三角梅SOD基因家族成员的克隆与生物信息学分析

The cDNA Cloning and Bioinformatics Analysis of SOD Gene Family in Bougainvillea

SOD基因家族在植物对抗活性氧破坏细胞膜透性及保护细胞膜完整性中有着重要作用。本研究以伊丽莎白·安格斯(Bougainvillea glabra"Elizabeth Angus")为模板,得到了Fe-SOD基因保守序列片段及Cu/ZnSOD和Mn-SOD基因全长序列,其中,胞质型CSD共2种编码类型:cy CSD1型和cy CSD2型,其分子式分别为C_(920)H_(1507)N_(265)O_(298)S_(17)和C_(863)H_(1415)N_(249)O_(272)S_(15),开放阅读框(ORF)全长分别为585 bp和543 bp,编码氨基酸长度分别为194个和180个,蛋白相对分子量分别为21.59 k D和20.11 k D,理论等电点(p I)分别为8.12和9.16,皆属不稳定的碱性疏水蛋白;Mn-SOD具有711 bp ORF,编码236个氨基酸,相对分子量为26.33 k D,分子式为C_(1191)H_(1849)N_(321)O_(340)S_7,p I为7.84,属稳定的偏碱性疏水蛋白。膜结构预测结果表明,cy CSD 1型蛋白可能与cy CSD 2型蛋白皆可能存在2个跨膜螺旋,长度分别为17个和19个氨基酸,17个和21个氨基酸;MSD蛋白没有发现跨膜结构域,可能不存在跨膜螺旋。亚细胞定位结果表明,cy CSD蛋白推定定位在细胞质膜;MSD蛋白定位于线粒体质膜。研究推测,所得基因序列为三角梅SOD基因家族成员。

The SOD gene family plays an important role in plant response to reactive oxygen species （ROS） destruction of cell membrane permeability and protection of cell membrane integrity. In this study, Bougainvillea glabra ＂Elizabeth Angus＂ was set as the template, and the conserved sequence fragments ofFe-SOD gene and the full length sequence of Cu/Zn-SOD and Mn-SOD gene were obtained. There were 2 coding types of cytoplasmic CSD： type cyCSD1 and type cyCSD2. Their molecular formulas were C920H1507N265O298S17 and C863H1415N249O272S15, respectively. The length of ORFs were 585 bp and 543 bp, encoding 180 and 236 amino acids with molecular weights of 21.59 kD and 20.11 kD and isoelectric points of 8.12 and 9.16 respectively, and they were both unstable alkaline hydrophobic proteins. The molecular formula of Mn-SOD was ClI91H1849N321O340S7, whose ORFs was 711 bp, encoding 236 amino acids with molecular weight of 26.33 kD and isoelectric points of 7.84, and it belonged to stable alkaline hydrophobic protein. Results of membrane structure prediction showed that cyCSD1 and cyCSD2 might have two transmembrane helices, encoding 17 and 19 amino acids, and 17 and 21 amino acids, respectively.However, no transmembrane domain was found in MSD, so it might not have transmembrane helice. Results of subcellular localization indicated that cyCSD and MSD were located in the cytoplasmic membrane and mitochondrial membrane, respectively. In conclusion, we speculated that those obtained gene sequences might be the members of SOD gene family in Bougainvillea glabra.