罗非鱼源无乳链球菌S-核糖基高半胱氨酸酶基因（luxS）的克隆及其推导蛋白的三维结构预测

Cloning of Streptococcus agalactiae luxS gene from tilapia and 3D structure prediction of deduced protein

摘要: 利用PCR技术对罗非鱼源无乳链球菌(Streptococcus agalactiae)S-核糖基高半胱氨酸酶（luxS）基因全长DNA进行了扩增、克隆和序列测定，采用ExPAsy软件包预测了推导蛋白的特性，利用Swiss-Model服务器建立了luxS 的三维结构，利用Swiss-PDBviewer软件进行了蛋白质三维结构的分析。预测结果显示，罗非鱼源无乳链球菌luxS推导蛋白包括保守的酶活性中心和锌结合位点，具有影响生物被膜形成、毒力因子调控等特性功能；经拉氏构象图（Ramachandran plot）分析，所构建的luxS的空间结构合理。

Abstract: We have amplified, cloned and determined the sequence of Streptococcus agalactiae luxS gene from Tilapia sp. by PCR. The characteristics of the deduced luxS protein were predicted by ExPAsy software; the 3D structures of luxS and the deduced protein were established and analyzed by SWISS-Model and Swiss-PDBviewer software, respectively. The results indicate that the deduced luxS protein contains conserved active center and Zn2+ binding site, which may affect biofilm formation and regulate virulence factor. The Ramachandram plot shows that the structure of modeled luxS protein is reasonable.