aconitase

noun

acon·​i·​tase ə-ˈkän-ə-ˌtās 

: an enzyme occurring in many animal and plant tissues that accelerates the conversion of citric acid first into aconitic acid and then into isocitric acid during the Krebs cycle

Note: Aconitase also functions in regulating levels of iron in the cell by inhibiting the formation of ferritin. It has an active site of iron and sulfur.

… recent studies have shown that aconitase is an early target of free radical damage in stressed cells because of the presence of an iron-sulfur cluster in the enzyme.

—Kyra J. Cowan, in Functional Metabolism: Regulation and Adaptation