小麦COXVIIa基因克隆及其蛋白序列分析  

Cloning and Sequence Analysis of COXVIIa Gene in Wheat

作　　者：范小芳[1] 王俊生[1] 刘红占[1] 周琳[1] 王晓娟[1] 赵锦慧[1] 

机构地区：[1]周口师范学院生命科学与农学学院,河南466001

出　　处：《分子植物育种》2016年第2期271-279,共9页Molecular Plant Breeding

基　　金：河南省科技攻关项目(152102110106);教育厅重点攻关项目(14B210022)共同资助

摘　　要：为研究小麦(Triticum aestivum L.)细胞色素C氧化酶复合蛋白结构与功能关系,本研究采用电子克隆和RT-PCR技术克隆了一个小麦细胞色素C氧化酶7a亚基(COXVIIa)基因的c DNA序列,并以生物信息学方法对其翻译的蛋白质及相应垂直同源蛋白质序列进行了比较和鉴定,模建了其三级结构,分析了其与被子植物中同源蛋白质之间的进化关系。结果表明,小麦COXVIIa基因的c DNA序列长494 bp,包含一个210 bp长的开放阅读框,编码69个氨基酸组成的多肽。亚细胞定位预测结果表明,该蛋白与其垂直同源蛋白均定位于线粒体中。在小麦COXⅦa蛋白序列中,36~58 aa形成一个跨膜螺旋区,且1~35 AA(N端)位于膜外,59~69AA(C端)位于线粒体内部;模建的三级结构主要由2段α螺旋结构组成,属于全α型蛋白,与其二级结构预测结果一致。基因表达分析表明该基因在叶鞘中不表达,而在其他组织中均不同程度的表达;在花、花冠和花序组织中具有较高的表达量。进化分析表明,小麦COXⅦa蛋白与乌拉尔图小麦(Triticum urartu)、大麦、二穗短柄草(Brachypodium distachyon)和玉米等单子叶植物进化距离较近,与油菜、玉山筷子芥(Arabidopsis lyrata subsp.Lyrata)、大豆、杨树、蒺藜苜蓿(Medicago truncatula)等双子叶植物的进化距离较远,COXⅦa在这些被子植物中具有较强的保守性。本研究为揭示小麦COX蛋白复合物的结构和功能提供了理论依据。In order to study the relationship between structure and function of Cytochrome c Oxidase(COX) from wheat(Triticum aestivum L.), a Cytochrome c Oxidase 7a subunit(COXVIIa) gene was cloned by using electronic cloning and reverse transcription polymerase chain reaction(RT-PCR). The translated COX Ⅶa protein and the sequence of its ortholog from angiosperm were compared and characterized by bioinformatics method. In this study tertiary structure of the wheat COX Ⅶ a protein was modeled, and the evolution relationships between the wheat COX Ⅶ a protein and its orthologs in angiosperms were analyzed. The results showed the wheat COXVIIa sequence consists of 494 bp with an intact opening reading frame(ORF) of 210 bp in length, encoding a polypeptide of 69 amino acids residues. Subcellular localization analysis proved that the protein and its ortholog from other angiosperm were targeted to the mitochondria, In the protein sequence of COXVIIa in wheat, the 36 ~ 58 amino acids formed a transmembrane helical region, of which the 1~35 amino acids(N-terminal sequences) located outside of the mitochondrial inner membrane and the 59~69 amino acids(C-terminal sequences) located inside of membrane.The modeled tertiary structure consisted of 2 pieces of α-helix. It was the same as the result of the secondary structure predicted. Gene expression analysis showed the wheat COXVIIa gene expressed in different tissues except in sheath, its expression patters were different in different tissues or organs. Homology analysis showed that the protein sequence was highly homologous to their orthologs from other species. Phylogenetic tree analysis Molecular Plant Breeding indicted that the protein should be very close to the orthologs from the monocotyledons, such as Triticum urartu,Hordeum vulgare subsp. vulgare, Brachypodium distachyon and far from the dicotyledons, such as Brassica napus L., Arabidopsis lyrata subsp. lyrata, Glycine max, Medicago truncatula, Populus trichocarpa. The study might provide a theory support for revealin

关 键 词：小麦 细胞色素C氧化酶 基因克隆 序列分析 

分 类 号：S512.1[农业科学—作物学]