Has no detectable activity towards cis-acontiate or cis-homoaconitate. The fermenting yeast S.cerevisiae has 2 aconitases, ACO1 essential for the citric acid cycle, and ACO2 specifically and exclusively contributing to lysine biosynthesis. In contrast, in respiring filamentous fungi the ACO2 homologs (acoB) seem enzymatically inactive and the ACO1 homolog (acoA) is solely responsible for these functions. Belongs to the aconitase/IPM isomerase family.