A nucleotide-dependent molecular switch controls ATP binding at the C-terminal domain of Hsp90 -: N-terminal nucleotide binding unmasks a C-terminal binding pocket
A nucleotide-dependent molecular switch controls ATP binding at the C-terminal domain of Hsp90 -: N-terminal nucleotide binding unmasks a C-terminal binding pocket
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DOI：
10.1074/jbc.m105568200
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发表时间：
2002-03-01
影响因子：
4.8
通讯作者：
Csermely, P
中科院分区：
文献类型：
--
作者：
Söti, C;Rácz, A;Csermely, P
分子伴侣Hsp 90的体内功能是ATP依赖性的，并且需要全长蛋白。我们早期的研究预测了热休克蛋白90的第二个C-末端ATP结合位点。通过应用直接的生物化学方法，我们绘制了两个ATP结合位点，并揭开了C-末端ATP结合位点作为一个神秘的伴侣核苷酸结合位点，这是开放的N-末端位点的占用的第一个例子。我们在Hsp 90的中间结构域中发现了一个类似于其他GHKL家族成员的N-末端γ-磷酸结合基序。该基序与C-末端ATP结合位点的磷酸结合区相邻。而新生霉素破坏C-和N-末端核苷酸结合，我们发现了一个选择性的C-末端核苷酸竞争对手，顺铂，加强热休克蛋白90-热休克蛋白70复合物离开热休克蛋白90-p23复合物完整。顺铂可以提供一种药理学工具来剖析热休克蛋白90的C-和N-末端核苷酸结合。提出了一个模型的两个核苷酸结合结构域和Hsp 90的带电区域的相互作用。
In vivo function of the molecular chaperone Hsp90 is ATP-dependent and requires the full-length protein. Our earlier studies predicted a second C-terminal ATP-binding site in Hsp90. By applying direct biochemical approaches, we mapped two ATP-binding sites and unveiled the C-terminal ATP-binding site as the first example of a cryptic chaperone nucleotide-binding site, which is opened by occupancy of the N-terminal site. We identified an N-terminal gamma-phosphate-binding motif in the middle domain of Hsp90 similar to other GHKL family members. This motif is adjacent to the phosphate-binding region of the C-terminal ATP-binding site. Whereas novobiocin disrupts both C- and N-terminal nucleotide binding, we found a selective C-terminal nucleotide competitor, cisplatin, that strengthens the Hsp90-Hsp70 complex leaving the Hsp90-p23 complex intact. Cisplatin may provide a pharmacological tool to dissect C- and N-terminal nucleotide binding of Hsp90. A model is proposed on the interactions of the two nucleotide-binding domains and the charged region of Hsp90.