Molecular Replacement Studies of Cucurmosin from Cucurbita Moschata: Structure Homology with Trichosanthin

摘要

High diffraction quality crystals of cucurmosin, a type Ⅰ ribosome inactivating protein isolated from the sarcocarp of Cucurbita moschata (pumpkin), have been grown under newly optimised conditions. With in-house rotating anode X-ray source, these crystals diffract to 1.65 A resolution which is much higher than that of the previously reported crystals that diffracted only to 3 A resolution. The crystals belong to space group P212121 with cell parameters a = 41.5, b = 58.4 and c = 99.3 A. Molecular replacement studies indicate that the cucurmosin structure is homologous to trichosanthin. The initial structural model has been obtained and the model fitting/refinement is in progress.