Nomenclature	acetyl‐CoA acetyltransferase 1	acetyl‐CoA acetyltransferase 2	hydroxymethylglutaryl‐CoA synthase 1	hydroxymethylglutaryl‐CoA synthase 2
HGNC, UniProt	ACAT1, P24752	ACAT2, Q9BWD1	HMGCS1, Q01581	HMGCS2, P54868
EC number	2.3.1.9: 2acetyl CoA = acetoacetyl CoA + coenzyme A	2.3.1.9: 2acetyl CoA = acetoacetyl CoA + coenzyme A	2.3.3.10: acetyl CoA + H2O + acetoacetyl CoA ‐>(S)‐3‐hydroxy‐3‐methylglutaryl‐CoA + coenzyme A	2.3.3.10: acetyl CoA + H2O + acetoacetyl CoA ‐>(S)‐3‐hydroxy‐3‐methylglutaryl‐CoA + coenzyme A
Comments	–	–	HMGCoA synthase is found in cytosolic (HMGCoA synthase 1) and mitochondrial (HMGCoA synthase 2) versions; the former associated with (R)‐mevalonate synthesis and the latter with ketogenesis.	HMGCoA synthase is found in cytosolic (HMGCoA synthase 1) and mitochondrial (HMGCoA synthase 2) versions; the former associated with (R)‐mevalonate synthesis and the latter with ketogenesis.