硫酯酶SgcE10的初步晶体学分析

ntibiotics are widely used medicines. They are used in human healthcare, agriculture, animal husbandry and fishery. Since its first appearance in 1940s, signifcant improvement has been made in the antibiotic production. Antibiotics mainly come from Streptomyces, which produce a lot of secondary metabolites. Enediyne is produced by Streptomyces globisporus. It is proved to have antitumor and antimicrobial activity. Although it has not been put in clinical use, increasingly amount of research about this compound has been performed. SgcE10 is involed in the biosyntheis of Enediyne. It is predicted to be a thioesterase and belongs to the Hot-dog superfamily. In this work, I transformed the vector pET28a-sgcE10 into E.coli BL21 competent cells, and induced it to express protein. A large amount of pure proteins SgcE10 was obtained by affinity chromatography, gel filtration chromatography. The purefied protein was used for crystallization and the resulting crystals were used for X-ray diffraction experiments. Then the diffraction data was processed and the SgcE10 structure was built accordingly. The maximum resolution is 2.90 ?, the space group is P 1 21 1, and the cell parameters are a=58.47, b=182.32, c=61.38, α=90.00, β=94.73, γ=90.00. In the crystal structure, SgcE10 forms a octamer.