相似穿孔线虫S型半胱氨酸蛋白酶基因克隆与序列分析

根据不同种类线虫编码半胱氨酸蛋白酶的保守序列及植物寄生性线虫的半胱氨酸蛋白酶氨基酸密码子的偏好设计简并引物,通过RACE技术,首次从相似穿孔线虫(Radopholus similis)中克隆得到一个编码S型半胱氨酸蛋白酶基因的cDNA全长,命名为Rs-CPS(GenBank登录号EU659125)。Rs-CPS基因全长为1112bp,编码314个氨基酸,分子量为34.69ku。分析结果显示:Rs-CPS氨基酸序列具有半胱氨酸蛋白酶家族典型的Cys-His-Asn三联体酶催化活性中心,而且N端有1个17个氨基酸残基组成的信号肽。

Molecular cloning and sequence analysis of cathepsin S-like cysteine proteinase genes of Radopholus similis

By using rapid amplification of cDNA ends (RACE) protocol and primers that were designed based on the motif sequence present in all cathepsin cysteine proteinases of nematodes,the first cathepsin S-like cysteine proteinase gene from Radopholus similis,named as Rs-CPS (GenBank accession number EU659125) was amplified,sequenced and analyzed. The full length of Rs-CPS is 1 112 bp,encoding a polypeptide of 314 amino acid residues with a predicted molecular mass of 34.69 ku. Rs-CPS shows high sequence homology with other cathepsin cysteine proteinases. The Cys-His-Asn residues that formed catalytic triad were high conservation. It was therefore identified as a member of the cysteine proteinase gene family. And there is a signal peptide of 17 amino acid residues in Rs-CPS.