Cysteine Synthase

**Definition:** An enzyme that catalyzes the biosynthesis of cysteine in microorganisms and plants from O-acetyl-L-serine and hydrogen sulfide. This enzyme was formerly listed as EC 4.2.99.8.

**Tree numbers:** - D08.811.913.225.224

**Synonyms:** - O-Acetylserine (Thiol)-Lyase - O-Acetylserine Sulfhydrylase