Cysteine and methionine catabolism (WP4504)

Homo sapiens

This pathway visualises the conversion of methionine to cysteine, after which it is further metabolised 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 [] for the pathway on MoCD). This pathway was inspired by Chapter 12 of the book of Blau (ISBN 3642403360 (978-3642403361)).
last edited


Denise Slenter , Egon Willighagen , Irene Hemel , Daniel Domingo-Fdez , Friederike Ehrhart , and Finterly Hu

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Homo sapiens


Inborn Errors of Metabolism (IEM) Pathways Rare Diseases


Pathway Ontology: methionine degradation pathway cysteine and methionine metabolic pathway cysteine metabolic pathway methionine cycle/metabolic pathway disease pathway


Label Type Compact Identifier Comment
Methionine Metabolite chebi:57844
Tetra-hydrofolate Metabolite chebi:57453
Cystathionine Metabolite chebi:58161
-CH3 Metabolite chebi:32875
ATP Metabolite chebi:30616
Sulfate Metabolite chebi:16189
KG Metabolite chebi:16810 aka a-ketoglutarate (a-KG)
Taurine Metabolite chebi:15891
3-Mercaptopyruvic acid Metabolite chebi:57678
Sulfite Metabolite chebi:17359
S-Adenosylmethionine Metabolite chebi:59789
Cysteine Metabolite chebi:35235
CO2 Metabolite chebi:16526
SO3 2- Metabolite chebi:17359 AKA sulfite ion.
Glutathione Metabolite chebi:57925
S-Adenosylhomocysteine Metabolite chebi:57856
Dimethylglycine Metabolite chebi:58251
5-Methyltetrahydrofolate Metabolite chebi:18608
Hypotaurine Metabolite chebi:57853
gamma-Glutamylcysteine Metabolite chebi:58173
Cystine Metabolite chebi:17376
H2S Metabolite chebi:29919 aka Hydrogen sulfide
H2O Metabolite chebi:15377
S-sulfocysteine Metabolite chebi:27891
Betaine Metabolite chebi:17750
alpha-KB Metabolite chebi:16763
Pyr Metabolite chebi:15361 AKA Pyruvic acid
Cysteine sulfinic acid Metabolite chebi:61085
serine Metabolite chebi:33384
Glu Metabolite chebi:29985 AKA glutamine
O2 Metabolite chebi:15379
thiosulfate(2−) Metabolite chebi:16094 AKA thiosulfate ion
B-Sulfinyl pyruvate Metabolite hmdb:HMDB0002332
Homocysteine Metabolite chebi:58199
RSSH Metabolite chebi:30605 AKA persulfurated thiol-containing compound (RSSH)
H2S Metabolite chebi:16136 aka Hydrogen sulfide
Adenosine Metabolite chebi:16335
NH4+ Metabolite chebi:28938
KG Metabolite chebi:16810 aka a-ketoglutarate (a-KG)
Glu Metabolite chebi:28300 AKA glutamine
Glu Metabolite chebi:29985 AKA glutamine
Gly Metabolite chebi:57305 AKA glycine
MAT GeneProduct uniprot:Q00266 aka Methionine adenosyltransferase
SO GeneProduct uniprot:P51687 AKA Sulfite oxidase
MT GeneProduct brenda:2.1.1 AKA Methyltransferase
SO GeneProduct brenda: AKA Sulfite oxidase
GS Protein uniprot:P48637 AKA Glutathione synthetase
MS Protein uniprot:Q99707 AKA Methionine synthase
MPST Protein uniprot:P25325 AKA 3-mercaptopyruvate sulfurtransferase
GCS Protein uniprot:Q14TF0 AKA Glutamate-cysteine ligase
SAAH Protein uniprot:P23526 AKA Adenosylhomocysteinase
CDO Protein uniprot:Q16878 Cysteine dioxygenase type 1
CSD Protein uniprot:Q9Y600 AKA Cysteine sulfinic acid decarboxylase
CSE Protein uniprot:P35520 aka Cystathionine beta-synthase
AAT Protein uniprot:A0A140VK69 AKA Aspartate aminotransferase
BHMT Protein uniprot:Q93088 AKA Betaine--homocysteine S-methyltransferase 1
CSE Protein uniprot:P32929 Cystathionine gamma-lyase
SQR Protein uniprot:Q9Y6N5 AKA quinone oxidoreductase
AAT Protein uniprot:P17174 AKA Aspartate aminotransferase
CSE Protein uniprot:P35520 aka Cystathionine beta-synthase
CSE Protein uniprot:P32929 Cystathionine gamma-lyase
SQR Protein uniprot:Q9Y6N5
SDO Protein uniprot:O95571 AKA sulfur dioxygenase


  1. Blau N, Duran M, Gibson KM, Dionisi-Vici C. Physician’s Guide to the Diagnosis, Treatment, and Follow-Up of Inherited Metabolic Diseases [Internet]. Springer; 2014. 867 p. Available from: OpenLibrary Worldcat
  2. Smith AE, Matthews RG. Protonation state of methyltetrahydrofolate in a binary complex with cobalamin-dependent methionine synthase. Biochemistry. 2000 Nov 14;39(45):13880–90. PubMed Europe PMC Scholia
  3. Bandarian V, Pattridge KA, Lennon BW, Huddler DP, Matthews RG, Ludwig ML. Domain alternation switches B(12)-dependent methionine synthase to the activation conformation. Nat Struct Biol. 2002 Jan;9(1):53–6. PubMed Europe PMC Scholia
  4. Castro C, Gratson AA, Evans JC, Jiracek J, Collinsová M, Ludwig ML, et al. Dissecting the catalytic mechanism of betaine-homocysteine S-methyltransferase by use of intrinsic tryptophan fluorescence and site-directed mutagenesis. Biochemistry. 2004 May 11;43(18):5341–51. PubMed Europe PMC Scholia
  5. Miyamoto R, Otsuguro K-I, Yamaguchi S, Ito S. Contribution of cysteine aminotransferase and mercaptopyruvate sulfurtransferase to hydrogen sulfide production in peripheral neurons. J Neurochem. 2014 Jul;130(1):29–40. PubMed Europe PMC Scholia