This pathway visualizes the conversion of methionine to cysteine, after which it is further metabolized in either an oxidative or non-oxidative manner. Several of these metabolites are altered in people suffering from MoCD and SO; changes in metabolite concentrations (comparing MoCD cases to controls) are highlighted in blue (see [WP4507](https://www.wikipathways.org/index.php/Pathway:WP4507) for the pathway on MoCD). This pathway was inspired by Chapter 12 of the book of Blau (ISBN 3642403360 (978-3642403361)). bef AKA Glutathione synthetase aka a-ketoglutarate (a-KG) AKA Methionine synthase AKA 3-mercaptopyruvate sulfurtransferase AKA Glutamate-cysteine ligase aka Methionine adenosyltransferase AKA Adenosylhomocysteinase AKA sulfite ion. Cysteine dioxygenase type 1 AKA Cysteine sulfinic acid decarboxylase AKA Sulfite oxidase af8 aka Cystathionine beta-synthase AKA Aspartate aminotransferase aka Hydrogen sulfide AKA Methyltransferase AKA Betaine--homocysteine S-methyltransferase 1 Cystathionine gamma-lyase AKA Pyruvic acid AKA sulfur transferase AKA quinone oxidoreductase AKA glutamine AKA thiosulfate ion AKA Aspartate aminotransferase AKA persulfurated thiol-containing compound (RSSH) aka Hydrogen sulfide aka Cystathionine beta-synthase aka a-ketoglutarate (a-KG) AKA glutamine Cystathionine gamma-lyase AKA glutamine AKA glycine AKA sulfur dioxygenase AKA Sulfite oxidase b81 dd5 b81 eb2 af8 disease pathway PW:0000013 Pathway Ontology 15122900 PubMed Dissecting the catalytic mechanism of betaine-homocysteine S-methyltransferase by use of intrinsic tryptophan fluorescence and site-directed mutagenesis. Biochemistry 2004 Castro C Gratson AA Evans JC Jiracek J Collinsová M Ludwig ML Garrow TA 11076529 PubMed Protonation state of methyltetrahydrofolate in a binary complex with cobalamin-dependent methionine synthase. Biochemistry 2000 Smith AE Matthews RG 9783642403361 ISBN 'Physician's Guide to the Diagnosis, Treatment, and Follow-Up of Inherited Metabolic Diseases Springer-Verlag Berlin Heidelberg 2014 Nenad Blau Marinus Duran K Michael Gibson Carlo Dionisi-Vici 11731805 PubMed Domain alternation switches B(12)-dependent methionine synthase to the activation conformation. Nat Struct Biol 2002 Bandarian V Pattridge KA Lennon BW Huddler DP Matthews RG Ludwig ML cysteine and methionine metabolic pathway PW:0001078 Pathway Ontology cysteine metabolic pathway PW:0000049 Pathway Ontology 24611772 PubMed Contribution of cysteine aminotransferase and mercaptopyruvate sulfurtransferase to hydrogen sulfide production in peripheral neurons. J Neurochem 2014 Miyamoto R Otsuguro K Yamaguchi S Ito S methionine degradation pathway PW:0001302 Pathway Ontology methionine cycle/metabolic pathway PW:0000048 Pathway Ontology amino acid metabolic pathway PW:0000011 Pathway Ontology