摘要：Restricted genetic diversity can supply only a limited number of elite genes for modern plant cultivation and *** this study,we demonstrate that rational design enables the engineering of geranyl-geranyl diphosphate synthase(NtGGPPS),an enzyme of the methylerythritol phosphate pathway(MEP)in the model plant Nicotiana *** the crucial bottleneck in carotenoid biosynthesis,NtGGPPS1 interacts with phytoene synthase(NtPSY1)to channel GGPP into the production of *** of this enzyme in the ntggpps1 mutant leads to decreased carotenoid *** the aim of enhanc-ing NtGGPPS1 activity,we undertook structure-guided rational redesign of its substrate binding pocket in combination with sequence *** activity of the designed NtGGPPS1(a pentuple mutant of five sites V154A/I161L/F218Y/I209S/V233E,d-NtGGPPS1)was measured by a high-throughput colorimetric assay.d-NtGGPPS1 exhibited significantly higher conversion of IPP and each co-substrate(DMAPP~1995.5-fold,GPP~25.9-fold,and FPP~16.7-fold)for GGPP synthesis compared with wild-type ***,the transient and stable expression of d-NtGGPPS1 in the ntggpps1 mutant increased carotenoid levels in leaves,improved photosynthetic efficiency,and increased biomass relative to *** findings provide a firm basis for the engineering of GGPPS and will facilitate the development of quality and yield *** results open the door for the structure-guided rational design of elite genes in higher plants。

摘要：The mitogen-activated protein kinase （MAPK） cell signal transduction pathways play a key role in determining the survival of cells. If these pathways can be controlled, they will prohibit the proliferation of cancer cells. To attain this goal, the authors utilize many drugs to interact with mitogen-activated protein kinase kinase-1 （MEK1） in MAPK, and use computer aided drug design （CADD） to analyze the ligand activities of proteins in MEKL The results show that in these drugs, the aromatic group in the terminal of the protein and the PHE209 will induce the stacking force, which is highly related to the actual activities of these drugs.