Rang Cécile, Gil Patricia, Neisner Nathalie, Van Rie Jeroen, Frutos Roger
Cirad, TA 30/D, Campus International de Baillarguet, 34398 Montpellier Cedex 5, France.
Appl Environ Microbiol. 2005 Oct;71(10):6276-81. doi: 10.1128/AEM.71.10.6276-6281.2005.
A novel vip3-related gene was identified in Bacillus thuringiensis. This novel gene is 2,406 bp long and codes for a 91-kDa protein (801 amino acids). This novel protein exhibits between 61 and 62% similarity with Vip3A proteins and is designated Vip3Ba1. Vip3Ba1 has several specific features. Differences between Vip3Ba1 and the Vip3A proteins are spread throughout the sequence but are more frequent in the C-terminal part from amino acid 456 onward. The regions containing the two proteolytic processing sites, which are highly conserved among the Vip3A toxins, are markedly different in Vip3Ba1. The pattern DCCEE (Asp Cys Cys Glu Glu) is repeated four times between position 463 and 483 in Vip3Ba1, generating the sequence 463-DCCEEDCCEEDCCEEDCCEE-483. This sequence, which is rich in negatively charged amino acids, also contains 73% of the cysteines present in Vip3Ba1. This repeated sequence is not present in Vip3A proteins. The Vip3Ba1protein was produced in Escherichia coli and tested against Ostrinia nubilalis and Plutella xylostella, and it generated significant growth delays but had no larvicidal effect, indicating that its host range might be different than that of Vip3A proteins.
在苏云金芽孢杆菌中鉴定出一个与vip3相关的新基因。这个新基因长度为2406 bp，编码一种91 kDa的蛋白质（801个氨基酸）。这种新蛋白质与Vip3A蛋白质具有61%至62%的相似性，被命名为Vip3Ba1。Vip3Ba1具有几个特定特征。Vip3Ba1与Vip3A蛋白质之间的差异遍布整个序列，但在从第456位氨基酸开始的C末端部分更为频繁。在Vip3A毒素中高度保守的包含两个蛋白水解加工位点的区域，在Vip3Ba1中明显不同。模式DCCEE（天冬氨酸-半胱氨酸-半胱氨酸-谷氨酸-谷氨酸）在Vip3Ba1的第463位和483位之间重复出现四次，产生序列463-DCCEEDCCEEDCCEEDCCEE-483。这个富含带负电荷氨基酸的序列，也包含了Vip3Ba1中73%的半胱氨酸。这种重复序列在Vip3A蛋白质中不存在。Vip3Ba1蛋白在大肠杆菌中产生，并针对欧洲玉米螟和小菜蛾进行了测试，它导致了显著的生长延迟，但没有杀幼虫效果，这表明它的宿主范围可能与Vip3A蛋白质不同。
