...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Biochemistry >Sensation and Signaling of α-Ketoglutarate and Adenylylate Energy Charge by the Escherichia coli PII Signal Transduction Protein Require Cooperation of the Three Ligand-Binding Sites within the PII Trimer
【24h】

Sensation and Signaling of α-Ketoglutarate and Adenylylate Energy Charge by the Escherichia coli PII Signal Transduction Protein Require Cooperation of the Three Ligand-Binding Sites within the PII Trimer

机译：大肠杆菌PII信号转导蛋白对α-酮戊二酸和腺苷酸能量电荷的感知和信号传递需要PII三聚体中三个配体结合位点的协同作用

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

PII proteins are sensors of R-ketoglutarate and adenylylate energy charge that regulate signalntransduction proteins, metabolic enzymes, and permeases involved in nitrogen assimilation. Here, purifiednEscherichia coli PII and two of its receptors,ATase andNRII, were used to study themechanisms of sensationnby PII. We assembled heterotrimeric forms of PII from wild-type and mutant subunits, which allowed us tonassess the role of the three binding sites for R-ketoglutarate and adenylylate nucleotide in the PII trimer.nSignaling of R-ketoglutarate and adenylylate energy charge by these heterotrimeric PII proteins requirednmultiple binding sites for these effectors, and the ligand-binding sites on different subunits could influence thenfunction of a single subunit interacting with a receptor, implying communication between PII subunits.Wild-ntype and heterotrimeric forms of PII were also used to examine the effects of R-ketoglutarate and ADP on PIInactivation of the adenylyltransferase (AT) activity of ATase. Previous work showed that when ATP was thensole adenylylate nucleotide, R-ketoglutarate controlled the extent of PII activation but did not alter the PIInactivation constant (Kact). We show that ADP affected both the PII Kact and the extent of activation by PII.nWhen ATP was present, ADP dramatically reduced the Kact for wild-type PII, and this effect was antagonizednby R-ketoglutarate. Consequently, whenATP was present, the antagonismbetweenADP and R-ketoglutaratenallowed each of these effectors to influence the PII Kact for activation of ATase. A study of heterotrimericnforms of PII suggested that the major part of the ability of ADP to improve the binding of PII to ATasenrequired multiple nucleotide binding sites and intersubunit communication.We also used nondenaturing gelnelectrophoresis to investigate the effect ofADP and R-ketoglutarate on the binding of PII toATase andNRII.nThese studies showed that ATase and NRII differ in their requirements for interaction with PII, and thatnunder the appropriate conditions, the antagonism between R-ketoglutarate and ADP allowed each of theseneffectors to influence the binding of PII to receptors.
机译：PII蛋白是R-酮戊二酸和腺苷酸能电荷的传感器，可调节信号转导蛋白，代谢酶和参与氮同化的通透酶。在这里，纯化的大肠杆菌PII及其两个受体，ATase和NRII被用来研究PII引起的感觉机制。我们从野生型和突变型亚基组装了PII的异三聚体形式，这使我们可以忽略RII的三个结合位点在PII三聚体中的作用。n这些异三聚体PII信号化R-酮戊二酸和腺苷酸的能量电荷蛋白质需要这些效应子的多个结合位点，并且不同亚基上的配体结合位点可能会影响单个亚基与受体相互作用的功能，这意味着PII亚基之间的交流.PII的野生型和异源三聚体形式也用于检验其作用酮戊二酸和ADP对PIase的腺苷酸转移酶（AT）活性的灭活作用。先前的工作表明，当ATP是唯一的腺苷酸核苷酸时，R-酮戊二酸控制PII活化的程度，但不改变PIInactivation常数（Kact）。我们表明，ADP影响PII Kact和PII激活的程度。n当存在ATP时，ADP大大降低了野生型PII的Kact，并且这种作用被R-酮戊二酸拮抗。因此，当存在ATP时，ADP和R-酮戊二烯基戊糖之间的拮抗作用使这些效应子各自影响PII Kact以激活ATase。对PII异三聚体的研究表明，ADP改善PII与ATasen结合的能力的主要部分需要多个核苷酸结合位点和亚基间的通讯。我们还使用非变性凝胶电泳研究了ADP和R-酮戊二酸对ATasen结合的影响。这些研究表明，ATase和NRII在与PII相互作用方面的要求不同，并且在适当的条件下，R-酮戊二酸与ADP之间的拮抗作用使每种增效剂均能影响PII与受体的结合。

著录项

  • 来源
    《Biochemistry》 |2009年第48期|p.11522-11531|共10页
  • 作者

    Peng Jiang and Alexander J. Ninfa;

  • 作者单位

    Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan 48109-0606;

  • 收录信息
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号