玉米磷酸烯醇式丙酮酸羧化酶（PEPC）基因的克隆及序列分析

目的]获得玉米的PEPC基因,并对其生物信息学进行分析。方法]使用RT-PCR方法由玉米中获得PEPC全长c DNA,构建克隆载体后进行测序,并对其序列进行生物信息学分析。结果]获得的玉米PEPC基因CDS全长2 913 bp,编码的多肽链包含970个氨基酸,为疏水性氨基酸,由α-螺旋(61.44%)、无规则卷曲(34.43%)和延伸链(4.12%)组成,定位于细胞质,不存在跨膜结构域,其175~970位氨基酸组成了磷酸烯醇式丙酮酸羧化酶的功能结构域,在173~184、597~609位具有2个磷酸烯醇式丙酮酸羧化酶活性位点。结论]该研究克隆了玉米C_4型丙酮酸磷酸双激酶(PPDK)基因,它所编码的氨基酸序列具备PPDK蛋白的保守序列和催化活性中心区域。

Cloning and Bioinformatics Analysis of Phosphoenolpyruvate Carboxylase(PEPC) in Maize

Objective] To clone the phosphoenolpyruvate carboxylase(PEPC) gene obtained from Zea mays and analyze it by bioinformatics. Method] Primarily, the cDNA clone was constructed by RT-PCR amplified with the gene specific primers, then positive clones were se-quenced and analyzed by bioinformatics. Result] The electrophoresis showed that the coding sequence( CDS) of PEPC gene in Zea mays was 2 913 bp and the polypeptide chains coded by PEPC included 926 amino acids, which were hydrophobic amino acids consists of-helix (61.44%), random coil (34.43%) and extended strand (4.12%), with located in the cytoplasm.There was no transmembrane domain. The 175-970 amino acid composition the functional domains of phosphoenolpyruvate carboxylase, in 173-184;597-609 bits had two phos-phoenolpyruvate carboxylase active site with pyruvate orthophosphate dikinase basing on amino acids sequences comparison. Conclusion] The PEPC gene in Zea mays has been obtained and the amino acids sequence coded by the gene was conserved and contained active catalyst central site of PEPC.