牛乳腺炎无乳链球菌菌毛岛屿PI-2a辅助蛋白AP2基因的克隆及序列分析

Cloning and sequencing of PI-2a pillus island auxiliary protein AP2 genev of bovine mastitis Streptococcus agalactiae

目的克隆牛乳腺炎无乳链球菌菌毛岛屿PI-2a辅助蛋白AP2基因,并进行序列分析。方法根据GenBank公布的牛源无乳链球菌菌毛岛屿PI-2a的AP2基因序列,使用生物信息学软件Primer5.0设计1对特异性引物,以内蒙古东部地区乳源无乳链球菌临床菌株总DNA为模板,扩增AP2基因片段。结果扩增的AP2基因经克隆测序,长度为699bp,其序列与GenBank上公布的牛源无乳链球菌菌毛岛屿PI-2a的AP2基因(EU930008)相似性为99.57%,编码233个氨基酸残基,有2个核苷酸出现突变,但是氨基酸序列没有发生改变,属于无意义突变。结论成功克隆出内蒙古东部地区牛乳腺炎无乳链球菌PI-2a菌毛岛屿AP2基因,为进一步研究AP2基因编码蛋白的抗原性奠定了基础。

Objective Cloning of bovine mastitis Streptococcus agalactiae PI-2a pilus island accessory protein gene AP2,and sequencing. Methods According to the published PI-2a pilus island AP2 accessory protein gene sequences of bovine S.agalactiae on GenBank.A pairs of specific primers was designed with bioinformatics software of Primer5.0,and amplification of AP2 gene sequences with the S.agalactiae total DNA as the template of the S.agalactiae clinical strains form the Eastern Inner Mongolia. Result The amplified AP2 gene sequences had length 699 bp and amplified 233 amino acid.This sequnce had 99.57% of similarity to AP2 gene sequences with the bovine S.agalactiae AP2gene（EU930008）published on GenBank and had two nucleotides varied.But amino acid sequences had no varied. Conclusion The result showed that successfully cloned the AP2 gene of the bovine mastitis S.agalactiae of the eastern part of Inner Mongolia of China,and laid the foundation for further study on the antigenicity of the AP2 gene coding protein.