part of ubiquinone biosynthetic process O-methyltransferase activity S-adenosylmethionine-dependent methyltransferase activity 3-demethylubiquinol 3-O-methyltransferase activity https://github.com/geneontology/go-ontology/issues/25680 https://github.com/geneontology/go-ontology/issues/29420 https://github.com/geneontology/go-ontology/issues/30193 EC:2.1.1.64 RHEA:44412 Note that the polyprenyl sidechain substrate for this reaction has a different number of prenyl units in different organisms (for example, ubiquinone-6 in Saccharomyces, ubiquinone- 9 in rat and ubiquinone-10 in human), and thus the natural substrate for the enzymes from different organisms has a different number of prenyl units. However, the enzyme usually shows a low degree of specificity regarding the number of prenyl units. molecular_function GO:0061542 3-demethylubiquinol-n 3-O-methyltransferase activity 2-octaprenyl-3-methyl-5-hydroxy-6-methoxy-1,4-benzoquinone methyltransferase dph OMHMB-methyltransferase 2013-06-25T08:01:46Z 5-demethylubiquinone-10 methyltransferase RHEA:44400 RHEA:44404 RHEA:17049 S-adenosyl-L-methionine:2-octaprenyl-3-methyl-5-hydroxy-6-methoxy-1,4-benzoquinone-O-methyltransferase Catalysis of the reaction: a 3-demethylubiquinol + S-adenosyl-L-methionine = a ubiquinol + S-adenosyl-L-homocysteine + H+. Reactome:R-HSA-2162186 RHEA:44380 5-demethylubiquinone-9 methyltransferase RHEA:28679