...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>The FEBS journal >The role of residue Thr249 in modulating the catalytic efficiency and substrate specificity of catechol-2,3-dioxygenase from Pseudomonas stutzeri OX1
【24h】

The role of residue Thr249 in modulating the catalytic efficiency and substrate specificity of catechol-2,3-dioxygenase from Pseudomonas stutzeri OX1

机译：Thr249残基在调节斯氏假单胞菌OX1中邻苯二酚-2,3-双加氧酶的催化效率和底物特异性中的作用

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

Bioremediation strategies use microorganisms to remove hazardous substances, such as aromatic molecules, from polluted sites. The applicability of these techniques would greatly benefit from the expansion of the catabolic ability of these bacteria in transforming a variety of aromatic compounds. Catechol-2,3-dioxygenase (C2,3O) from Pseudomonas stutzeri OX1 is a key enzyme in the catabolic pathway for aromatic molecules. Its specificity and regioselectivity control the range of molecules degraded through the catabolic pathway of the microorganism that is able to use aromatic hydrocarbons as growth substrates. We have used in silico substrate docking procedures to investigate the molecular determinants that direct the enzyme substrate specificity. In particular, we looked for a possible molecular explanation of the inability of catechol-2,3-dioxygenase to cleave 3,5-dimethylcatechol and 3,6-dimethylcatechol and of the efficient cleavage of 3,4-dimethylcatechol. The docking study suggested that reduction in the volume of the side chain of residue 249 could allow the binding of 3,5-dimethylcatechol and 3,6-dimethylcatechol. This information was used to prepare and characterize mutants at position 249. The kinetic and regiospecificity parameters of the mutants confirm the docking predictions, and indicate that this position controls the substrate specificity of catechol-2,3-dioxygenase. Moreover, our results suggest that Thr249 also plays a previously unsuspected role in the catalytic mechanism of substrate cleavage. The hypothesis is advanced that a water molecule bound between one of the hydroxyl groups of the substrate and the side chain of Thr249 favors the deprotonation/protonation of this hydroxyl group, thus assisting the final steps of the cleavage reaction.
机译：生物修复策略使用微生物从污染部位去除有害物质，例如芳香分子。这些技术的应用将极大地受益于这些细菌在转化各种芳香化合物中的分解代谢能力的扩展。来自斯氏假单胞菌OX1的儿茶酚-2,3-二加氧酶（C2,3O）是芳香族分子分解代谢途径中的关键酶。它的特异性和区域选择性控制了通过微生物分解代谢途径降解的分子的范围，该微生物能够使用芳香烃作为生长底物。我们已经在计算机模拟底物对接程序中研究了指导酶底物特异性的分子决定因素。尤其是，我们寻找一种可能的分子解释，说明儿茶酚-2,3-二加氧酶不能裂解3,5-二甲基邻苯二酚和3,6-二甲基邻苯二酚，以及有效裂解3,4-二甲基邻苯二酚。对接研究表明，残基249的侧链体积的减少可以使3，5-二甲基邻苯二酚和3，6-二甲基邻苯二酚结合。该信息用于制备和表征249位突变体。突变体的动力学和区域特异性参数证实了对接预测，并表明该位置控制了邻苯二酚-2,3-双加氧酶的底物特异性。此外，我们的结果表明，Thr249在底物裂解的催化机制中也发挥了之前未曾想到的作用。提出了假说，即结合在底物的羟基之一和Thr249侧链之间的水分子有利于该羟基的去质子化/质子化，从而有助于裂解反应的最后步骤。

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