Variation of molecular alignment as a means of resolving orientational ambiguities in protein structures from dipolar couplings
Variation of molecular alignment as a means of resolving orientational ambiguities in protein structures from dipolar couplings
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DOI：
10.1006/jmre.2000.2049
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发表时间：
2000-04-01
影响因子：
2.2
通讯作者：
Prestegard, JH
中科院分区：
文献类型：
--
作者：
Al-Hashimi, HM;Valafar, H;Prestegard, JH
当分子溶解在稀液晶介质中时，可以使用高分辨率核磁共振方法轻松测量大分子中邻近磁核对的残余偶极耦合。产生的耦合原则上可用于约束大分子系统中分子片段的相对方向，以构建完整的结构。然而，基于一组残余偶极耦合来确定相对片段方向本质上受到偶极相互作用的角度依赖性的多值性质的阻碍。即使有无限的偶极数据，这也会导致片段方向的四倍简并。在本次通信中，我们演示了一种基于阶次张量分析的程序，该程序通过组合来自两种对准介质的残余偶极耦合测量来完全消除这种简并性。应用程序通过 N-15-H-1 残余偶极耦合数据得到证明，该数据是从溶解在两种不同 bicelle 介质中的巴氏梭菌的蛋白质锌红氧还蛋白上获得的。 (C) 2000 年学术出版社。
Residual dipolar couplings for pairs of proximate magnetic nuclei in macromolecules can easily be measured using high-resolution NMR methods when the molecules are dissolved in dilute liquid crystalline media. The resulting couplings can in principle be used to constrain the relative orientation of molecular fragments in macromolecular systems to build a complete structure. However, determination of relative fragment orientations based on a single set of residual dipolar couplings is inherently hindered by the multi-valued nature of the angular dependence of the dipolar interaction. Even with unlimited dipolar data, this gives rise to a fourfold degeneracy in fragment orientations. In this Communication, we demonstrate a procedure based on an order tensor analysis that completely removes this degeneracy by combining residual dipolar coupling measurements from two alignment media. Application is demonstrated on N-15-H-1 residual dipolar coupling data acquired on the protein zinc rubredoxin from Clostridium pasteurianum dissolved in two different bicelle media. (C) 2000 Academic Press.