Catalyzes the oxidation of methanol to formaldehyde and hydrogen peroxide, the first step in the methanol utilization pathway of methylotrophic yeasts. a primary alcohol + O2 = an aldehyde + H2O2 May possess two different forms of flavin adenine dinucleotide, classical FAD and so-called modified FAD (mFAD), a stereochemical FAD analog, in which the C2 carbon of the ribityl chain has changed from the R to the S configuration. Conversion of FAD into mFAD was observed both in purified preparations of the enzyme and in cells grown in batch and continuous culture. The relative amount of mFAD in the enzyme varied from 5 to 95%, depending on the growth or storage conditions. The presence of mFAD led to a slight decrease in Vmax and a significant decrease in the KM of alcohol oxidase with respect to methanol. Energy metabolism; methane degradation. Homooctamer. Induced by methanol. Subject to strong carbon catabolite repression (By similarity). The C-terminal peroxisomal targeting signal (PTS) is essential for the efficient targeting and import of AOX into peroxisomes via the PTS1 pathway. Belongs to the GMC oxidoreductase family.