...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Biochemistry >Crystal structure of thiamin phosphate synthase from Bacillus subtilis at 1.25 A resolution.
【24h】

Crystal structure of thiamin phosphate synthase from Bacillus subtilis at 1.25 A resolution.

机译：枯草芽孢杆菌中硫胺素磷酸合酶的晶体结构，分辨率为1.25A。

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

The crystal structure of Bacillus subtilis thiamin phosphate synthase complexed with the reaction products thiamin phosphate and pyrophosphate has been determined by multiwavelength anomalous diffraction phasing techniques and refined to 1.25 A resolution. Thiamin phosphate synthase is an alpha/beta protein with a triosephosphate isomerase fold. The active site is in a pocket formed primarily by the loop regions, residues 59-67 (A loop, joining alpha3 and beta2), residues 109-114 (B loop, joining alpha5 and beta4), and residues 151-168 (C loop, joining alpha7 and beta6). The high-resolution structure of thiamin phosphate synthase complexed with its reaction products described here provides a detailed picture of the catalytically important interactions between the enzyme and the substrates. The structure and other mechanistic studies are consistent with a reaction mechanism involving the ionization of 4-amino-2-methyl-5-hydroxymethylpyrimidine pyrophosphate at the active site to give the pyrimidine carbocation. Trapping of the carbocation by the thiazole followed by product dissociation completes the reaction. The ionization step is catalyzed by orienting the C-O bond perpendicular to the plane of the pyrimidine, by hydrogen bonding between the C4' amino group and one of the terminal oxygen atoms of the pyrophosphate, and by extensive hydrogen bonding and electrostatic interactions between the pyrophosphate and the enzyme.
机译：已通过多波长异常衍射定相技术确定了枯草芽孢杆菌硫胺素磷酸合酶与反应产物硫胺素磷酸盐和焦磷酸盐的晶体结构，并将其提纯至1.25 A分辨率。硫胺素磷酸合酶是具有磷酸三糖异构酶折叠的α/β蛋白。活性位点位于主要由环区域，残基59-67（A环，连接alpha3和beta2），残基109-114（B环，连接alpha5和beta4）和残基151-168（C环）形成的口袋中，加入alpha7和beta6）。硫胺磷酸合酶的高分辨率结构及其反应产物在此描述，提供了该酶与底物之间重要的催化相互作用的详细图片。该结构和其他机理研究与反应机理一致，该反应机理涉及在活性位点将4-氨基-2-甲基-5-羟甲基嘧啶焦磷酸电离以产生嘧啶碳正离子化。噻唑捕获碳阳离子，然后产物解离完成反应。通过使CO键垂直于嘧啶平面取向，通过C4'氨基与焦磷酸盐的末端氧原子之一之间的氢键，以及焦磷酸盐与磷酸根之间的广泛的氢键和静电相互作用来催化电离步骤酶。

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