 The binding pocket of the 5-methoxy group is more investigated than the other pocket.Researchers agree that the oxygen in the group binds to histidine (His) residues in transmembrane 5 (TM5) domain of the receptor with a hydrogen bond; His195 in MT1 and His208 in MT2.Another amino acid, valine 192 (Val), also participates in the binding of the 5-methoxy group by binding to the methyl portion of the group.