Fet3p is a

multicopper oxidase In molecular biology, multicopper oxidases are enzymes which oxidise their substrate by accepting electrons at a mononuclear copper centre and transferring them to a trinuclear copper centre; dioxygen binds to the trinuclear centre and, follo ...

(MCO)₂ found in ''

Saccharomyces cerevisiae ''Saccharomyces cerevisiae'' () (brewer's yeast or baker's yeast) is a species of yeast (single-celled fungus microorganisms). The species has been instrumental in winemaking, baking, and brewing since ancient times. It is believed to have been o ...

'' with a structure consisting of three cupredoxin-like β-barrel domains and four copper ions located in three distinct metal sites (T1 in domain 3, T2, and the binuclear T3 at the interface between domains 1 and 3). Fet3p is a type I

membrane protein Membrane proteins are common proteins that are part of, or interact with, biological membranes. Membrane proteins fall into several broad categories depending on their location. Integral membrane proteins are a permanent part of a cell membrane ...

with an orientation that places the amino-terminal oxidase domain in the exocellular space (N_exo) and the carboxyl terminus in the cytoplasm (C_cyt). Part of the

ferroxidase Ferroxidase also known as Fe(II):oxygen oxidoreductase is an enzyme that catalyzes the oxidization of iron II to iron III: : 4 Fe2+ + 4 H+ + O2 ⇔ 4 Fe3+ + 2H2O Examples Human genes encoding proteins with ferroxidase activity include: * CP ...

reaction, Fet3p catalyzes the

oxidation Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a d ...

of Fe(II) to Fe(III) using O₂ as substrate. The Fe(III) generated by Fet3p is a

ligand In coordination chemistry, a ligand is an ion or molecule (functional group) that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's electr ...

for the iron

permease The permeases are membrane transport proteins, a class of multipass transmembrane proteins that allow the diffusion of a specific molecule in or out of the cell in the direction of a concentration gradient, a form of facilitated diffusion. The per ...

, Ftr1p.

References

{{Portal bar, Biology, border=no Oxidoreductases