Rate limiting step in cholesterol synthesis is catalysed by which of the following enzyme?

Conversion of HMG CoA to mevalonate by HMG CoA reductase is the rate limiting step in the synthesis of cholesterol. Cholesterol is an allosteric inhibitor of HMG CoA reductase Statin drugs acts as competitive inhibitors with mevalonate for binding to HMG CoA reductase. Insulin ors the active form of HMG CoA reductase and increases cholesterol synthesis. Glucagon ours the inactive form and decreases cholesterol synthesis. Ref: Biochemistry By John W. Pelley, page 89.