中国媒介生物学及控制杂志 ›› 2011, Vol. 22 ›› Issue (3): 251-256.

• 论著 • 上一篇    下一篇

鼠疫菌、副溶血性弧菌及肺炎克雷伯菌CRP蛋白的表达及其DNA结合活性分析

杨琳1,2, 高鹤2,3, 张义全2, 刘霞1,2, 谭亚芳2, 郭兆彪2, 黄新祥1, 杨瑞馥2, 周冬生2   

  1. 1 江苏大学生命科学研究院,江苏 镇江 212013;
    2 军事医学科学院微生物流行病研究所,病原微生物生物安全国家重点实验室,北京 100071;
    3 中国疾病预防控制中心传染病预防控制所,传染病预防控制国家重点实验室,北京 102206
  • 收稿日期:2011-02-12 出版日期:2011-06-20 发布日期:2011-06-20
  • 通讯作者: 高鹤,Email: gaohe@yahoo.cn; 周冬生,Email: dongshengzhou1977@gmail.com
  • 作者简介:杨琳(1984-),女,硕士研究生,从事病原菌转录调控机制研究。Email: leonkoala@126.com
  • 基金资助:

    国家自然科学基金(30930001,30900823,30771179); 973项目(2009CB522600)

Expression and DNA-binding activity of the cyclic AMP receptor proteins in Yersinia pestis, Vibrio parahaemolyticus and Klebsiella pneumoniae

YANG Lin1,2, GAO He2,3, ZHANG Yi-quan2, LIU Xia1,2, TAN Ya-fang2, GUO Zhao-biao2, HUANG Xin-xiang1, YANG Rui-fu2, ZHOU Dong-sheng2   

  1. 1 Institute of Life Science, Jiangsu University, Zhenjiang 212013, Jiangsu Province, China;
    2 State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China;
    3 State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
  • Received:2011-02-12 Online:2011-06-20 Published:2011-06-20
  • Supported by:

    Supported by the National Natural Science Foundation of China (No. 30930001,30900823, 30771179) and Program 973 (No. 2009CB522600)

摘要:

目的 表达有活性的鼠疫耶尔森菌(鼠疫菌)、副溶血性弧菌以及肺炎克雷伯菌的cAMP受体蛋白(CRP)并进行DNA体外结合活性分析,为深入研究3种CRP蛋白间的交互转录调控作用奠定基础。方法 应用大肠埃希菌pET系统体外表达鼠疫菌201株、副溶血性弧菌5421株以及肺炎克雷伯菌tw518株的CRP蛋白;应用生物信息学对3种CRP蛋白进行同源性比较,并对CRP与靶DNA的结合基序(CRP consensus)进行分析预测;通过体外凝胶阻滞实验(EMSA)和DNaseⅠ足迹实验验证His-CRP与DNA的结合活性。结果 成功表达出3种菌有活性的His-CRP融合蛋白,3种CRP蛋白对鼠疫菌pla、副溶血性弧菌toxR及肺炎克雷伯菌kfuA基因均有结合活性。结论 3种CRP蛋白都能直接结合到鼠疫菌pla、副溶血性弧菌toxR及肺炎克雷伯菌kfuA基因的启动子区,说明上述3种CRP蛋白对3种病原菌的重要毒力基因的转录可能具有交互调控作用。

关键词: 鼠疫菌, 副溶血性弧菌, 肺炎克雷伯菌, cAMP受体蛋白, 交互调控

Abstract:

Objective To determine expression and DNA-binding activity of the recombinant CRP (cyclic AMP receptor protein) in Yersinia pestis, Vibrio parahaemolyticus and Klebsiella pneumoniae for the study of transcriptional interregulation. Methods The coding region of the crp gene of Y. pestis, V. parahaemolyticus and K. pneumoniae was amplified by PCR, and cloned into the BamHⅠ and Hind Ⅲ sites of a pET28a vector. The recombinant plasmid pET28a-crp was inducted into BL21λDE3. Over-expression of His-CRP in the LB medium was induced by adding 1 mmol/L IPTG (isopropyl-b-D-thiogalactoside). The over-expressed protein was purified under native conditions with nickel loaded HiTrap Chelating Sepharose columns (Amersham). Electrophoretic mobility shift assay (EMSA) and DNase I footprinting experiments were carried out to analyze the DNA-binding activity of the three CRP proteins in vitro. Results All three purified His-CRP proteins were able to bind to the upstream DNA regions of Y. pestis (psaA), V. parahaemolyticus (toxR), and K. pneumoniae (kfuA). Conclusion Recombinant CRP proteins of Y. pestis, V. parahaemolyticus and K. pneumoniae were expressed and purified, suggesting their inter-regulatory effect on the transcription of key virulence genes of the three pathogens.

Key words: Yersinia pestis, Vibrio parahaemolyticus, Klebsiella pneumoniae, Cyclic AMP receptor proteins, Inter-regulation

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