Miller Erik J, Meyer Anne S, Frydman Judith
Department of Biological Sciences, Stanford University, Stanford, California 94305, USA.
Protein Sci. 2006 Jun;15(6):1522-6. doi: 10.1110/ps.052001606. Epub 2006 May 2.
The eukaryotic cytosolic chaperonin TRiC (TCP-1 Ring Complex), also known as CCT (Cytosolic Chaperonin containing TCP-1), is a hetero-oligomeric complex consisting of two back-to-back rings of eight different subunits each. The general architecture of the complex has been determined, but the arrangement of the subunits within the complex remains an open question. By assuming that the subunits have a defined arrangement within each ring, we constructed a simple model of TRiC that analyzes the possible arrangements of individual subunits in the complex. By applying the model to existing data, we find that there are only four subunit arrangements consistent with previous observations. Our analysis provides a framework for the interpretation and design of experiments to elucidate the quaternary structure of TRiC/CCT. This in turn will aid in the understanding of substrate binding and allosteric properties of this chaperonin.
真核细胞胞质伴侣蛋白TRiC（TCP-1环复合物），也称为CCT（含TCP-1的胞质伴侣蛋白），是一种异源寡聚复合物，由两个背靠背的环组成，每个环包含八个不同的亚基。该复合物的总体结构已确定，但复合物内亚基的排列仍然是一个悬而未决的问题。通过假设亚基在每个环内有确定的排列方式，我们构建了一个TRiC的简单模型，该模型分析了复合物中单个亚基的可能排列。通过将该模型应用于现有数据，我们发现只有四种亚基排列与先前的观察结果一致。我们的分析为解释和设计阐明TRiC/CCT四级结构的实验提供了一个框架。这反过来将有助于理解这种伴侣蛋白的底物结合和变构特性。
