3种棱型大麦中脱水素6(DHN6)的性质、突变位点与蛋白质进化分析  

Analysis of Characters,Mutatant Sites and Evolution of Protein of Dehydrin 6(DHN6) in 3 Typical Rowed Barleys

作　　者：钱刚[1] 平军娇[1] 张珍[1] 王乾兴[1] 刘茂生[2] 

机构地区：[1]遵义医学院细胞生物学与遗传学教研室,遵义563000 [2]遵义医学院解剖学教研室,遵义563000

出　　处：《基因组学与应用生物学》2011年第3期322-329,共8页Genomics and Applied Biology

基　　金：贵州省科学技术基金项目(黔科合J字[2007]2050号);贵州省遵义市科学技术基金项目(遵市科合农字2007-05号)共同资助

摘　　要：脱水素(dehydrins,DHNs)是高等植物胚胎发育晚期产生的一类特异多肽,能够逆转细胞脱水所造成的伤害。为明确脱水素性质与功能的关系,本研究从3种棱型大麦分离到Dhn6基因,生物信息学分析其编码的蛋白质序列长度分别为523个(六棱)、502个(四棱)和486个(二棱)氨基酸残基;氨基酸突变位点分析发现该基因具有整体保守性和突变位点偏倚性。蛋白质性质与二级结构分析表明,DHN6是高度亲水的碱性蛋白质,线性结构和自由卷曲为二级结构的主要组分,K-片段参与α-螺旋结构的形成,由此推测DHN6的兼性α-螺旋结构域在稳定膜结构的水合保护体系过程中发挥着重要的生理功能。构建的21个物种DHN6蛋白质系统发生树,发现禾本科植物遗传距离较近,结合核苷酸序列的物种特异性,本研究认为Dhn6基因可作为物种鉴定依据。Dehydrins（DHNs）,a special polypeptide generated in late embryogenesis of higher plants,could protect the plants from the damage caused by cell dehydration.In order to learn the relationship between characteristics and functions of dehydrins,we extracted Dhn6 genes from 3 typical rowed barleys,and used bioinformatics analysis to find their encoded proteins were composed of 523（six-rowed barley）,502（four-rowed barley） and 486（two-rowed barley） amino acid residues,respectively.Furthermore,we found there were whole conservative traits and mutant sites specificity in this gene by analysis of amino acid mutations.Analyses of characteristics and secondary structure indicated that DHN6 consisted of highly hydrophilic alkaline proteins primarily,and the secondary structure consisted of linear structure and numerous random curls.Moreover,the amphipathic α-helices formed by K-segments might play important roles in protecting membrane structure.The phylogenetic tree of 21 species in this study agreed with the view that Dhn6 gene could be an efficient foundation for identifying and distinguishing of different species associated with special sequences of nucleotides,and closer genetic distance was discovered in gramineae crops.

关 键 词：大麦 Dhn6基因 序列比对 二级结构 系统进化 

分 类 号：S512.3[农业科学—作物学]