2.5.1.6 ATP + L-methionine + H2O - 2.5.1.6 ATP + L-methionine + H2O the product S-adenosylmethionine is important as a direct metabolic donor of methyl and alpha-amino-n-butyryl groups 2.5.1.6 ATP + L-methionine + H2O used as aminopropyl group donor in synthesis of polyamines and is also the methyl group donor for most cellular methyltransferase reactions 2.5.1.6 ATP + L-methionine + H2O methyl donor in transmethylation reactions and as propylamine donor for polyamine biosynthesis 2.5.1.6 ATP + L-methionine + H2O two reaction steps: S-adenosylmethionine synthesis and tripolyphosphate hydrolysis. Tripolyphosphate hydrolysis is the rate determining reaction 2.5.1.6 ATP + L-methionine + H2O MAT activity controls cellular glutathione levels, polyamine synthesis and folate cycling 2.5.1.6 ATP + L-methionine + H2O a post-translational mechanism is involved in MAT regulation, the enzyme is down-regulated in pathological processes such as liver cirrhosis, overview 2.5.1.6 ATP + L-methionine + H2O an essential enzyme that catalyzes the formation of the principal methyl donor S-adenosylmethionine, S-adenosyl-L-methionine is also a key metabolite that regulates hepatocyte growth, death and differentiation, molecular mechanism, overview, abnormalities in MAT and decreased S-adenosyl-L-methionine levels occur in humans with alcoholic liver disease, chronic hepatic S-adenosyl-L-methionine deficiency can result in the spontaneous development of steatohepatitis and hepatocellular carcinoma, overview, hepatic S-adenosyl-L-methionine biosynthesis and methionine metabolism, overview 2.5.1.6 ATP + L-methionine + H2O aspartate family biosynthesis pathway and methionine metabolism, regulation, S-adenosyl-L-methionine activates threonine synthase expression and negatively regulates the transcript level of the cystathionine gamma-synthase, overview 2.5.1.6 ATP + L-methionine + H2O aspartate family biosynthesis pathway and methionine metabolism,regulation, S-adenosyl-L.methionine activates threonine synthase expression and negatively regulates the transcript level of the cystathionine gamma-synthase, overview