Hydroxymethylglutaryl-CoA Synthase

**Definition:** An enzyme that catalyzes the synthesis of hydroxymethylglutaryl-CoA from acetyl-CoA and acetoacetyl-CoA. This is a key enzyme in steroid biosynthesis. This enzyme was formerly listed as EC 4.1.3.5.

**Tree numbers:** - D08.811.913.050.612

**Synonyms:** - HMG CoA Synthase - HMG-CoA synthase - 3-hydroxy-3-methylglutaryl-coenzyme A synthase