Lithocarols类化合物生物合成基因litI的表达及其启动子功能分析OA北大核心CSTPCD

[Objective]Lithocarols are a novel class of polyisoprenyl diphenylketone compounds,which have a good antitumor activity.The lithocarols biosynthesis gene litI was cloned,expressed and purified,the promoter of the gene litI was functionally identified,which will lay a molecular foundation for the biosynthesis and transcriptional regulation of lithocarols.[Method]The biosynthetic gene litI was cloned and expressed in Escherichia coli,and the expressed protein LitI was preliminarily purified by nickel affinity chromatography column.The properties and structure of the protein were analyzed by bioinformatics method.The litI gene promoter fragment was amplified,the luciferase expression system was constructed to analyze the transcriptional activity of the promoter,and its functional components were predicted by the PlantCARE promoter analysis website.[Result]LitI protein is a hydrophilic protein,which has a relative molecular weight of 51 kD and a secondary structure including 51.32%α-helix,8.99%extended chain,3.95%β-angle,and 35.75%irregular curling.The gene litI promoter shows strong transcription activity,and it could initiate the transcription of ampicillin resistance gene in E.coli,and litI promoter contained TATA box and CAAT box.[Conclusion]LitI protein is obtained by heterologous expression,its properties and structure are analyzed,and the promoter fragment of litI gene with strong transcription activity is identified.