野生型金黄色葡萄球菌肠毒素A基因的克隆与分析

Molecular cloning and analysis of enterotoxin gene from wild-type Staphylococcus aureus

根据A、B、C和D肠毒素基因的序列设计特异引物,采用聚合酶链式反应(PCR)方法对食品中的金黄色葡萄球菌进行检测和鉴定肠毒素基因型,并进一步克隆肠毒素基因。结果表明,待检食品中的金黄色葡萄球菌的肠毒素基因为A型,序列长为774bp,编码257个氨基酸残基,同其他肠毒素A高度相似,等电点为8.85,是一种膜结合蛋白,功能结构域和三位结构预测分析发现此蛋白含有肠毒素家族结构域和肠毒素C家族结构域。

A gene from food sample was identified and cloned by PCR method with special primers for A、B、C and D enterotoxin genes in the study.The results of bioinformatics analysis suggested that the gene was a member of A enterotoxin gene family and was 774 bp in length,encoding 257 amino acids,the deduced protein shared high homology with other enterotoxins from Genbank,the pI was 8.85,and anchored in the membrane after secreted from the cell.The second structure and 3D prediction analysis indicated that the deduced protein contained Stap-Strp-toxin superfamily and Stap-Strp-tox C superfamily which composed the function domains of Staphylococcus aureus.