Threonine synthase
In enzymology, a threonine synthase (EC 4.2.3.1) is an enzyme that catalyzes the chemical reaction
- O-phospho-L-homoserine + H2O L-threonine + phosphate
| threonine synthase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 threonine synthase dimer, Arabidopsis thaliana | |||||||||
| Identifiers | |||||||||
| EC number | 4.2.3.1 | ||||||||
| CAS number | 9023-97-6 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| Gene Ontology | AmiGO / QuickGO | ||||||||
| |||||||||
Thus, the two substrates of this enzyme are O-phospho-L-homoserine and H2O, whereas its two products are L-threonine and phosphate.
This enzyme belongs to the family of lyases, specifically those carbon-oxygen lyases acting on phosphates. The systematic name of this enzyme class is O-phospho-L-homoserine phosphate-lyase (adding water L-threonine-forming). Other names in common use include threonine synthetase, and O-phospho-L-homoserine phospho-lyase (adding water). This enzyme participates in glycine, serine and threonine metabolism and vitamin B6 metabolism. It employs one cofactor, pyridoxal phosphate.
Structural studies
As of late 2007, 7 structures have been solved for this class of enzymes, with PDB accession codes 1UIM, 1UIN, 1V7C, 1VB3, 2C2B, 2C2G, and 2D1F.
References
- FLAVIN M, SLAUGHTER C (1960). "Purification and properties of threonine synthetase of Neurospora". J. Biol. Chem. 235: 1103–8. PMID 13823379.