摘要：在线粒体基因组中，被称为“条形码基因”的CcOI，含有丰富的遗传信息，其基因变异相对较大，系统解析能力较强。用生物信息学方法模建其高级结构对揭示其生物学功能意义重大。本课题通过下载油菜线粒体CcOI蛋白亚基序列，分别从序列的理化性质、亚细胞定位、跨膜与疏水性、电子表达与保守域、高级结构及进化等方面进行了预测和分析，探讨油菜中线粒体CcOI蛋白亚基的相关功能信息。结果表明，油菜线粒体CcOI蛋白亚基是一个亲水性较强的稳定蛋白，在线粒体内膜上形成12个跨膜区，在该蛋白亚基中，α螺旋占比31.31%，无规则卷曲占比30.17%。跨膜螺旋以近似三重轴对称方式排列在膜中。进化树分析表明，油菜线粒体CcOI蛋白亚基与拟南芥和密花独行菜进化距离最近，同源比较和进化树分析均表明油菜CcOI蛋白亚基与其它物种同源蛋白相似性非常高，序列保守性强。

关键词：油菜；线粒体；CcOI蛋白亚基；结构模建

 Advanced structure model of mitochondrial CcO I protein subunits from Brassica napus L

Abstract: CcO I was known as the "barcode gene", it is in the mitochondrial genome and it showed rich genetic information. Its variation is relatively large and it plays very important roles in life activities.  It is significant to understand its biological function of the CcO I protein from Brassica napus through modeling its advance structural by bioinformatics methods, In this study, we downloaded the CcO I protein subunit incoded by mitochondrial DNA, and predicted and analyzed its physical and chemical properties, subcellular localization, transmembrane and hydrophobicity, electron expression and conserved domain, advanced structure and evolution etc. Correlation function informations of mitochondrial CcO I protein subunit in Brassica napus were also discussed in the paper. The result showed that mitochondrial CcO I protein subunit is a highly hydrophilic stable protein, 12 transmembrane regions were formed in the inner mitochondrial membrane. In the secondary structure of the protein subunit, alpha helix accounts for 31.31%, random coil accounts for 30.17%.The transmembrane helix is arranged in a film with an approximate three fold axis symmetry. Evolutionary tree indicated that Rapeseed mitochondrial CcO I protein subunits was close in evolutionary relationships with that of Arabidopsis thaliana and Lepidium densiflorum. The homology comparison and evolutionary analysis showed that CcO I protein subunit of rapeseed has high similarity with that of other species , they are highly conserved in protein sequences.

Keywords: Brassica napus L; mitochondrial; CcO I protein subunit; modeling

目录

摘要 1

引言 2

1．材料和方法 3

1.1序列来源数据库 3

1.2生物信息学分析方法及软件 3

1.2.1理化性质预测结果 3

1.2.2跨膜与疏水性分析 3

1.2.3基因的电子表达和保守域分析 3

1.2.4高级结构预测与评价分析 4

1.2.5同源比较和进化分析 4

2．结果与分析 4

2.1油菜线粒体CcOI蛋白亚基的理化性质分析 4

2.2油菜线粒体CcOI蛋白亚基的跨膜与疏水性分析 4

2.3油菜线粒体CcOI蛋白亚基序列的电子表达与保守结构域分析 6

2.4油菜线粒体CcOI蛋白亚基的高级结构预测与评价分析 7

2.4.1二级结构预测分析 7

2.4.2三级结构预测及对预测结果的评价分析 7

2.5油菜线粒体CcOI蛋白亚基的同源序列比较和进化分析 9

2.5.1同源序列比较 9

2.5.2进化分析 10

3.结论与讨论 11

参考文献 12

致谢 13

油菜线粒体CcOI蛋白亚基的高级结构模建

引言

在生物体的氧化磷酸化过程中，细胞色素c氧化酶作为真核生物线粒体内膜电子传递链上的终端酶发挥着重要的作用[1]。细胞色素c氧化酶在哺乳动物中含13个亚基，而在细菌中一般为3-5个，是一个由多亚基构成的膜蛋白，其中的亚基I、II、III被称为核心亚基，因为它们在哺乳动物和细菌中高度保守且相似性极高[2]。然而，在Paracoccusdenitrificans的CcO中只包含亚基I和亚基II，但是也可以进行完整的电子传递过程且具有完全的质子泵活性。