Catalyzes the oxidation of either pyridoxine 5'-phosphate (PNP) or pyridoxamine 5'-phosphate (PMP) into pyridoxal 5'-phosphate (PLP). H2O + O2 + pyridoxamine 5'-phosphate = H2O2 + NH4(+) + pyridoxal 5'-phosphate O2 + pyridoxine 5'-phosphate = H2O2 + pyridoxal 5'-phosphate Binds 1 FMN per subunit. Cofactor metabolism; pyridoxal 5'-phosphate salvage; pyridoxal 5'-phosphate from pyridoxamine 5'-phosphate: step 1/1. Cofactor metabolism; pyridoxal 5'-phosphate salvage; pyridoxal 5'-phosphate from pyridoxine 5'-phosphate: step 1/1. Homodimer. Belongs to the pyridoxamine 5'-phosphate oxidase family.