Threonine synthase

In enzymology, a threonine synthase (EC4.2.3.1) is an enzyme that catalyzes the chemical reaction

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.