Phosphoserine transaminase
| Phosphoserine transaminase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC no. | 2.6.1.52 | ||||||||
| CAS no. | 9030-90-4 | ||||||||
| Databases | |||||||||
| BRENDA | enzyme data | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | enzyme entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| Rhea | reactions | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| |||||||||
Phosphoserine transaminase (EC 2.6.1.52, 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) is an enzyme with systematic name O-phospho-L-serine:2-oxoglutarate aminotransferase.[1] This enzyme catalyses two reversible chemical reactions. In the first, phosphoserine is converted to phosphohydroxypyruvic acid by transfer of an amino group to α-ketoglutaric acid, giving L-glutamic acid:
This reaction normally proceeds in the direction of formation of phosphoserine, and is part of the pathway to the amino acid, serine, as found in Escherichia coli and sheep.[2][3][4] As with many aminotransferases, the enzyme uses pyridoxal phosphate as a cofactor.[5][6]
Alternatively, 4-(phosphonooxy)-L-threonine is converted to (R)-3-hydroxy-2-oxo-4-phosphonooxybutanoic acid with the same α-ketoglutaric acid / L-glutamic acid exchange:
-L-threonine.svg.png)
acid
-3-hydroxy-2-oxo-4-phosphonooxybutanoic_acid.svg.png)
acid
This reaction, when used to give 4-(phosphonooxy)-L-threonine, is part of the biosynthesis of vitamin B6, (pyridoxal 5'-phosphate), and thus the enzyme in E. coli is involved in making its own cofactor.[7][8]
See also
References
- ↑ Enzyme 2.6.1.52 at KEGG Pathway Database.
- ↑ Pizer LI (December 1963). "The pathway and control of serine biosynthesis in Escherichia coli". The Journal of Biological Chemistry. 238 (12): 3934–44. doi:10.1016/S0021-9258(18)51809-3. PMID 14086727.
- ↑ Hirsch H, Greenberg DM (May 1967). "Studies on phosphoserine aminotransferase of sheep brain". The Journal of Biological Chemistry. 242 (9): 2283–7. doi:10.1016/S0021-9258(18)96047-3. PMID 6022873.
- ↑ Zhao G, Winkler ME (January 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". Journal of Bacteriology. 178 (1): 232–9. doi:10.1128/jb.178.1.232-239.1996. PMC 177644. PMID 8550422.
- ↑ Baek, Joo Youn; Jun, D. Youn; Taub, Dennis; Kim, Young Ho (2003). "Characterization of human phosphoserine aminotransferase involved in the phosphorylated pathway of l-serine biosynthesis". Biochemical Journal. 373 (Pt 1): 191–200. doi:10.1042/BJ20030144. PMC 1223456. PMID 12633500.
- ↑ HelgadóTtir, Sunna; Rosas-Sandoval, Guillermina; SöLl, Dieter; Graham, David E. (2007). "Biosynthesis of Phosphoserine in the Methanococcales". Journal of Bacteriology. 189 (2): 575–582. doi:10.1128/JB.01269-06. PMC 1797378. PMID 17071763.
- ↑ Drewke C, Klein M, Clade D, Arenz A, Müller R, Leistner E (July 1996). "4-O-phosphoryl-L-threonine, a substrate of the pdxC(serC) gene product involved in vitamin B6 biosynthesis". FEBS Letters. 390 (2): 179–82. Bibcode:1996FEBSL.390..179D. doi:10.1016/0014-5793(96)00652-7. PMID 8706854.
- ↑ Zhao G, Winkler ME (January 1996). "4-Phospho-hydroxy-L-threonine is an obligatory intermediate in pyridoxal 5'-phosphate coenzyme biosynthesis in Escherichia coli K-12". FEMS Microbiology Letters. 135 (2–3): 275–80. doi:10.1111/j.1574-6968.1996.tb08001.x. PMID 8595869.
External links
- Phosphoserine+transaminase at the U.S. National Library of Medicine Medical Subject Headings (MeSH)