山羊奇异变形杆菌毒力因子zapA基因的克隆及蛋白结构预测

Cloning and Prediction of Protein Structure of Virulence Factors zapA Gene of Proteus mirabilis from Goat

为了研究山羊奇异变形杆菌毒力因子,克隆zapA基因和预测推导的蛋白结构.采用PCR方法,对山羊奇异变形杆菌zapA基因进行扩增、克隆及序列测定;利用生物信息学软件预测推导zapA蛋白的信号肽、跨膜区、二级结构及B细胞抗原表位.结果表明:zapA基因长为1 476bp,编码491个氨基酸,与参考株的核苷酸序列同源性为99.59%,氨基酸同源性为99.59%;zapA蛋白存在信号肽,无跨膜区,B细胞表位可能位于69-71,78-84,136-139,197-199,353-356,371-373和472-474氨基酸区域内或附近.该试验为奇异变形杆菌zapA蛋白的表达及基因工程疫苗的研制提供了理论基础.

To clone the zapA gene,an important virulence factor of Proteus mirabilis,and predict its deducted protein,the zapA gene was subjected to PCR amplification,molecular cloning and DNA sequencing,and the gene sequence was then applied to bioinformatics program to predict the signal peptide,transmembrane domain,secondary structure and B cell epitopes of its deducted protein.DNA sequence showed that the zapA gene is 1 476 bp in size,encoding 491 amino acid residues,and shares 99.59% homology with the reference strain in both nucleotide and its encoded amino acid sequence.The bioinformatic analysis supported the existence of signal peptide,denied the presence of transmembrane domain and predicted the B cell epitopes of zapA locating in or near amino acids 69-71,78-84,136-139,197-199,353-356,371-373 and 472-474.These results are supposed to provide a theoretical basis for the expression of ZapA and the development of genetic engineering vaccines.