Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany.
Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany.
Trends Biochem Sci. 2016 Jan;41(1):62-76. doi: 10.1016/j.tibs.2015.07.009. Epub 2015 Sep 25.
The bacterial chaperonin GroEL and its cofactor GroES constitute the paradigmatic molecular machine of protein folding. GroEL is a large double-ring cylinder with ATPase activity that binds non-native substrate protein (SP) via hydrophobic residues exposed towards the ring center. Binding of the lid-shaped GroES to GroEL displaces the bound protein into an enlarged chamber, allowing folding to occur unimpaired by aggregation. GroES and SP undergo cycles of binding and release, regulated allosterically by the GroEL ATPase. Recent structural and functional studies are providing insights into how the physical environment of the chaperonin cage actively promotes protein folding, in addition to preventing aggregation. Here, we review different models of chaperonin action and discuss issues of current debate.
细菌伴侣蛋白 GroEL 和其辅助因子 GroES 构成了蛋白质折叠的典型分子机器。GroEL 是一个具有 ATP 酶活性的大环双圆柱，通过暴露在环中心的疏水性残基结合非天然底物蛋白（SP）。盖状的 GroES 与 GroEL 的结合将结合的蛋白置换到一个扩大的腔室中，允许折叠不受聚集的影响。GroES 和 SP 经历结合和释放的循环，由 GroEL ATP 酶的变构调节。最近的结构和功能研究为我们提供了关于伴侣蛋白笼的物理环境如何除了防止聚集外，还能积极促进蛋白质折叠的见解。在这里，我们回顾了不同的伴侣蛋白作用模型，并讨论了当前争论的问题。
