In enzymology, a homoserine kinase (EC 18.104.22.168) is an enzyme that catalyzes the chemical reaction
- ATP + L-homoserine ADP + O-phospho-L-homoserine
Thus, the two substrates of this enzyme are ATP and L-homoserine, whereas its two products are ADP and O-phospho-L-homoserine.
This enzyme belongs to the family of transferases, specifically those transferring phosphorus-containing groups (phosphotransferases) with an alcohol group as acceptor. The systematic name of this enzyme class is ATP:L-homoserine O-phosphotransferase. Other names in common use include homoserine kinase (phosphorylating), and HSK. This enzyme participates in glycine, serine and threonine metabolism.
As of late 2007, 6 structures have been solved for this class of enzymes, with PDB accession codes 1FWK, 1FWL, 1H72, 1H73, 1H74, and 2PPQ.
- FLAVIN M, SLAUGHTER C (1960). "Purification and properties of threonine synthetase of Neurospora". J. Biol. Chem. 235: 1103–8. PMID 13823379.
- Watanabe Y, Konishi S, Shimura K (1957). "Biosynthesis of threonine from homoserine. VI. Homoserine kinase". J. Biochem. 44: 299–307.