玉米寡肽转运蛋白基因(ZmOPT0212)的克隆及其生物信息学分析

Cloning and Bioinformatic Analysis of Oligopeptide Transporter Gene of Maize(Zea mays L.)

根据玉米B73和水稻的寡肽转运蛋白全长序列设计引物,通过RT-PCR直接扩增的方法从玉米自交系478中克隆到了寡肽转运蛋白基因,命名为ZmOPT0212(Accession number:HM021150)。ZmOPT0212开放阅读框为2 151bp,编码716个氨基酸残基,等电点8.87,相对分子质量为77.4 kDa。预测由该基因转录的寡肽转运蛋白其二级结构约含43.85%的α-螺旋、13.27%的延伸链、3.91%的β-转角和38.97%的不规则卷曲,含有14个连续的疏水片断,其中12个可能构成跨膜螺旋;预测该转运蛋白不存在信号肽,亚细胞定位存在于细胞膜上。同源性和进化树的预测分析显示,ZmOPT0212蛋白与水稻、拟南芥、毛果杨和蓖麻等高等植物的寡肽转运蛋白同源性分别达到了99%,96%,92%和92%,所转运的底物除有寡肽外,还包含有金属离子、金属离子-烟草胺的螯合物等。

The cDNA of Oligopeptide transporter gene from nitrogen-sensitive maize inbred lines named ZmOPT0212（Accession number：HM021150）was isolated by RT-PCR,with primers designed according to the sequence of Oligopeptide transporter full-length gene in maize inbred line B73 and rice.The largest open reading frame of ZmOPT0212 gene has 2 151 bp in length and encoded a polypeptide of 716 amino acid residues.The estimated molecular weight and isoelectric point of the putative protein were 77.4 kDa and 8.87,respectively.The predicted secondary structure composition for the protein has about 43.85% alpha helixes,13.27% extended strand,3.91%beta turn and 38.97%random coil.Hydrophobicity/hydrophilic analysis indicated that the ZmOPT0212 had 14 hydrophobic segments containing 12 potential transmembrane segments,the ZmOPT0212 had no signal peptide,was located on Plasma Membrane.Blast result and the phylogenetic tree analysis showed that peptide encoded by ZmOPT0212 of maize inbred lines 478 had high identity with the Oligopeptide transporter of the rice,Arabidopsis thaliana,Populus trichocarpa,Ricinus communis and had about 99%,96%,92%and 92%similarity respectively.The substrates for these transporters include oligopeptide metal ions,metal-nicotianamine and so on.