3-Ketoacyl-CoA thiolase, mitochondrial also known as acetyl-Coenzyme A acyltransferase 2 is an enzyme that in humans is encoded by the ACAA2 gene. Acetyl-Coenzyme A acyltransferase 2 is an acetyl-CoA C-acyltransferase enzyme. The encoded protein catalyzes the last step of the mitochondrial fatty acid beta-oxidation spiral. Unlike most mitochondrial matrix proteins, it contains a non-cleavable amino-terminal targeting signal.