4.1.3.16 5 9 - 4.1.3.16 6 9.5 2-keto-4-hydroxybutyrate cleavage 4.1.3.16 7 9 2-keto-4-hydroxyglutarate cleavage 4.1.3.16 6.3 - 50% of maximum activity 4.1.3.16 9.6 - 60% of maximum activity