上海交通大学学报(医学版)

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长双歧杆菌染色体上的基因BLJ_864和BLJ_865构成的Ⅱ型毒素—抗毒素系统

韦艳霞1,2,叶 露2,刘佃滨3,郭晓奎2   

  1. 1.徐州医学院病原生物学与免疫学教研室, 徐州 221004; 2.上海交通大学 基础医学院病原生物学教研室, 上海 200025; 3.徐州医学院 口腔医学院, 徐州 221004
  • 出版日期:2014-09-28 发布日期:2014-09-26
  • 通讯作者: 郭晓奎, 电子信箱: microbiology@sjtu.edu.cn。
  • 作者简介:韦艳霞(1984—), 女, 讲师, 博士; 电子信箱: weiyx2007@aliyun.com。
  • 基金资助:

    国家自然科学基金(31300029);江苏省自然科学基金(BK20130213);江苏省高校“青蓝工程”优秀青年骨干教师项目;徐州医学院优秀人才科研启动基金(D2012014)

A typeⅡ toxin-antitoxin system encoded by BLJ_864 and BLJ_865 in chromosome of Bifidobacterium longum

WEI Yan-xia1,2, YE Lu2, LIU Dian-bin3, GUO Xiao-kui2   

  1. 1.Department of Pathogenic Biology and Immunology, Xuzhou Medical College, Xuzhou 221004, China; 2.Department of Microbiology and Immunity, Basic Medicine Faculty, Shanghai Jiao Tong University, Shanghai 200025, China; 3.School of Stomatology, Xuzhou Medical College, Xuzhou 221004, China
  • Online:2014-09-28 Published:2014-09-26
  • Supported by:

    National Natural Science Foundation of China, 31300029;Natural Science Foundation of Jiangsu Province, China, BK20130213; Qing Lan Project for Excellent Young Teachers in Higher Education of Jiangsu; Scientific Research Foundation for Talents of Xuzhou Medical College, D2012014

摘要:

目的 鉴定Bifidobacterium longum JDM301 (B.longum JDM301)染色体上的BLJ_864、BLJ_865是否构成mazEF家族的一组Ⅱ型毒素—抗毒素系统(TA系统)。方法 通过RT-PCR分析BLJ_864和BLJ_865在B.longum JDM301以及E.coli中的共转录;通过将带有BLJ_864和BLJ_865的完整操纵子的质粒转化入E. coli,证明同一操纵子中的BLJ_864、BLJ_865所编码的抗毒素蛋白和毒素蛋白共表达;通过在E.coli中单独表达BLJ_864编码的毒素蛋白或将其与BLJ_865编码的抗毒素蛋白共表达,鉴定BLJ_864编码的毒素蛋白对细菌生长的抑制作用及其对应的BLJ_865编码的抗毒素蛋白能否消除毒素蛋白的生长抑制作用。结果 BLJ_864和BLJ_865构成一个二元操纵子,两者在其天然菌株B.longum JDM301中可以共转录;异丙基-β-D 硫代半乳糖苷(IPTG)诱导下,BLJ_864和BLJ_865所编码的抗毒素蛋白和毒素蛋白在异源宿主E. coli中共表达。BLJ_864编码的毒素蛋白的表达抑制异源宿主E.coli的生长,而将BLJ_865所编码的抗毒素蛋白与BLJ_864编码的毒素蛋白共表达则可以拮抗毒素蛋白的生长抑制作用。结论 B.longum JDM301基因组中的假定基因BLJ_864和BLJ_865编码一组有功能的、隶属mazEF家族的Ⅱ型TA系统。

关键词: 毒素—抗毒素系统, 长双歧杆菌, mazEF

Abstract:

Objective To identify whether the BLJ_864 and BLJ_865 in the chromosome of Bifidobacterium longum JDM301 (B.longum JDM301) constitute a type II toxinantitoxin system (TA system) of mazEF family. Methods The co-transcription of BLJ_864 and BLJ_865 in B.longum JDM301 and E.coli was analyzed by the RT-PCR. The co-expression of BLJ_864 and BLJ_865 encoded antitoxin protein and toxin protein in the intact operon that carried BLJ_864 and BLJ_865 was proved by transforming the plasmid, which carried the operon, into the E.coli strain. The inhibition effect of BLJ_864 encoded toxin protein on the growth of E.coli cells and the corresponding effect of BLJ_865 encoded antitoxin protein on removing the inhibition effect were identified by the expression of BLJ_864 encoded toxin protein or co-expression of the toxin protein and BLJ_865 encoded antitoxin protein in E.coli. Results BLJ_864 and BLJ_865 constituted a dual operon and could co-transcript in the natural strain of B.longum JDM301. BLJ_864 encoded toxin protein and BLJ_865 encoded antitoxin protein could co-express in the heterologous host of E.coli when induced by isopropyl-β-D-thiogalactopyranoside (IPTG). The expression of BLJ_864 encoded toxin protein inhibited the growth of E.coli, while the co-expression of BLJ_864 encoded toxin protein and BLJ_865 encoded antitoxin protein could antagonize the inhibition effect of toxin protein. Conclusion BLJ_864 and BLJ_865 in the chromosome of B.longum JDM301 encode a functional type II TA system of mazEF family.

Key words: toxin-antitoxin system, Bifidobacterium longum, mazEF