Converts tyramine into octopamine, a neurotransmitter involved in ovulation and locomotion (PubMed:14623230, PubMed:14978721, PubMed:8656284). Functions in an amine-mediated Bacc-dependent signaling pathway that negatively regulates acute ethanol sensitivity (PubMed:23142736). Binds 2 copper ions per subunit. Present in head and in neurons innervating the oviduct (at protein level). At larval stage, present in cell bodies of the ventral ganglion and in neuropil (at protein level). Slightly down-regulated in adults fed a high calorie diet. Flies survive to adulthood. Mutant males are fertile, but mutant females are sterile due to defects in ovulation. Belongs to the copper type II ascorbate-dependent monooxygenase family.