...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Molecular Biology >Structural analysis of the rate-limiting transition states in the folding of Im7 and Im9: similarities and differences in the folding of homologous proteins.
【24h】

Structural analysis of the rate-limiting transition states in the folding of Im7 and Im9: similarities and differences in the folding of homologous proteins.

机译：Im7和Im9折叠中限速过渡态的结构分析：同源蛋白折叠中的相似性和差异。

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 bacterial immunity proteins Im7 and Im9 fold with mechanisms of different kinetic complexity. Whilst Im9 folds in a two-state transition at pH 7.0 and 10 degrees C, Im7 populates an on-pathway intermediate under these conditions. In order to assess the role of sequence versus topology in the folding of these proteins, and to analyse the effect of populating an intermediate on the landscape for folding, we have determined the conformational properties of the rate-limiting transition state for Im9 folding/unfolding using Phi(F)-value analysis and have compared the results with similar data obtained previously for Im7. The data show that the rate-limiting transition states for Im9 and Im7 folding/unfolding are similar: both are compact (beta(T)=0.94 and 0.89, respectively) and contain three of the four native helices docked around a specific hydrophobic core. Significant differences are observed, however, in the magnitude of the Phi(F)-values obtained for the two proteins. Of the 20 residues studied in both proteins, ten have Phi(F)-values in Im7 that exceed those in Im9 by more than 0.2, and of these five differ by more than 0.4. The data suggest that the population of an intermediate in Im7 results in folding via a transition state ensemble that is conformationally restricted relative to that of Im9. The data are consistent with the view that topology is an important determinant of folding. Importantly, however, they also demonstrate that while the folding transition state may be conserved in homologous proteins that fold with two and three-state kinetics, the population of an intermediate can have a significant effect on the breadth of the transition state ensemble.
机译：细菌免疫蛋白Im7和Im9折叠具有不同动力学复杂性的机制。在pH 7.0和10摄氏度时，Im9处于两态过渡折叠状态，而在这些条件下，Im7填充了一个途中中间体。为了评估序列对拓扑结构在这些蛋白质折叠中的作用，并分析在折叠环境中填充中间体的影响，我们确定了Im9折叠/解折叠的限速过渡态的构象性质使用Phi（F）值分析，并将结果与​​先前为Im7获得的相似数据进行了比较。数据显示，Im9和Im7折叠/展开的速率限制过渡状态相似：两者都很紧凑（分别为β（T）= 0.94和0.89），并且包含四个围绕特定疏水性核心的天然螺旋中的三个。但是，观察到两种蛋白质获得的Phi（F）值的大小存在显着差异。在两种蛋白质中研究的20个残基中，有10个在Im7中的Phi（F）值比在Im9中的Phi（F）值高0.2以上，而这5个差异相差超过0.4。数据表明，Im7中的中间体种群通过相对于Im9构象受限制的过渡态集合而折叠。数据与拓扑是折叠的重要决定因素的观点一致。然而，重要的是，他们还证明，虽然折叠过渡态在以二态和三态动力学折叠的同源蛋白质中可能是保守的，但中间体的数量可能会对过渡态集合的广度产生重大影响。

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