【摘要】 通过调节蔗糖代谢途径中的协同因子无机焦磷酸(PPi)可以调控马铃薯块茎的休眠和发芽特性。本研究将马铃薯无机焦磷酸酶(PPase)基因(GenBank Accession No.:EF091820)与载体pET-28a融合,构建了原核表达载体pET-PPA,然后导入大肠杆菌BL21(DE3)中,经SDS-PAGE分析表明PPase基因在大肠杆菌中能够表达。用生物学软件对PPase基因及其编码的蛋白质分析表明,该PPase基因与与茄属的同源性高达89%~97%,与其他物种PPase基因的同源性在77%~80%之间;系统进化树分析表明PPase与茄科茄属和藜科甜菜属的进化类群最接近;其编码的蛋白质具有多个磷酸化位点,没有跨膜区;蛋白质二级结构预测显示,有63个氨基酸可能形成α-螺旋结构,38个氨基酸可形成延长链;通过亚细胞定位可知,它主要是一种细胞质和线粒体基质蛋白。更多还原

【Abstract】 The characteristics of potato tuber dormancy and sprouting could be controlled by regulating inor- ganic pyrophosphate (PPi), which is a co-factor in tuber sugar metabolism. The prokaryotic expression vector pET-PPA was constructed by fusing potato inorganic pyrophosphatase (PPase) gene (GenBank accession No.: EF091820) with vector pET-28a, and introduced into Escherichia coli BL21 (DE3). The result of SDS-PAGE analysis showed that the PPase gene could express in E. coli. The analysis of biological software showed that the nucleotide sequence of the PPase gene shared 89%~97% identity to Solanum, and 77%~80% identity to other plants. Phylogenetic tree based on the nucleotide sequence alignment showed the PPase gene was closed to Solanum and Beta vulgaris species. The PPase protein had several phosphorylation sites, and without trans- membrane region, and alpha helix with 63 amino acids and extended strand with 38 amino acids, which was mainly a kind of protein existed in cytoplasm and mitochondrial matrix space.更多还原