Hydroxymethylglutaryl-CoA lyase（HMGCL) is a mitochondrial matrix protein which is a member of the HMG-CoA lyase family. HMGCL is a homodimer and participates in leucine catabolism and ketogenesis， the hepatic synthesis of ketone bodies which， during fasting， provides a major source of energy for the heart， brain and kidney. More precisely， HMGCL catalyzes the final step of these processes， the cleavage of 3-hydroxy-3-methylglutaryl-CoA to acetoacetic acid and acetyl-CoA.
