Methyltransferase type 11 <p>Methyl transfer from the ubiquitous S-adenosyl-L-methionine (SAM) to either nitrogen, oxygen or carbon atoms is frequently employed in diverse organisms ranging from bacteria to plants and mammals. The reaction is catalyzed by methyltransferases (Mtases) and modifies DNA, RNA, proteins and small molecules, such as catechol for regulatory purposes. The various aspects of the role of DNA methylation in prokaryotic restriction-modification systems and in a number of cellular processes in eukaryotes including gene regulation and differentiation is well documented.</p><p>This entry represents a methyltransferase domain found in a large variety of SAM-dependent methyltransferases including, but not limited to:<ul><li>Arsenite methyltransferase (<db_xref db="EC" dbkey="2.1.1.137"/>) which converts arsenical compounds to their methylated forms [<cite idref="PUB00028118"/>]</li><li>Biotin synthesis protein bioC, which is involved in the early stages of biotin biosyntheis [<cite idref="PUB00028119"/>]</li><li>Arginine N-methyltransferase 1, an arginine-methylating enzyme which acts on residues present in a glycine and argine-rich domain and can methylate histones [<cite idref="PUB00028120"/>]</li><li>Hexaprenyldihydroxybenzoate methyltransferase (<db_xref db="EC" dbkey="2.1.1.114"/>), a mitochodrial enzyme involved in ubiquinone biosynthesis [<cite idref="PUB00013843"/>]</li><li> A probable cobalt-precorrin-6Y C(15)-methyltransferase thought to be involved in adenosylcobalamin biosynthesis [<cite idref="PUB00015329"/>]</li><li>Sterol 24-C-methyltransferase (<db_xref db="EC" dbkey="2.1.1.41"/>), shown to participate in ergosterol biosynthesis [<cite idref="PUB00028121"/>]</li><li>3-demethylubiquinone-9 3-methyltransferase (<db_xref db="EC" dbkey="2.1.1.64"/>) involved in ubiquinone biosynthesis [<cite idref="PUB00028122"/>]</li></ul>Structural studies show that this domain forms the Rossman-like alpha-beta fold typical of SAM-dependent methyltransferases [<cite idref="PUB00028123"/>, <cite idref="PUB00028124"/>, <cite idref="PUB00014680"/>].</p>