ACAA1 is a member of the thiolase family of enzymes and is involved in lipid metabolism. This protein is localized to the peroxisome and catalyzes the conversion of acyl-CoA and acetyl-CoA to 3-oxoacyl-CoA in the fatty acid oxidation pathway. ACAA1 shows high enzymatic activity in liver, kidney, intestine and white adipose tissue in rats. Deficiency of this enzyme leads to pseudo-Zellweger syndrome.