Has low pectate lyase activity. Eliminative cleavage of (1->4)-alpha-D-galacturonan to give oligosaccharides with 4-deoxy-alpha-D-galact-4-enuronosyl groups at their non-reducing ends. Binds 1 Ca(2+) ion. Glycan metabolism; pectin degradation; 2-dehydro-3-deoxy-D-gluconate from pectin: step 2/5. Expressed in pollen (at protein level). N-glycosylated; consists of complex-type N-glycans containing the Lewis a antigen (Galbeta1-3(Fucalpha1-4)GlcNAcbeta1-). Causes an allergic reaction in human. Binds to IgE of patients allergic to mountain cedar (PubMed:10482836, PubMed:10482835, PubMed:14563374, PubMed:16423400). Binds to IgE in 71% of the 14 patients tested allergic to mountain cedar. Binds to IgE in 40% of the 35 patients tested allergic to Japanese cedar (PubMed:10482835). IgE-binding is significantly reduced by heat denaturation (75 degrees Celsius), chemical denaturation (guanidine treatment) and reductive alkylation in guanidine, but not by reductive alkylation alone, indicating the presence of conformational epitopes. On the other hand, heat and guanidine-induced denaturation increases binding to a mouse monoclonal antibody KW-S91, indicative of enhanced display of the linear epitope by these treatments (PubMed:16423400). Causes proliferation of the peripheral blood mononuclear cells (PBMCs) in patients allergic to mountain cedar (PubMed:10482835). Causes seasonal allergic rhinitis in North America (PubMed:10482836, PubMed:10482835, PubMed:14563374, PubMed:16423400). Belongs to the polysaccharide lyase 1 family. Amb a subfamily.