Homocysteine and cysteine interconversion (Saccharomyces cerevisiae)

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The first five steps of arginine biosynthesis in S. cerevisiae take place in the mitochondrion (CITS: [11553611])(CITS: [Hinnebusch]). This part of the pathway is known as the acetylated derivatives cycle because the acetyl group that is added to L-glutamate in the first step of the pathway is recycled via N-acetylglutamate generated in the fifth step. The enzymes that catalyze the second and third steps are encoded by a single gene (ARG5,6) that is translated into a pre-protein which is imported into mitochondria and cleaved there to yield two enzymes, N-acetylglutamate kinase and N-acetylglutamyl-phosphate reductase (CITS: [1649049]). These enzymes form a complex with each other and with N-acetylglutamate synthase, the first enzyme in the pathway, which may have implications for regulation of their activity (CITS: [11553611]). The mitochondrial steps of the arginine biosynthesis pathway result in the formation of ornithine, which is exported to the cytoplasm by the transporter Ort1p (CITS: [8798783]). In the cytoplasm, L-ornithine is converted to L-arginine in three reactions mediated by ornithine carbamoyltransferase, arginosuccinate synthase, and argininosuccinate lyase. Transcription of genes of the arginine biosynthetic pathway, as well as of other amino acid biosynthetic pathways, is activated by the transcription factor Gcn4p under conditions of amino acid starvation (CITS: [11390663])(CITS: [Hinnebusch]). Transcription of ARG1, ARG3, ARG5,6, and ARG8 is also repressed in the presence of arginine by the ArgR/Mcm1p complex, which consists of Arg80p, Arg81p, Arg82p, and Mcm1p (CITS: [14563547]). The transcriptional activator Gcn4p interacts with subunits of the ArgR/Mcm1p repressor, allowing for fine-tuning of transcriptional control in response to arginine availability (CITS: [15289616]). SOURCE: SGD pathways, http://pathway.yeastgenome.org/server.html


Based on http://pathway.yeastgenome.org/biocyc/

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  1. Thomas D, Surdin-Kerjan Y; ''Metabolism of sulfur amino acids in Saccharomyces cerevisiae.''; Microbiol Mol Biol Rev, 1997 PubMed Europe PMC Scholia


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117301view11:17, 20 May 2021EweitzModified title
92820view19:35, 8 July 2017AlexanderPicoRemoved old genmapp tags and unused attributes
92819view19:35, 8 July 2017AlexanderPicoReverted to version '03:47, 11 July 2013' by AlexanderPico
92791view15:18, 6 July 2017DeSlQuick edit to datanode annotation or property
69755view10:47, 11 July 2013EgonwMarked a few DataNodes with CAS registry numbers as metabolites.
69642view20:37, 8 July 2013MaintBotUpdated to 2013 gpml schema
67340view10:39, 26 June 2013Christine ChichesterOntology Term : 'cysteine metabolic pathway' added !
41880view04:52, 2 March 2011MaintBotRemoved redundant pathway information and comments
36653view22:39, 9 April 2010MaintBotDescription and bibliography added from SGD
20951view11:30, 14 November 2008MaintBot[[Pathway:Saccharomyces cerevisiae:Homocysteine and Cysteine Interconversion]] moved to [[Pathway:WP128]]: Moved to stable identifier
12750view08:01, 17 May 2008MaintBotautomated metabolite conversion
8786view14:09, 7 January 2008MaintBotAdded to category $category
8784view14:09, 7 January 2008M.BraymerUploaded new pathway

External references


View all...
NameTypeDatabase referenceComment
CYS3GeneProductS000000010 (SGD)
CYS4GeneProductS000003387 (SGD)
L-cysteineMetabolite52-90-4 (CAS)
L-serineMetabolite56-45-1 (CAS)
STR2GeneProductS000003891 (SGD)
STR3GeneProductS000003152 (SGD)
acetateMetabolite64-19-7 (CAS)
cystathionineMetabolite56-88-2 (CAS)
homocysteineMetabolite6027-13-0 (CAS)

Annotated Interactions

No annotated interactions
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