Phospholipase A2 releases fatty acids from the second carbongroup of glycerol. Perhaps the best known members are secretedsnake venoms, but also found in secreted pancreatic andmembrane-associated forms. Structure is all-alpha, with two coredisulfide-linked helices and a calcium-binding loop. Thisalignment represents the major family of PLA2s. A second minorfamily, defined by the honeybee venom PLA2 PDB:1POC and relatedsequences from Gila monsters (Heloderma), is not recognised.This minor family conserves the core helix pair but issubstantially different elsewhere. The PROSITE pattern PA2_HIS,specific to the first core helix, recognises both families. Phospholipase A2 Phospholip_A2_1