Conformational rearrangements of tail-less complex polypeptide 1 (TCP-1) ring complex (TRiC)-bound actin
Conformational rearrangements of tail-less complex polypeptide 1 (TCP-1) ring complex (TRiC)-bound actin
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DOI：
10.1021/bi062093o
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发表时间：
2007-05-01
期刊：
影响因子：
2.9
通讯作者：
Jonsson, Bengt-Harald
中科院分区：
文献类型：
--
作者：
Villebeck, Laila;Persson, Malin;Jonsson, Bengt-Harald
伴侣蛋白的作用机制仍在深入研究中。我们和其他人对细菌伴侣蛋白GroEL的早期研究指出，伴侣蛋白在初始结合过程中展开靶蛋白具有积极作用。本文研究了天然真核伴侣蛋白系统[无尾复合体多肽1 （TCP-1）环复合体（TRiC）及其靶蛋白肌动蛋白]，以确定伴侣蛋白在折叠过程中的积极参与是否具有进化保守性。利用荧光共振能量转移（FRET）测量四种不同的双荧光素标记的肌动蛋白变体，我们已经获得了在tricc -肌动蛋白相互作用期间发生的结构重排的相当详细的地图。结果清楚地表明，TRiC在重新排列结合的肌动蛋白分子中具有积极的作用。靶标由于与TRiC结合而被拉伸，并在第二步中由于ATP结合而进一步重排；也就是说，伴侣蛋白的作用机制在进化过程中是保守的。
The mechanism of chaperonins is still under intense investigation. Earlier studies by others and us on the bacterial chaperonin GroEL points to an active role of chaperonins in unfolding the target protein during initial binding. Here, a natural eukaryotic chaperonin system [tail-less complex polypeptide 1 (TCP-1) ring complex (TRiC) and its target protein actin] was investigated to determine if the active participation of the chaperonin in the folding process is evolutionary-conserved. Using fluorescence resonance energy transfer (FRET) measurements on four distinct doubly fluorescein-labeled variants of actin, we have obtained a fairly detailed map of the structural rearrangements that occur during the TRiC-actin interaction. The results clearly show that TRiC has an active role in rearranging the bound actin molecule. The target is stretched as a consequence of binding to TRiC and further rearranged in a second step as a consequence of ATP binding; i.e., the mechanism of chaperonins is conserved during evolution.