Aconitase

From Proteopedia

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Aconitase (ACO) is an enzymatic domain that confers the ability to catalyse the equilibrium

citrate = aconitate + H₂O = isocitrate

This reaction is part of the citrate (TCA-, Krebs-)cycle.

In most organims, there is a cytosolic enzyme with an ACO domain (cAc), and in eukaryotes, a second copy of it was introduced with mitochondria (mAc). Plants developed even more copies in mitochondria.

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A specialty of cAc is that in mammals it has developed a as inhibitor of that carry an . Therefore, the cytosolic cAc is named IREBP for IRE-binding protein when this function is talked about. Only one of the two functions is active, depending on whether is present in the molecule: it's essential for . You can see, by , how much the enzyme structure differs between those two functions.

Weblinks

• Molecule of the Month: Aconitase and Iron Regulatory Protein 1
• Aconitase at Wikipedia