MitoSciences: Acetyl-CoA acetyltransferase (ACAT1)

UniProt Number:	P24752
Alternate Names:	Acetoacetyl-CoA thiolase, T2, THIL, ACAT, MAT
Structure and Function:	Acetyl-Coenzyme A acetyltransferase (ACAT1), also called 2-methylacetoacetyl,AiCoA thiolase or beta-ketothiolase is a mitochondrial enzyme involved in both amino acid degradation and in fatty acid oxidation. It catalyzes the last step in breaking down isoleucine by converting 2-methyl-acetoacetyl-CoA into propionyl-CoA and acetyl CoA. During ketolysis, it converts a acetoacetyl-CoA to two molecules of acetyl CoA. Note that there is a cytosolic form of the enzyme (ACAT2) which can link two molecules of acetyl,AiCoA to acetoacetyl-CoA as an early step in ketogenesis and in fatty acid biogenesis.
Disease Associations:	Defects in ACAT1 are a cause of 3-ketothiolase deficiency (3KTD) [MIM:203750], also known as alpha-methylacetoaceticaciduria. 3KTD is an inborn error of isoleucine catabolism characterized by intermittent ketoacidotic attacks associated with unconsciousness.