Binds 1 FAD per subunit in a bicovalent manner. Monomer. Expressed in pollen (at protein level). The FAD cofactor is bound via a bicovalent 6-S-cysteinyl, 8alpha-N1-histidyl FAD linkage. The N-terminus is blocked. Glycosylated (PubMed:16121337). N-glycosylated (PubMed:8828524, PubMed:8900140). Contains fucose, N-acetylglucosamine, and mannose as main carbohydrates (in a ratio of approximately 3:2:1), and a minute amount of xylose (PubMed:8828524). The two most abundant oligosaccharides are Fuc(1)GlcNAc(2)Man(3) and Fuc(1)GlcNAc(2)Man(2), together comprising about 80% of the total carbohydrate content. They are structurally unusual in having a L-Fuc alpha-(1,3)-linked to Asn-linked GlcNAc without a Xyl beta-(1,2)-linked to the branching Man. The other oligosaccharides make up only 9% of the total carbohydrate content and are characterized by the presence of Xyl beta-(1,2)-linked to the branching Man (PubMed:8900140). Causes an allergic reaction in human. Binds to IgE of patients allergic to Bermuda grass pollen (BGP) (PubMed:8828524, PubMed:16121337). Binds to IgE in all 18 patients tested (PubMed:8828524). Binds to IgE in 50% of the 10 patients tested (PubMed:16121337). Periodate oxidation decreases the binding activity to IgE from 20% to 65% as the concentration of periodate increases from 1 mmol/L to 10 mmol/L, indicating the involvement of the carbohydrate moiety of this protein in immune responses (PubMed:8828524). The fucosylated glycan structures of this protein can bind the human C-type lectin receptors CD209 (DC-SIGN) and its related receptor CLEC4M (L-SIGN). The interaction provokes an immune response leading to the activation of RAF1 and ERK kinases and to the induction of tumor necrosis factor (TNF)-alpha expression in human THP-1 cells and monocyte-derived dendritic cells (MDDCs) (PubMed:20080962). Belongs to the oxygen-dependent FAD-linked oxidoreductase family.