Enables L-isoleucine-2-oxoglutarate transaminase activity; L-leucine-2-oxoglutarate transaminase activity; and L-valine-2-oxoglutarate transaminase activity. Involved in L-leucine catabolic process; isoleucine catabolic process; and valine catabolic process. Predicted to be located in mitochondrial matrix. Predicted to be active in mitochondrion. Is expressed in adult head and spermatozoon. Used to study amino acid metabolic disorder. Human ortholog(s) of this gene implicated in hypervalinemia and hyperleucine-isoleucinemia. Orthologous to several human genes including BCAT2 (branched chain amino acid transaminase 2).