烟粉虱内共生菌传毒相关groEL基因的克隆及其原核表达

Cloning and prokaryotic expression of a viral binding protein gene (groEL) from endosymbionts in Bemisia tabaci

烟粉虱内共生菌 groEL基因编码一种 6 3kD的GroEL蛋白 ,利用一对特异性引物 ,通过PCR对长期培养在黄瓜上的烟粉虱体内 groEL基因进行了扩增 ,序列测定表明其长度为 16 6 8bp ,编码 5 5 5个氨基酸 ,与GenBank中烟粉虱内共生菌 groEL(AF130 4 2 1)的核苷酸同源性为 99.5 8%,仅 7个核苷酸发生了变异 ,二者氨基酸序列同源性为 99.2 8%,仅 4个氨基酸有别。构建了一个原核表达载体 ,表达得到了

GroEL, a 63 kD viral binding protein encoded by groEL gene from endosymbionts in Bemisia tabaci, plays an important role in transmission of plant viruses. A groEL gene from endosymbionts in B. tabaci on cucumber was amplified by PCR method and sequenced. The nucleotide sequence indicated that groEL had 1 668 bp nucleotides and encoded 555 amino acids. This gene had 99.58% similarity on nucleotides level and 99.28% similarity on amino acid level to AF130421, a groEL gene from endosymbionts in B. tabaci in GenBank. There were only 7 variation sites in nucleotides and 4 variation sites in amino acids. SDS-PAGE showed a clear 76 kD fusion protein when the groEL gene was inserted into Pinpoint^(TM) Xa-1 T vector and expressed in E.coli JM109.