coproporphyrinogen oxidase activity

Definition

Target type: molecularfunction

Catalysis of the reaction: coproporphyrinogen III + 2 H+ + O2 = 2 CO2 + 2 H2O + protoporphyrinogen IX. [EC:1.3.3.3, RHEA:18257]

Coproporphyrinogen oxidase (also known as protoporphyrinogen oxidase) is a key enzyme in the heme biosynthesis pathway. Its primary function is to catalyze the oxidative decarboxylation of coproporphyrinogen III to protoporphyrinogen IX. This reaction involves the removal of the propionate side chains at positions 6 and 7 of coproporphyrinogen III, replacing them with vinyl groups. The enzyme utilizes molecular oxygen (O2) as an electron acceptor, and this process requires the presence of a tightly bound flavin adenine dinucleotide (FAD) cofactor. The reaction occurs in two steps. First, coproporphyrinogen III binds to the enzyme, and the FAD cofactor is reduced by the substrate. Then, molecular oxygen binds to the reduced FAD, forming a reactive oxygen species that oxidizes the substrate, resulting in the decarboxylation of the propionate side chains. The resulting protoporphyrinogen IX then undergoes further modifications to become heme, a crucial component of hemoglobin, myoglobin, and other hemoproteins involved in oxygen transport and electron transfer. The activity of coproporphyrinogen oxidase is essential for heme biosynthesis, and deficiencies in this enzyme can lead to various porphyrias, genetic disorders characterized by the accumulation of porphyrin precursors in erythrocytes, body fluids, and tissues.'
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Proteins (1)

Compounds (1)