波谱学杂志 ›› 2016, Vol. 33 ›› Issue (1): 77-88.doi: 10.11938/cjmr20160107

• 研究论文 • 上一篇    下一篇

二价金属离子与YycFN相互作用的NMR研究

刘婷1,2, 刘买利1, 姜凌1   

  1. 1. 中国科学院生物磁共振重点实验室, 波谱与原子分子物理国家重点实验室, 武汉磁共振中心(中国科学院 武汉物理与数学研究所), 湖北 武汉 430071;
    2. 中国科学院大学, 北京 10049
  • 收稿日期:2015-03-30 修回日期:2016-01-22 出版日期:2016-03-05 发布日期:2016-03-05
  • 通讯作者: 姜凌,电话:027-87198493,E-mail:lingjiang@wipm.ac.cn. E-mail:lingjiang@wipm.ac.cn
  • 作者简介:刘婷(1989-),女,陕西榆林人,硕士研究生,分析化学专业.
  • 基金资助:

    国家自然科学基金资助项目(21173257).

Divalent Metal Ion Binding to the Response Regulator YycFN Studied by NMR Spectroscopy

LIU Ting1,2, LIU Mai-li1, JIANG Ling1   

  1. 1. Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan (Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences), Wuhan 430071, China;
    2. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2015-03-30 Revised:2016-01-22 Online:2016-03-05 Published:2016-03-05

摘要:

YycGF最早发现于枯草芽孢杆菌,是与细胞存活密切相关的双组分信号转导系统,存在于少量低鸟嘌呤和胞嘧啶(G+C)含量的革兰氏阳性菌中,包括金黄色葡萄球菌和肺炎链球菌等人类病原菌.在外界环境刺激下,胞膜上的组氨酸激酶YycG通过自身组氨酸磷酸化活化,将磷酸根转移至反应调节蛋白YycF的N端调节区(YycFN)使之磷酸化,调控下游基因表达,实现特定细胞应答反应.二价金属离子在双组分信号转导系统反应调节蛋白的磷酸化过程中起着非常关键的作用,但它们与YycFN相互作用的机制尚不清楚.该文利用液体核磁共振(NMR)方法研究了Ca2+、Mg2+两种离子与YycFN的相互作用,对详细的相互作用界面进行了分析,并计算了Ca2+、Mg2+与YycFN的解离常数(Kd).发现金属离子的关键作用位点是Asp9、Asp16和Asp53等残基,蛋白的整体构象也发生了一定变化,为阐明二价金属离子在反应调节蛋白信号转导过程中的作用机制提供了重要线索.

关键词: 核磁共振(NMR), 金属离子, 相互作用, YycFN

Abstract:

YycGF, originally identified in Bacillus subtilis, is recognized as a crucial two-component signal transduction system closely associated with cell viability. It is highly conserved in low G+C Gram-positive bacteria, including Staphylococcus aureus, Streptococcus pneumoniae and other human pathogens. The histidine kinase (HK) YycG senses extracellular or intracellular signals and phosphorylates its cognate response regulator (RR) YycF, which in turn recognizes sequence specific regions on the bacterial chromosome and regulates the expression of certain genes. The presence of a divalent metal ion is essential for phosphoryl group transfer. Here, we presented a metal ion binding study of the response regulator YycF (YycFN) from Bacillus subtilis using NMR spectroscopy. The metal ions Ca2+ and Mg2+ induced severe chemical shift changes in YycF backbone resonances, involving mainly the Asp9, Asp16 and Asp53 residues. Furthermore, the binding affinities of Ca2+ and Mg2+ with YycFN were compared. The results provide important clues for understanding the conformational change of YycFN upon metal ion binding before its phosphorylation.

Key words: NMR, metal ions, interaction, YycFN

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