Tan Furong, Zhu Jun, Tang Jie, Tang Xueming, Wang Shiquan, Zheng Aiping, Li Ping
Rice Research Institute, Sichuan Agricultural University, Yaan, China.
Curr Microbiol. 2009 Jun;58(6):654-9. doi: 10.1007/s00284-009-9386-y. Epub 2009 Mar 11.
Bacillus thuringiensis strain BtMC28 was isolated from the soil sample in China. Two novel crystal protein genes were found by using the PCR-RFLP method. Moreover, the full-length sequences of two novel genes were obtained by a single oligonucleotide nested (SON)-PCR upstream and downstream strategy. Sequence analysis revealed that one gene encoded a polypeptide of 673 amino acid residues with a molecular mass of 76.3 kDa, 38% identical to Cry10Aa, and the other encoded a polypeptide of 687 amino acid residues with a molecular mass of 77.1 kDa, 74% identical to Cry30Aa. These two novel crystal protein genes were designated as cry54Aa1 and cry30Fa1 by Bt Insecticidal Crystal Proteins Nomenclature Committee, respectively. The Cry54Aa1 and Cry30Fa1 proteins retained five conserved regions commonly found in the existing Cry proteins. Cry54Aa1 protein exhibited insecticidal activities against Laphygma exigua (Lepidoptera), Helicoverpa armigera (Lepidoptera), and Aedes aegypti (Diptera) when its encoding gene was expressed in an Escherichia coli host strain.
苏云金芽孢杆菌菌株BtMC28是从中国的土壤样本中分离得到的。通过PCR-RFLP方法发现了两个新的晶体蛋白基因。此外，利用单链寡核苷酸嵌套（SON）-PCR上下游策略获得了这两个新基因的全长序列。序列分析表明，一个基因编码一个由673个氨基酸残基组成的多肽，分子量为76.3 kDa，与Cry10Aa的同源性为38%；另一个基因编码一个由687个氨基酸残基组成的多肽，分子量为77.1 kDa，与Cry30Aa的同源性为74%。这两个新的晶体蛋白基因分别被苏云金芽孢杆菌杀虫晶体蛋白命名委员会命名为cry54Aa1和cry30Fa1。Cry54Aa1和Cry30Fa1蛋白保留了现有Cry蛋白中常见的五个保守区域。当Cry54Aa1蛋白的编码基因在大肠杆菌宿主菌株中表达时，它对甜菜夜蛾（鳞翅目）、棉铃虫（鳞翅目）和埃及伊蚊（双翅目）表现出杀虫活性。
