MetaCyc Reaction:

Superclasses: Reactions Classified By Conversion TypeSimple ReactionsChemical Reactions
Reactions Classified By SubstrateSmall-Molecule Reactions

EC Number:

Enzymes and Genes:

Arabidopsis thaliana col: phosphoserine aminotransferaseInferred from experiment: PSAT
Escherichia coli K-12 substr. MG1655: 3-phosphoserine aminotransferaseInferred from experiment: serC
Homo sapiens: phosphoserine aminotransferaseInferred from experiment: PSAT1
Methanocaldococcus jannaschii: phosphoserine aminotransferaseInferred from experiment: serC
Methanosarcina acetivorans: phosphoserine aminotransferaseInferred from experiment: serC
Rattus norvegicus: phosphoserine aminotransferase 1Inferred from experiment: Psat1

In Pathway: L-serine biosynthesis

The direction shown, i.e. which substrates are on the left and right sides, is in accordance with the Enzyme Commission system.

Mass balance status: Balanced.

Enzyme Commission Primary Name: phosphoserine transaminase

Enzyme Commission Synonyms: PSAT, phosphoserine aminotransferase, 3-phosphoserine aminotransferase, hydroxypyruvic phosphate-glutamic transaminase, L-phosphoserine aminotransferase, phosphohydroxypyruvate transaminase, phosphohydroxypyruvic-glutamic transaminase, 3-O-phospho-L-serine:2-oxoglutarate aminotransferase, SerC, PdxC, 3PHP transaminase

Standard Gibbs Free Energy (ΔrG in kcal/mol): 0.07583618Inferred by computational analysis [Latendresse13]

Enzyme Commission Summary:
A pyridoxal-phosphate protein. This enzyme catalyses the second step in the phosphorylated pathway of serine biosynthesis in Escherichia coli [Pizer63, Zhao96]. It also catalyses the third step in the biosynthesis of the coenzyme pyridoxal 5-phosphate in Escherichia coli (using Reaction 2 above) [Zhao96]. In Escherichia coli, pyridoxal 5-phosphate is synthesized de novo by a pathway that involves EC (erythrose-4-phosphate dehydrogenase), EC (4-phosphoerythronate dehydrogenase), EC (phosphoserine transaminase), EC (4-hydroxythreonine-4-phosphate dehydrogenase), EC (pyridoxine 5-phosphate synthase) and EC (with pyridoxine 5-phosphate as substrate). Pyridoxal phosphate is the cofactor for both activities and therefore seems to be involved in its own biosynthesis [Drewke96]. Non-phosphorylated forms of serine and threonine are not substrates [Drewke96].

Citations: [Hirsch67, Zhao96a]

Gene-Reaction Schematic

Gene-Reaction Schematic

Unification Links: KEGG:R04173, Rhea:14329

Relationship Links: BRENDA:EC:, ENZYME:EC:, IUBMB-ExplorEnz:EC:, UniProt:RELATED-TO:O34370, UniProt:RELATED-TO:P10658, UniProt:RELATED-TO:P19689, UniProt:RELATED-TO:P23721, UniProt:RELATED-TO:P33330, UniProt:RELATED-TO:P44336, UniProt:RELATED-TO:P62676, UniProt:RELATED-TO:Q9CHW5, UniProt:RELATED-TO:Q9PIH3


Drewke96: Drewke C, Klein M, Clade D, Arenz A, Muller R, Leistner E (1996). "4-O-phosphoryl-L-threonine, a substrate of the pdxC(serC) gene product involved in vitamin B6 biosynthesis." FEBS Lett 1996;390(2);179-82. PMID: 8706854

Hirsch67: Hirsch H, Greenberg DM (1967). "Studies on phosphoserine aminotransferase of sheep brain." J Biol Chem 242(9);2283-7. PMID: 6022873

Latendresse13: Latendresse M. (2013). "Computing Gibbs Free Energy of Compounds and Reactions in MetaCyc."

Pizer63: Pizer LI (1963). "The pathway and control of serine biosynthesis in Escherichia coli." J Biol Chem 1963;238:3934-3944. PMID: 14086727

Zhao96: Zhao G, Winkler ME (1996). "A novel alpha-ketoglutarate reductase activity of the serA-encoded 3-phosphoglycerate dehydrogenase of Escherichia coli K-12 and its possible implications for human 2-hydroxyglutaric aciduria." J Bacteriol 1996;178(1);232-9. PMID: 8550422

Zhao96a: Zhao G, Winkler ME (1996). "4-Phospho-hydroxy-L-threonine is an obligatory intermediate in pyridoxal 5'-phosphate coenzyme biosynthesis in Escherichia coli K-12." FEMS Microbiol Lett 1996;135(2-3);275-80. PMID: 8595869

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Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
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