3-hydroxy-3-methylglutaryl coenzyme a reductase ( hmg coa reductase ) is a single polypeptide chain with two contiguous domains : a soluble domain ( 548 amino acids ) that catalyzes the rate-controlling step in cholesterol synthesis and a membrane-bound domain ( 339 amino acids ) that anchors the protein to the endoplasmic reticulum ( er ) .
C0063164
3-hydroxy-3-methylglutaryl coenzyme a reductase
C0020374
hmg coa reductase