从鳗弧菌M3 Fosmid文库筛选aroA基因

Screening aroA gene from the Vibrio anguillarum Fosmid library

为克隆鳗弧菌 aroA 基因(它在细菌中编码合成芳香族氨基酸的关键酶——5-烯醇氏丙酮酰莽草酸3-磷酸(EPSP)合成酶),在实验室中构建了鳗弧菌 M3大分子量基因组Fosmid 文库,并通过克隆测序获得了部分序列,以此为基础,通过延伸测序获得了 aroA 基因序列全长。该基因全长1281bp,编码427个氨基酸,包含一个11个氨基酸残基的信号肽;编码区 GC 平均含量为46.8%,推测分子量为46177 Da。相似性分析表明,鳗弧菌的aroA 核苷酸和氨基酸序列与其他弧菌的相似性最高,分别在73%～75%和78%～82%;进化树结果也表明鳗弧菌 aroA 与其他弧菌的亲缘关系最近。aroA 基因的克隆为构建鳗弧菌弱毒疫苗奠定了基础。

The aroA gene of Vibrio anguillarum, which encodes 5-enolpyruvylshikimate 3-phosphate （EPSP） synthase, was cloned and sequenced from the Fosmid library of Vibrio anguillarum M3 strain. The full-length sequence of the aroA consists of 1281bp, encoding for 427 amino acids with a calculated molecular mass of 46177 dahons, and its GC content is 46.8 %. The aroA contains a putative signal peptide of 11 amino acid residues. The similarity analysis indicated the aroA of V. anguillarum has high nucleotide and amino acid sequence homology with those of other bacteria, with the identities of 73%-75% and 78%-82%, and phylogenetic analyse showed it has a close relationship with the other bacteria of Vibiro sp. The present result opens a window to access to the study of attenuated live vaccines of V. anguillarum.