Now, in the next step, we basically want to isomerize. So we want to transform this CIS group into a TransGroup. So we have the cyst double bond here, but we want to form a trans double bond, as shown here. So the enzyme that catalyze this step is an isomerase. So we have malleal acetoacetate isomerase, which uses the activity of glutathione to basically form this molecule, the four funeral acetylacetate. And the final step in this reaction, in which we ultimately want to cleave this Sigma bond here by using essentially a water molecule, this is catalyzed by fumarol acetylacetase.