4 HELIX BUNDLE DIVERSITY IN GLOBULAR-PROTEINS
4 HELIX BUNDLE DIVERSITY IN GLOBULAR-PROTEINS
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DOI：
10.1016/0022-2836(94)90063-9
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发表时间：
1994-03-11
影响因子：
5.6
通讯作者：
COHEN, FE
中科院分区：
文献类型：
--
作者：
HARRIS, NL;PRESNELL, SR;COHEN, FE
四螺旋束是一种常见的结构基序，既可以独立观察到，也可以作为较大折叠单位的组成部分。我们研究了221个已知结构的球状蛋白质可能的四个螺旋束。以前的计算研究的四个螺旋束放置任意限制螺旋间的包装角。在这项研究中，我们开发了一个几何定义的四个螺旋束的基础上，部分溶剂的可及性标准，允许去除螺旋间包装的限制。根据观察到的螺旋间角的模式，束分类。这一方法为将来研究富含α α螺旋的蛋白质的结构提供了一种有效的分类方法。中心残基，接触法线和斜角都被观察到具有非随机分布。一个简单的几何模型的螺旋-螺旋界面来解释这些发现。在这项工作中收集的螺旋-螺旋相互作用数据的分析证实了包括螺旋包装模型中的斜角的重要性，并应提高预测全螺旋蛋白质三级结构的组合策略的准确性。此外，在球状蛋白中观察到的几何性质提供了对跨膜蛋白的结构组织的深入了解。
Four helix.bundles are a common structural motif that can be observed both independently and as components of larger folding units. We examined 221 globular proteins of known structure for possible four helix bundles. Previous computational studies of four helix bundles have placed arbitrary restrictions on interhelical packing angles. In this study we develop a geometric definition of four helix bundles based in part on solvent accessibility criteria that permits the removal of constraints on interhelical packing. Based on the observed pattern of interhelical angles, a bundle taxonomy is presented. This formalism should provide a useful categorization method for future structural studies of proteins rich in αa-helices.The helix-helix interactions within bundles were studied in detail. Central residues, contact normals, and skew angles all were observed to have non-random distributions. A simple geometric model was developed for the helix-helix interface to explain these findings. Analysis of the helix-helix interaction data collected in this work confirms the importance of including skew angles in models of helix packing, and should improve the accuracy of combinatorial strategies for the prediction of the tertiary structure of all-helical proteins. Additionally, the geometric properties observed in globular proteins provide insight into the structural organization of membrane spanning proteins.