Mitochondrial acetyl-CoA acetyltransferase that catalyzes both the formation and degradation of acetoacetyl-CoA (PubMed:32005728). Has no overlapping function with erg10B and seems not to be involved in ergosterol biosynthesis (PubMed:32005728). Plays an important role in growth, morphogenesis and maintaining mitochondrial function including the response to oxidative stresses (PubMed:32005728). 2 acetyl-CoA = acetoacetyl-CoA + CoA Metabolic intermediate biosynthesis; (R)-mevalonate biosynthesis; (R)-mevalonate from acetyl-CoA: step 1/3. Homotetramer. Leads to lethality. Mitochondrial erg10A is essential for A.fumigatus cell viability and might be a potential drug target to feed the antifungal drug development pipeline. Even though it is not involved in catalysis directly, the Cl(-) anion stabilizes the catalytic site via both direct and water-mediated hydrogen bonds to catalytic residues and residues adjacent. Belongs to the thiolase-like superfamily. Thiolase family.