Abstract:Bioinformatic methods were employed to analyze the amino acid sequences of Δ12-fatty acid desaturase(FAD2), the key synthetase of polyunsaturated fatty acid in different plants. The results were as bellow: FAD2 belongs to a type of unstable protein, containing 3 highly conserved His-Boxes. Phylogenetic tree reveals the close relationship between woody oil plants. There are no transit peptides in amino acid sequence but 4 transmembrane domains, which is consistent with the predictions to hydrophobic domains. Random coils are the major structural elements of polypeptide chain. There are Delta12-FADS-like structures in the conserved domains of SsFAD2. The protein could be phosphorylated by protein kinase C, with the potential phosphorylated site Ser140. This study could privide guidelines to the studies of the enzymatic properties of FAD2 and the mechanisms under the biosynthesis of polyunsaturated fatty acids.