...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Biochemistry >Crystal Structure at 1.8 A Resolution and Identification of Active Site Residues of Sulfolobus solfataricus Peptidyl-tRNA Hydrolase
【24h】

Crystal Structure at 1.8 A Resolution and Identification of Active Site Residues of Sulfolobus solfataricus Peptidyl-tRNA Hydrolase

机译：1.8 A的晶体结构解析和Sulfolobus solfataricus肽基-tRNA水解酶的活性位点残基的鉴定

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 3-D structure of the peptidyl-tRNA hydrolase from the archaea Sulfolobus solfataricus has been solved at 1.8 A resolution.Homologues of this enzyme are found in archaea and eucarya.Bacteria display a different type of peptidyl-tRNA hydrolase that is also encountered in eucarya.In solution,the S.solfataricus hydrolase behaves as a dimer.In agreement,the crystalline structure of this enzyme indicates the formation of a dimer.Each protomer is made of a mixed five-stranded beta-sheet surrounded by two groups of two alpha-helices.The dimer interface is mainly formed by van der Waals interactions between hydrophobic residues belonging to the two N-terminal alpha1 helices contributed by two protomers.Site-directed mutagenesis experiments were designed for probing the basis of specificity of the archaeal hydrolase.Among the strictly conserved residues within the archaeal/eucaryal peptidyl-tRNA hydrolase family,three residues,K18,D86,and T90,appear of utmost importance for activity.They are located in the N-part of alphal and in the beta3-beta4 loop.K18 and D86,which form a salt bridge,might play a role in the catalysis thanks to their acid and basic functions,whereas the OH group of T90 could act as a nucleophile.These observations clearly distinguish the active site of the archaeal/eucaryal hydrolases from that of the bacterial/eucaryal ones,where a histidine is believed to serve as the catalytic base.
机译：来自古细菌Sulfolobus solfataricus的肽基tRNA水解酶的3-D结构已在1.8 A的分辨率下得到解析，该酶的同系物存在于古细菌和真细菌中，细菌显示出另一种类型的肽基tRNA水解酶，这种肽也曾在古细菌中发现。在溶液中，S.solfataricus水解酶表现为二聚体。一致地，该酶的晶体结构表明形成了二聚体。每个protomer由混合的五链β-折叠制成，被两个两组包围二聚体界面主要由两个启动子贡献的属于两个N末端α1螺旋的疏水残基之间的范德华相互作用形成。设计了针对站点的诱变实验，以探索古细菌水解酶的特异性基础。在古细菌/真人肽基-tRNA水解酶家族中严格保守的残基中，三个残基，K18，D86和T90对活性至关重要。 K18和D86形成盐桥，由于它们的酸和碱性功能，它们可能在催化中起作用，而T90的OH基可以充当这些观察结果清楚地区分了古细菌/真核水解酶的活性位点与细菌/真核水解酶的活性位点，其中组氨酸被认为是催化碱基。

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