Enables acetyl-CoA C-acyltransferase activity. Involved in fatty acid beta-oxidation. Located in mitochondrion. Part of mitochondrial fatty acid beta-oxidation multienzyme complex. Human ortholog(s) of this gene implicated in mitochondrial metabolism disease and mitochondrial trifunctional protein deficiency. Orthologous to human HADHB (hydroxyacyl-CoA dehydrogenase trifunctional multienzyme complex subunit beta). [provided by Alliance of Genome Resources, Apr 2022]