title: S-adenosylmethionine and its products.
abstract: S-adenosylmethionine is involved in many processes, mainly methylation, polyamine synthesis and radical-based catalysis. It is synthesised through the catalysis of differently regulated enzyme forms. When it is used, the compounds formed are reutilized in different ways: in case of methylation, its end product is homocysteine, which can be remethylated to methionine, give rise to cysteine in the so-called transsulphuration pathway, or be released; in the case of polyamine synthesis, the methylthioadenosine formed is cleaved and gives rise to compounds which can be reutilized; during radical-based catalysis, 5-deoxyadenosine is formed and this, too, is cleaved and reutilized.
authors.affiliation: Dipartimento di Medicina e Oncologia Sperimentale, Sezione di Biochimica, Università di Torino, Torino, Italy. Mariaangelica.grillo@unito.it
authors.forename: M A
authors.initials: MA
authors.lastname: Grillo
authors.forename: S
authors.initials: S
authors.lastname: Colombatto
mesh_terms: D013766:5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase / Q000378:metabolism; D000818:Animals; D050940:Betaine-Homocysteine S-Methyltransferase / Q000378:metabolism; D003541:Cystathionine beta-Synthase / Q000378:metabolism; D050938:Glycine N-Methyltransferase / Q000378:metabolism; D006710:Homocysteine / Q000378:metabolism; D006801:Humans; D008099:Liver / Q000378:metabolism; D008716:Methionine Adenosyltransferase / Q000378:metabolism; D008745:Methylation; D012435:S-Adenosylhomocysteine / Q000378:metabolism; D012436:S-Adenosylmethionine / Q000096:biosynthesis / Q000378:metabolism*
chemical_list: D006710:Homocysteine; D012436:S-Adenosylmethionine; D012435:S-Adenosylhomocysteine; D013766:5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase; D050938:Glycine N-Methyltransferase; D050940:Betaine-Homocysteine S-Methyltransferase; D008716:Methionine Adenosyltransferase; D003541:Cystathionine beta-Synthase