1-aminocyclopropane-1-carboxylate + ascorbate + O₂ $rightleftharpoons$ ethylene + cyanide + dehydroascorbate + CO₂ + 2 H₂O

The 3 substrates of this enzyme are 1-aminocyclopropane-1-carboxylate, ascorbate, and O₂, whereas its 5 products are ethylene, cyanide, dehydroascorbate, CO₂, and H₂O.

This enzyme belongs to the family of oxidoreductases, specifically those acting on paired donors, with O2 as oxidant and incorporation or reduction of oxygen. The oxygen incorporated need not be derived from O2 with reduced ascorbate as one donor, and incorporation of one ato of oxygen into the other donor. The systematic name of this enzyme class is 1-aminocyclopropane-1-carboxylate oxygenase (ethylene-forming). Other names in common use include ACC oxidase, and ethylene-forming enzyme.

Structural studies

As of late 2007, two structures have been solved for this class of enzymes, with PDB accession codes and .

References

• Zhang Z, Schofield CJ, Baldwin JE, Thomas P, John P "Expression, purification and characterization of 1-aminocyclopropane-1-carboxylate oxidase from tomato in Escherichia coli". Biochem. J. 307 77–85.
• Zhang Z, Barlow JN, Baldwin JE, Schofield CJ "Metal-catalyzed oxidation and mutagenesis studies on the iron(II) binding site of 1-aminocyclopropane-1-carboxylate oxidase". Biochemistry. 36 15999–6007.
• Pirrung MC "Ethylene biosynthesis from 1-aminocyclopropanecarboxylic acid". Acc. Chem. Res. 32 711–718.
• Charng YY, Chou SJ, Jiaang WT, Chen ST, Yang SF "The catalytic mechanism of 1-aminocyclopropane-1-carboxylic acid oxidase". Arch. Biochem. Biophys. 385 179–85.
• Thrower JS, Blalock R 3rd Klinman JP "Steady-state kinetics of substrate binding and iron release in tomato ACC oxidase". Biochemistry. 40 9717–24.

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