The Native GCN4 Leucine-Zipper Domain Does Not Uniquely Specify a Dimeric Oligomerization State
The Native GCN4 Leucine-Zipper Domain Does Not Uniquely Specify a Dimeric Oligomerization State
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DOI：
10.1021/bi301132k
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发表时间：
2012-11-27
期刊：
影响因子：
2.9
通讯作者：
Horne, W. Seth
中科院分区：
文献类型：
--
作者：
Oshaben, Kaylyn M.;Salari, Reza;Horne, W. Seth
二聚化。酵母转录因子GCN 4的结构域，第一个卷曲螺旋之一：有待结构表征的蛋白质。高分辨率，已成为许多基础研究的α-螺旋折叠的基础。已知GCN 4亮氨酸拉链中的突变会改变其偏好。低聚反应状态从二聚体到三聚体或四聚体;然而，野生型序列已被假定编码，仅为两链组装。在这里，我们证明了GCN 4卷曲螺旋结构域可以填充二聚体或三聚体折叠，这取决于环境。我们报告了野生型序列在二聚体和三聚体组装体中的高分辨率晶体结构。生物物理测量表明，在某些实验条件下，在溶液中的低聚化状态的人口：我们使用并行回火分子动力学模拟微秒的时间尺度上比较的二聚体和三聚体折叠状态的稳定性隔离。总之，我们的结果表明，折叠行为的良好研究。GCN 4亮氨酸拉链结构域比以前认识到的更复杂我们的结果对建立卷曲螺旋折叠的预测算法以及选择用于设计和突变研究的卷曲螺旋模型系统的持续努力具有影响，其中寡聚化状态特异性是一个重要的考虑因素：
The dimerization. domain of the yeast transcription factor GCN4, one of the first coiled coil :proteins to be structurally characterized. high resolution, has served as the basis for numerous fundamental studies on a-helical folding. Mutations in the GCN4 leucine zipper are known to change its preferred. oligomerization. State from dimeric to trimeric or tetrameric; however, the wild type sequence has been assumed to encode,a two chain assembly exclusively. Here we demonstrate that the GCN4 coiled coil domain can populate either a dimer or trimer fold, depending on environment. We report high resolution crystal structures of the wild type sequence in dimeric and trimeric assemblies. Biophysical measurements suggest populations of both oligomerization states under certain experimental conditions in solution: We use parallel tempering molecular dynamics simulations on the microsecond time scale to compare the stability of the dimer and trimer folded States in isolation. In total, our results Suggest that the folding behavior of the well-studied. GCN4 leucine-zipper domain is more complex than Was previously appreciated Our results have implications in ongoing efforts to establish predictive algorithms for coiled-coil folds and the selection of coiled-coil model systems for design and mutational studies where oligomerization State specificity is an important consideration: