• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Molecular Biology >Evolutionary Morphing of Tryptophan Synthase: Functional Mechanisms for the Enzymatic Channeling of Indole
【24h】

Evolutionary Morphing of Tryptophan Synthase: Functional Mechanisms for the Enzymatic Channeling of Indole

机译：色氨酸合成酶的进化形态：吲哚酶促窜漏功能机制

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

Tryptophan synthase (TrpS) is a heterotetrameric alpha beta beta alpha enzyme that exhibits complex substrate channeling and allosteric mechanisms and is a model system in enzymology. In this work, we characterize proposed early and late evolutionary states of TrpS and show that they have distinct quaternary structures caused by insertions-deletions of sequence segments (indels) in the beta-subunit. Remarkably, indole hydrophobic channels that connect alpha and beta active sites have re-emerged in both TrpS types, yet they follow different paths through the beta-subunit fold. Also, both TrpS geometries activate the alpha-subunit through the rearrangement of loops flanking the active site. Our results link evolutionary sequence changes in the enzyme subunits with channeling and allostery in the TrpS enzymes. The findings demonstrate that indels allow protein quaternary architectures to escape "minima" in the evolutionary landscape, thereby overcoming the conservational constraints imposed by existing functional interfaces and being free to morph into new mechanistic enzymes. (C) 2018 Elsevier Ltd. All rights reserved.
机译：色氨酸合酶（TRP形式）是的异四聚α，β的β阿尔法酶表现出复杂的衬底窜和变构机制，是在酶学的模型系统。在这项工作中，我们提出了定性的TRP早期和晚期的进化状态，并表明他们具有因在beta亚基序列片段（插入缺失）的插入，删除不同的四级结构。值得注意的是，吲哚疏水通道连接的α和β的活性位点具有再现出两者的TRP的类型，但它们遵循通过所述β-亚基倍不同的路径。此外，两个的TRP几何激活通过环路侧翼的活性位点的重排的α亚基。我们的研究结果在酶亚基链接进化序列的变化与所述的TRP酶窜和变构效应。的研究结果表明，插入缺失允许蛋白质四级架构逃脱在进化风景“最小值”，从而克服由现有的功能的接口和能够自由地变形为新机理的酶所施加的保护性限制。 （c）2018年elestvier有限公司保留所有权利。

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