rRNA (guanine-N2-)-methyltransferase

rRNA (guanine-N2-)-methyltransferase is a type of enzyme (specifically, a methyltransferase) that catalyzes the transfer of a methyl group to the N2 position of a guanine base within ribosomal RNA (rRNA) molecules. This modification is a post-transcriptional process, meaning it occurs after the rRNA molecule has been synthesized from its DNA template.

These enzymes play a critical role in ribosome biogenesis and function. The methylation of guanine at the N2 position can influence the structure, stability, and interactions of rRNA within the ribosome. This, in turn, can affect the efficiency and accuracy of protein synthesis. Different rRNA (guanine-N2-)-methyltransferases may target specific guanine residues within the rRNA molecule, leading to diverse functional consequences.

The precise effects of guanine-N2 methylation on ribosome function are still being investigated, but it is known to be important for proper ribosome assembly, translation fidelity, and cellular response to stress. Defects in rRNA (guanine-N2-)-methyltransferases or aberrant methylation patterns have been linked to various diseases, including cancer and developmental disorders, highlighting the significance of this enzymatic activity in cellular health.

The enzyme typically utilizes a methyl donor, such as S-adenosyl-L-methionine (SAM), which provides the methyl group that is transferred to the guanine base. The reaction results in the formation of S-adenosyl-L-homocysteine (SAH) as a byproduct. The enzyme's activity is usually highly specific, targeting only certain guanine residues within the rRNA molecule.