Cystathionine gamma-synthase

In enzymology, a cystathionine gamma-synthase is an enzyme that catalyzes the chemical reaction


 * O4-succinyl-L-homoserine + L-cysteine $$\rightleftharpoons$$ L-cystathionine + succinate

Thus, the two substrates of this enzyme are O4-succinyl-L-homoserine and L-cysteine, whereas its two products are L-cystathionine and succinate.

This enzyme belongs to the family of transferases, specifically those transferring aryl or alkyl groups other than methyl groups. The systematic name of this enzyme class is O4-succinyl-L-homoserine:L-cysteine S-(3-amino-3-carboxypropyl)transferase. Other names in common use include O-succinyl-L-homoserine succinate-lyase (adding cysteine), O-succinylhomoserine (thiol)-lyase, homoserine O-transsuccinylase, O-succinylhomoserine synthase, O-succinylhomoserine synthetase, cystathionine synthase, cystathionine synthetase, homoserine transsuccinylase, 4-O-succinyl-L-homoserine:L-cysteine, and S-(3-amino-3-carboxypropyl)transferase. This enzyme participates in 4 metabolic pathways: methionine metabolism, cysteine metabolism, selenoamino acid metabolism, and sulfur metabolism. It employs one cofactor, pyridoxal phosphate.