首页> 外文期刊>Journal of Molecular Biology >The crystal structure of murine CMP-5-N-acetylneuraminic acid synthetase.
【24h】

The crystal structure of murine CMP-5-N-acetylneuraminic acid synthetase.

机译:鼠类CMP-5-N-乙酰神经氨酸合成酶的晶体结构。

获取原文
获取原文并翻译 | 示例
           

摘要

Sialic acids are activated by CMP-5-N-acetylneuraminic acid synthetase prior to their transfer onto oligo- or polysaccharides. Here, we present the crystal structure of the N-terminal catalytically active domain of the murine 5-N-acetylneuraminic acid synthetase in complex with the reaction product. In contrast to the previously solved structure of 5-N-acetylneuraminic acid synthetase from Neisseria meningitidis and the related CMP-KDO-synthetase of Escherichia coli, the murine enzyme is a tetramer, which was observed with the active sites closed. In this conformation a loop is shifted by 6A towards the active site and thus an essential arginine residue can participate in catalysis. Furthermore, a network of intermolecular salt-bridges and hydrogen bonds in the dimer as well as hydrophobic interfaces between two dimers indicate a cooperative behaviour of the enzyme. In addition, a complex regulation of the enzyme activity is proposed that includes phosphorylation and dephosphorylation.
机译:唾液酸在转移到寡糖或多糖上之前,先用CMP-5-N-乙酰神经氨酸合成酶激活。在这里,我们提出与反应产物配合的鼠5-N-乙酰神经氨酸合成酶的N末端催化活性域的晶体结构。与先前从脑膜炎奈瑟氏球菌得到的5-N-乙酰神经氨酸合成酶和大肠杆菌的相关CMP-KDO-合成酶的结构相反,鼠类酶是四聚体,观察到活性位点关闭。在这种构象中,环向着活性位点移动了6A,因此必需的精氨酸残基可以参与催化。此外,二聚体中分子间盐桥和氢键的网络以及两个二聚体之间的疏水性界面表明该酶的协同行为。另外,提出了对酶活性的复杂调节,包括磷酸化和去磷酸化。

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