Department of Biology, Faculty of Science, Karadeniz Technical University, Trabzon, Turkey.
J Microbiol Biotechnol. 2012 Jan;22(1):133-40. doi: 10.4014/jmb.1108.08061.
A novel cry2Ab gene was cloned and sequenced from the indigenous isolate of Bacillus thuringiensis subsp. kurstaki. This gene was designated as cry2Ab25 and its sequence revealed an open reading frame of 1,902 bp encoding a 633 aa protein with calculated molecular mass of 70 kDa and pI value of 8.98. The amino acid sequence of the Cry2Ab25 protein was compared with previously known Cry2Ab toxins, and the phylogenetic relationships among them were determined. The deduced amino acid sequence of the Cry2Ab25 protein showed 99% homology to the known Cry2Ab proteins, except for Cry2Ab10 and Cry2Ab12 with 97% homology, and a variation in one amino acid residue in comparison with all known Cry2Ab proteins. The cry2Ab25 gene was expressed in Escherichia coli BL21(DE3) cells. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed that the Cry2Ab25 protein is about 70 kDa. The toxin expressed in BL21(DE3) exhibited high toxicity against Malacosoma neustria and Rhagoletis cerasi with 73% and 75% mortality after 5 days of treatment, respectively.
从苏云金芽孢杆菌亚种库斯塔克氏菌的本土分离株中克隆并测序了一个新型 cry2Ab 基因。该基因被命名为 cry2Ab25，其序列显示出一个开放阅读框，长 1902bp，编码一个 633 个氨基酸的蛋白质，计算分子量为 70kDa，等电点为 8.98。Cry2Ab25 蛋白的氨基酸序列与先前已知的 Cry2Ab 毒素进行了比较，并确定了它们之间的系统发育关系。Cry2Ab25 蛋白的推导氨基酸序列与已知的 Cry2Ab 蛋白具有 99%的同源性，除了与 Cry2Ab10 和 Cry2Ab12 具有 97%的同源性外，与所有已知的 Cry2Ab 蛋白相比，只有一个氨基酸残基发生了变化。cry2Ab25 基因在大肠杆菌 BL21(DE3)细胞中表达。十二烷基硫酸钠-聚丙烯酰胺凝胶电泳 (SDS-PAGE) 显示 Cry2Ab25 蛋白约为 70kDa。在 BL21(DE3)中表达的毒素对舞毒蛾和樱桃红尾天蛾表现出很高的毒性，处理 5 天后死亡率分别为 73%和 75%。
