Binding of ATP to heat shock protein 90 - Evidence for an ATP-binding site in the C-terminal domain
Binding of ATP to heat shock protein 90 - Evidence for an ATP-binding site in the C-terminal domain
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DOI：
10.1074/jbc.m111874200
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发表时间：
2002-04-05
影响因子：
4.8
通讯作者：
Peyrot, V
中科院分区：
文献类型：
--
作者：
Garnier, C;Lafitte, D;Peyrot, V
热休克蛋白90上的核苷酸结合位点的存在是非常有争议的，直到热休克蛋白90的N-末端结构域的X-射线结构，显示一个非常规的核苷酸结合位点，出现。最近的一项研究表明，hsp 90 C-末端结构域也结合ATP（Marcu，M. G.，Chadli，A.，Bouhouche，L，Catelli，M. G.，和Neckers，L. M.（2000）J.Biol.Chem.275，3718137186）。本文采用等温滴定量热法、差示扫描量热法和荧光光谱法研究了ATP与天然热休克蛋白90及其重组体N端（1-221位）和C端（446-728位）结构域的相互作用。结果清楚地表明，热休克蛋白90具有位于蛋白质的C-末端部分的第二个ATP结合位点。首次报道了热休克蛋白90的这个结构域与ATP-镁之间的结合常数，并与全长蛋白的结合常数进行了比较。二级结构预测显示图案兼容的Rossmann折叠的C-末端部分的热休克蛋白90。有人建议，这种潜在的Rossmann折叠可能构成的C-末端ATP结合位点。这项工作还表明热休克蛋白90的N-和C-末端结构域之间的变构相互作用。
The presence of a nucleotide binding site on hsp90 was very controversial until x-ray structure of the hsp90 N-terminal domain, showing a nonconventional nucleotide binding site, appeared. A recent study suggested that the hsp90 C-terminal domain also binds ATP (Marcu, M. G., Chadli, A., Bouhouche, L, Catelli, M. G., and Neckers, L. M. (2000) J. Biol. Chem. 275, 3718137186). In this paper, the interactions of ATP with native hsp90 and its recombinant N-terminal (positions 1-221) and C-terminal (positions 446-728) domains were studied by isothermal titration calorimetry, scanning differential calorimetry, and fluorescence spectroscopy. Results clearly demonstrate that hsp90 possesses a second ATP-binding site located on the C-terminal part of the protein. The association constant between this domain of hsp90 and ATP-Mg and a comparison with the binding constant on the full-length protein are reported for the first time. Secondary structure prediction revealed motifs compatible with a Rossmann fold in the C-terminal part of hsp90. It is proposed that this potential Rossmann fold may constitute the C-terminal ATP-binding site. This work also suggests allosteric interaction between N- and C-terminal domains of hsp90.