Yamamoto T, Watkinson I A, Kim L, Sage M V, Stratton R, Akande N, Li Y, Ma D P, Roe B A
Agricultural Products Department, DuPont Company, Wilmington, DE 19898.
Gene. 1988 Jun 15;66(1):107-20. doi: 10.1016/0378-1119(88)90229-6.
The nucleotide sequence of pVB131 containing the gene coding for a 130-kDa Bacillus thuringiensis israelensis (B.t.isr) mosquitocidal protein was determined. The pVB131 plasmid was constructed by Sekar and Carlton [Gene 33 (1985) 151-158]. Our sequencing revealed only one open reading frame large enough to code for a protein of 130 kDa. The translation start site was determined by sequencing the protein isolated from B.t.isr. The amino acid sequence of the protein was deduced from the nucleotide sequence, and its Mr was determined as 128,505. Immunological and biochemical analyses of B.t.isr mosquitocidal proteins indicated that the 130-kDa protein coded by pVB131 was indeed expressed in B.t.isr. Comparing the peptide sequence of the 130-kDa B.t.isr toxin with the sequences of other B.t. toxins having activities specific to lepidopteran species showed that several domains were highly homologous. This suggests that they are evolutionarily related to each other, and in the evolutionary process the sequences in the homologous domains that are important to the insecticidal activity have been conserved.
测定了含有编码130 kDa苏云金芽孢杆菌以色列亚种（B.t.isr）杀蚊蛋白基因的pVB131的核苷酸序列。pVB131质粒由Sekar和Carlton构建[《基因》33（1985年）151 - 158页]。我们的测序结果显示只有一个足够大的开放阅读框能够编码130 kDa的蛋白质。通过对从B.t.isr分离的蛋白质进行测序确定了翻译起始位点。根据核苷酸序列推导该蛋白质的氨基酸序列，其分子量确定为128,505。对B.t.isr杀蚊蛋白的免疫学和生化分析表明，pVB131编码的130 kDa蛋白质确实在B.t.isr中表达。将130 kDa B.t.isr毒素的肽序列与其他对鳞翅目物种具有特异性活性的B.t.毒素的序列进行比较，结果显示几个结构域高度同源。这表明它们在进化上相互关联，并且在进化过程中，对杀虫活性重要的同源结构域中的序列得以保留。
