上海交通大学学报（医学版）

上海交通大学学报（医学版）

• 论著（基础研究） • 上一篇    下一篇

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

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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