产品介绍： SAM (S-adenosylmethionin synthetase) is an enzyme which catalyzes the formation of S-adenosylmethionine from methionine and ATP. The overall synthetic reaction is composed of two sequential steps. It is a donor of methyl groups in methylation reactions, and is involved in a number of processes such as: response to cadmium ions and salt stress, as well as, ethylene and lignin biosynthesis.