Category: amino-acid
Aliases: Met, M, L-Methionine
Translation-initiator amino acid (every eukaryotic protein starts with Met). Converts to [[same]] (S-adenosyl-methionine) — the principal methyl donor for >100 methyltransferases including DNMT (DNA), HMT (histones), COMT (catecholamines), GNMT (creatine), and PEMT (phosphatidylcholine). Demethylated to S-adenosyl-homocysteine (SAH) → [[homocysteine]] → back to methionine ([[methionine_sam_cycle]] B12-dependent methionine synthase) or to [[cysteine]] (transsulfuration).