中文摘要：

NAD/NADP-苹果酸酶（NAD-ME/NADP-ME）是C4植物光合途径的关键酶。采用RT-PCR技术对籽粒苋NAD-ME基因进行克隆,获得了籽粒苋NAD-ME基因的cDNA序列。结果表明,该序列开放可读框长度为1 872 bp,编码623个氨基酸;多序列比对和进化树分析表明,该基因核苷酸序列与其他植物已报道的NAD-ME/NADP-ME基因的核苷酸序列一致性高达75.1%-80.6%,其氨基酸序列与其他植物的NAD-ME/NADP-ME蛋白一致性为73.2%-80.3%。对推断氨基酸序列的蛋白保守区、疏水性/亲水性、潜在跨膜片段、信号肽、蛋白固有无序化和蛋白二级结构分析表明,该蛋白具有苹果酸酶的保守区、兼具亲水性和疏水性,并且含有无序结构域,可能是一种跨膜的非分泌性蛋白。

英文摘要：

NAD/NADP-malic enzyme is a key enzyme in C4 photosynthetic pathway.The NAD-ME gene of Amaranthus hypochondriacus was cloned by RT-PCR.According to the analysis of the sequence,the cDNA included a 1 872 bp open reading frame that encoded 623 amino acids.Multi-sequence comparisons and phylogenetic analysis showed that the nucleotide sequence had 75.1%-80.6% identity with the reported NAD-ME/NADP-ME genes of other plants,and the amino acids sequence had 73.2%-80.3% identity.Furthermore,the physico-chemical property of NAD-ME of Amaranthus hypochondriacus,including the conservative domains,hydrophobicity/hydrophilicity,potential transmembrane segments,signal peptides,intrinsically disordered structure and secondary structure of the hypothetical protein were analyzed.The results suggested that the protein contained conservative domains of NAD-ME,both hydrophobic and hydrophilic regions,and also the disordered regions.Thus it seems a non-secreted transmembrane protein.