Iron transport multicopper ferroxidase required for Fe(2+) ion high affinity uptake. Required to oxidize Fe(2+) to Fe(3+), which is then transported into the cell via the ferric iron permease FTR1. Essential component of copper-dependent iron transport. 4 Fe(2+) + 4 H(+) + O2 = 4 Fe(3+) + 2 H2O Binds 4 Cu cations per monomer. By iron deprivation. Repressed by iron excess. Present with 1050 molecules/cell in log phase SD medium. Belongs to the multicopper oxidase family.