protein C-terminal S-isoprenylcysteine carboxyl O-methyltransferase activity

Definition

Target type: molecularfunction

Catalysis of the reaction: S-adenosyl-L-methionine + protein C-terminal S-farnesyl-L-cysteine = S-adenosyl-L-homocysteine + protein C-terminal S-farnesyl-L-cysteine methyl ester. [EC:2.1.1.100]

C-terminal S-isoprenylcysteine carboxyl O-methyltransferase activity is an enzymatic function responsible for the final step in the post-translational modification of a specific class of proteins. This modification, known as prenylation, involves the attachment of a 15-carbon isoprenoid lipid (farnesyl or geranylgeranyl) to a cysteine residue near the C-terminus of the protein.

The enzyme catalyzes the transfer of a methyl group from S-adenosyl methionine (SAM) to the carboxyl group of the isoprenylated cysteine residue. This methylation event plays a critical role in the proper localization and function of many proteins, particularly those involved in signal transduction, membrane association, and protein-protein interactions.

Specifically, methylation of the isoprenyl group increases the hydrophobicity of the protein, promoting its interaction with the cell membrane. This interaction can be further stabilized by other protein-protein interactions, leading to the formation of multi-protein complexes.

In essence, C-terminal S-isoprenylcysteine carboxyl O-methyltransferase activity acts as a molecular switch, regulating the localization and activity of a diverse array of proteins by modifying their interactions with the cellular environment.'
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Proteins (1)

Compounds (2)