毛偃麦草Na^+/H^+逆向转运蛋白的分子克隆及生物信息学分析  

Molecular Cloning and Bioinformatics Analysis of a Vacuolar Na^+/H^+ Antiporter Gene in Elytrigia trichophora

作　　者：关宁[1] 李聪[1] 王涌鑫[1] 苗丽宏[1] 

机构地区：[1]中国农业科学院北京畜牧兽医研究所牧草遗传育种研究室,北京100193

出　　处：《分子植物育种》2009年第1期169-176,共8页Molecular Plant Breeding

基　　金：国家十一五科技支撑计划(2006BAD01A19);中国农科院院所基金(ywf-td-03)资助

摘　　要：根据小麦和长穗偃麦草的液泡膜Na+/H+逆转运蛋白基因(TaNHX1、TeNHX1)全长序列设计引物,通过RT-PCR直接扩增的方法从毛偃麦草(Elytrigia trichophora L.)中克隆到了Na+/H+逆转运蛋白基因,命名为EtNHX1(Accession numeber:EU876834)。EtNHX1最大开放阅读框为1641bp,编码含有546个氨基酸残基、分子量为59.8kD的蛋白,预测等电点8.0。EtNHX1含有39个碱性氨基酸,37个酸性氨基酸,256个疏水氨基酸及128个极性氨基酸。二级结构预测表明该蛋白含约47%的α-螺旋、20%的延伸链、4.5%的β-转角和28%的不规则卷曲。亲疏水性分析显示,EtNHX1含有12个连续的疏水片断,其中10个可能构成跨膜螺旋。序列分析显示,EtNHX1与小麦(Triticum aestivum L.)、中间偃麦草(Thinopyrum intermedium L.)、长穗偃麦草(Elytrigia elongate L.)、水稻(Oryza sativa L.)、角果碱蓬(Suaeda corniculata L.)、小盐芥(Thellungiella halophila L.)等植物的液泡膜Na+/H+逆向转运蛋白高度同源,序列相似性分别为98%、98%、96%、85%、68%和67%。序列比对结果以及进化树分析均表明EtNHX1应为定位于毛偃麦草液胞膜上的Na+/H+逆向转运蛋白。The cDNA of Na^＋/H^＋ antiporter gene from Elytrigia trichophora named EtNHX1 （Accession numeber： EU876834） was isolated by RT-PCR, with primers designed according to the sequence of TaNHX1 and TeNHX1. The largest open reading frame ofEtNHX1 gene has 1 641 bp in length and encoded a polypeptide of 546 amino acid residues. The estimated molecular weight and isoelectric points of the putative protein were 59.8 kD and 8.0, respectively. Components of amino acids encoded by EtNHX1 contained 39 basic amino acids, 37 acidic amino acid, 256 hydrophobic amino acids and 128 polar amino acids. The predicted secondary structure composition for the protein has about 47% alpha helixes, 20% extended strand, 4.5% beta turn and 28% random coil. Hydrophobicity/hydrophilic analysis indicated that the EtNHX1 had 12 hydrophobic segments containing 10 potential transmembrane segments. Sequencing analysis showed that EtNHX1 had high identity with TaNHX1, TiNHX1, TeNHX1, OsNHX1, ScNHX1, ThNHX 1, and had about 98%, 98%, 96%, 85%, 68%, and 67% similarity respectively. Blast result and the phylogenetic tree analysis showed that EtNHX1 was Na^＋/H^＋ antiporter located on vacuolar of Elytrigia triehophora.

关 键 词：毛偃麦草 NA+/H+逆向转运蛋白 生物信息学 

分 类 号：S54[农业科学—作物学]