麻疯树油质蛋白家族基因的鉴定序列与进化分析
毕业论文关键词：麻疯树；油质蛋白；基因家族；序列；进化分析
Identification, Sequence and Evolutionary Analysis of the Oleosin family Genes in Jatropha curcas
Abstract: Oleosin is a membrane protein localized on the oil body, which plays important roles in oil body formation and stability. 6 JcOLE genes were identified using bioinformatics method, sequence and evolutionary features of which were analyzed in detail. Phylogenetic analysis showed that all the JcOLE genes were pided into four groups, and two pairs of homologous genes were found in the end of the phylogenetic tree. Sequence analysis indicated that all the OLE genes have three types of gene structure, that all the OLE proteins have three types of conserved motif organization patterns, and that these proteins share the same functional domain. Additionally, 21 conserved amino acid sites were identified and mapped in the OLE domain, and they are closely associated with the function of OLE proteins. Selective pressure analysis demonstrated that JcOLE5 and JcOLE6 were under negative selection, and that JcOLE1 and JcOLE2 were under positive selection, suggesting adaptive evolution were found in the JcOLE1 and JcOLE2. These results provide a good basis for further investigating the biological function of the OLE family protein in Jatropha curcas.
Key words: Jatropha curcas, Oleosin, Gene family, Sequence, Evolutionary analysis
目 录
摘要 2
引言 2
1 材料与方法 4
1.1 数据来源与序列检索 4
1.2 序列比对与系统进化分析 4
1.3 基因结构与蛋白特性分析 4
1.4 同源基因对的选择压力检测 4
1.5 麻疯树OLE蛋白保守氨基酸位点的预测 5
2 结果与分析 5
2.1 麻疯树与植物油质蛋白基因的鉴定与物种分布特征 5
2.2 麻疯树与植物OLE基因的联配与系统进化关系 7
2.3 麻疯树OLE基因的结构特征 8
2.4 麻疯树OLE蛋白的保守基序组成模式 9
2.5 麻疯树同源基因对的适应性进化 10
2.6 麻疯树OLE基因的保守氨基酸位点 10
3 讨论与结论 11
参考文献 12
附录 16
致谢 16
麻疯树油质蛋白家族基因的鉴定、序列与进化分析引言
植物脂类是植物种子储存能量最重要、有效的形式，广泛存在于开花植物的种子、花粉、根、茎、花中，存在于非开花植物的孢子和营养器官中，在植物生长与发育过程中扮演重要的作用[1-2]。脂类物质主要以三酰甘油的形式储藏在种子油体中，油体内部主要为三酰甘油酯的液态基质，外部则为磷脂单分子层，且这种半单位膜上镶嵌着几种结合蛋白[3-5]。一般认为，油体表面的结合蛋白包括油质蛋白、油体钙蛋白、油体固醇蛋白和未鉴定新蛋白质。令人感兴趣的是，油质蛋白是油体结合蛋白中发现最早，含量最丰富的一类蛋白。研究表明：油质蛋白对油体的形成与稳定具有十分重要的作用；油质蛋白在种子萌发、发育、成熟和休眠的过程中发挥重要作用[6]。新近几年，种子油体表面结合蛋白可以与目标蛋白融合表达，通过富集油体生产和提纯目标蛋白，而这种结合蛋白正是油质蛋白，因此，对植物油质蛋白的研究越来越受到人们的重视[7]。
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