• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Proceedings of the National Academy of Sciences of the United States of America >X-ray structure of a bifunctional protein kinase in complex with its protein substrate HPr
【24h】

X-ray structure of a bifunctional protein kinase in complex with its protein substrate HPr

机译：双功能蛋白激酶及其蛋白底物HPr的X射线结构

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

HPr kinase/phosphorylase (HprK/P) controls the phosphorylation state of the phosphocarrier protein HPr and regulates the utilization of carbon sources by Gram-positive bacteria. It catalyzes both the ATP-dependent phosphorylation of Ser-46 of HPr and its dephosphorylation by phosphorolysis. The latter reaction uses inorganic phosphate as substrate and produces pyrophosphate. We present here two crystal structures of a complex of the catalytic domain of Lactobacillus casei HprK/P with Bacillus subtilis HPr, both at 2.8-A resolution. One of the structures was obtained in the presence of excess pyrophosphate, reversing the phosphorolysis reaction and contains serine-phosphorylated HPr. The complex has six HPr molecules bound to the hexameric kinase. Two adjacent enzyme subunits are in contact with each HPr molecule, one through its active site and the other through its C-terminal helix. In the complex with serine-phosphorylated HPr, a phosphate ion is in a position to perform a nucleophilic attack on the phospho-serine. Although the mechanism of the phosphorylation reaction resembles that of eukaryotic protein kinases, the dephosphorylation by inorganic phosphate is unique to the HprK/P family of kinases. This study provides the structure of a protein kinase in complex with its protein substrate, giving insights into the chemistry of the phospho-transfer reactions in both directions.
机译：HPr激酶/磷酸化酶（HprK / P）控制磷酸载体蛋白HPr的磷酸化状态，并调节革兰氏阳性细菌对碳源的利用。它既能催化HPr的Ser-46的ATP依赖磷酸化，又能通过磷解作用使其脱磷酸化。后一反应使用无机磷酸盐作为底物并产生焦磷酸盐。我们在此介绍了干酪乳杆菌HprK / P与枯草芽孢杆菌HPr的催化结构域的复合物的两个晶体结构，均为2.8-A分辨率。在过量的焦磷酸盐的存在下获得了一种结构，该结构逆转了磷解反应并且包含丝氨酸磷酸化的HPr。该复合物具有结合至六聚体激酶的六个HPr分子。两个相邻的酶亚基与每个HPr分子接触，一个通过其活性位点，另一个通过其C末端螺旋线。在具有丝氨酸磷酸化的HPr的复合物中，磷酸根离子能够对磷酸丝氨酸进行亲核攻击。尽管磷酸化反应的机制类似于真核蛋白激酶，但无机磷酸的去磷酸化作用是激酶的HprK / P家族所独有的。这项研究提供了一种与蛋白底物复合的蛋白激酶结构，从而使人们对两个方向的磷酸转移反应的化学反应有了更深入的了解。

著录项

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