Aconitate hydratase (AH), also known as aconitase, is an enzyme in the tricarboxylic acid cycle (TCA cycle) responsible for catalyzing the conversion of citrate to isocitrate. It consists of multiple functional domains, including a [4Fe-4S] cluster binding domain, and is primarily located in the mitochondria and cytoplasm. AH plays a crucial role in regulating energy metabolism and providing substrates for the electron transport chain, such as NADH. Its expression is tissue-specific, and mutations or dysregulation in its gene are associated with various diseases, including neurodegenerative diseases, tumors, and metabolic disorders. The activity of AH is regulated by oxidative stress and levels of iron ions, affecting the physiological state and adaptability of cells.