ID 2.1.1.373 DE 2-hydroxy-4-(methylsulfanyl)butanoate S-methyltransferase. AN methylthiohydroxybutyrate methyltransferase. AN MTHB methyltransferase. CA (2R)-2-hydroxy-4-(methylsulfanyl)butanoate + S-adenosyl-L-methionine = CA (2R)-4-(dimethylsulfaniumyl)-2-hydroxybutanoate + S-adenosyl-L- CA homocysteine. CC -!- The enzyme, characterized from the marine bacterium Labrenzia CC aggregata, participates in the biosynthesis of CC dimethylsulfoniopropanoate (DMSP). CC -!- A eukaryotic enzyme that shares little sequence similarity with the CC bacterial enzyme was identified in many marine phytoplankton species. //