methionine (SAM) to a specific substrate. This process is known as methylation. O-methyltransferases are found in a wide range of organisms, including bacteria, plants, and animals, and play a crucial role in many biological processes.

Function

O-methyltransferases are involved in the methylation of a variety of substrates, including proteins, nucleic acids, and small molecules. This methylation can have a wide range of effects, depending on the substrate and the specific location of the methylation. For example, methylation of DNA can affect gene expression, while methylation of proteins can alter their function or localization.

In addition to their role in methylation, some O-methyltransferases also have other functions. For example, some are involved in the synthesis of secondary metabolites, which are small molecules that are not necessary for the basic metabolic processes of an organism, but can have important roles in interactions with the environment or other organisms.

Structure

O-methyltransferases are typically composed of a single polypeptide chain, which folds into a specific three-dimensional structure. The active site of the enzyme, where the methylation reaction takes place, is usually located in a cleft or pocket in this structure. The structure of the enzyme can vary depending on the specific substrate it acts on.

Clinical significance

Alterations in the function of O-methyltransferases can have significant clinical implications. For example, mutations in the genes encoding these enzymes can lead to diseases such as cancer, neurodegenerative diseases, and cardiovascular diseases. In addition, some drugs work by inhibiting the activity of specific O-methyltransferases, making these enzymes important targets for drug discovery and development.

File:O-methyltransferase.png

Structure of an O-methyltransferase enzyme.

See also

• Methyltransferase
• S-adenosyl methionine
• Methylation

References

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