郑麦366α-醇溶蛋白基因的克隆及生物信息学分析

Cloning and Bioinformatic Analysis of α-gliadin Genes in Zhengmai 366

为研究优质强筋小麦品种郑麦366α-醇溶蛋白的组成,应用简并引物进行PCR扩增,从郑麦366中扩增得到13条核苷酸序列,其中9条序列推导的氨基酸序列具有完整的开放阅读框。进一步分析显示,克隆的9个基因(分别命名为ZM366-1—ZM366-9)编码的蛋白质均具有α-醇溶蛋白的典型结构特征,根据T-细胞毒性抗原表位数目和多聚谷氨酰胺区特征分别将ZM366-1、ZM366-2定位到6A染色体,ZM366-3、ZM366-4定位到6D染色体,ZM366-5—ZM366-9定位到6B染色体。蛋白质二级结构预测显示,克隆的9个α-醇溶蛋白都仅含有α-螺旋结构,其中B基因组α-醇溶蛋白的α-螺旋含量明显高于其他基因组。同源系统进化树分析表明,克隆的9个α-醇溶蛋白具有明显的基因组特异性。

To reveal the composition of α -glia din protein in high quality and strong gluten wheat variety Zhengmai 366,the PCR amplification were appl ied to clone a-gliadin genes in Zhengmai 366 with degen-erate primers. In total, 13 nucleot ide sequences were amplified, while the deduced amino acid sequences of nine encoded complete open reading frames. Further analysis showed that the cloned genes （ named as ZM366-1- ZM366-9 respectively ） had the typical characteristics of α-gliadin . According to the number of T cell stimulatory toxic epitopes and the characteristics of polyglutamine domain, ZM366-1 and ZM366-2, ZM366-3 an d ZM366-4 an d ZM366-5- ZM366-9 were localized to the 6 A ,6 D and 6B chromosome re -spectively. Secondary structure prediction showed that all the nine a-gliadin cloned in the present study only contained α- helix structure, and the content of α-helix was significantly higher in α-gliadin of B ge-nome than that of others. Phylogenetic tree analysis showed that the cloned α-gliadin of present study had obvious genomic specificity.