Wasano Naoya, Saitoh Hiroyuki, Maeda Minoru, Ohgushi Akira, Mizuki Eiichi, Ohba Michio
Biotechnology and Food Research Institute, Fukuoka Industrial Technology Center, Kurume 839-0861, Japan.
Can J Microbiol. 2005 Nov;51(11):988-95. doi: 10.1139/w05-084.
A novel delta-endotoxin gene from a lepidopteran-specific Bacillus thuringiensis serovar galleriae strain was cloned, and the full sequence of the cry gene was determined. The cloned 6.5-kb DNA fragment included the full sequence of the cry gene and three open reading frames located upstream of the cry gene. The gene, designated cry9Ec1, encodes a polypeptide of 1154 amino acid residues with a predicted molecular weight of 130 237. The deduced amino acid sequence of the Cry9Ec1 protein had the highest homology (77.7%) with the Cry9Ea1 protein when compared with existing Cry proteins. The expression, in an acrystalliferous B. thuringiensis strain, of the cry9Ec1 gene was high when controlled by the cyt1A2 promoter, leading to the formation of large spherical inclusions. The purified crystals from the recombinant strain were toxic when tested against two lepidopteran species, Bombyx mori and Plutella xylostella. However, the Cry9Ec1 protein gave no toxicity against Spodoptera litura, Spodoptera exigua, Plodia interpunctella, Helicoverpa zea, and Culex pipiens molestus.
克隆了来自一种鳞翅目特异性苏云金芽孢杆菌蜡螟亚种菌株的新型δ-内毒素基因，并测定了cry基因的完整序列。克隆的6.5 kb DNA片段包含cry基因的完整序列以及位于cry基因上游的三个开放阅读框。该基因命名为cry9Ec1，编码一个由1154个氨基酸残基组成的多肽，预测分子量为130237。与现有Cry蛋白相比，Cry9Ec1蛋白的推导氨基酸序列与Cry9Ea1蛋白具有最高的同源性（77.7%）。当由cyt1A2启动子控制时，cry9Ec1基因在无晶体的苏云金芽孢杆菌菌株中表达量很高，导致形成大的球形包涵体。重组菌株纯化后的晶体对两种鳞翅目昆虫家蚕和小菜蛾进行测试时具有毒性。然而，Cry9Ec1蛋白对斜纹夜蛾、甜菜夜蛾、印度谷螟、棉铃虫和骚扰库蚊没有毒性。
