Crystal structures of the 70-kDa heat shock proteins in domain disjoining conformation
Crystal structures of the 70-kDa heat shock proteins in domain disjoining conformation
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DOI：
10.1074/jbc.m708992200
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发表时间：
2008-05-30
影响因子：
4.8
通讯作者：
Hsiao, Chwan-Deng
中科院分区：
文献类型：
--
作者：
Chang, Yi-Wei;Sun, Yuh-Ju;Hsiao, Chwan-Deng
70 kda热休克蛋白（Hsp7os）是高度保守的atp依赖分子伴侣，由双叶酸结构的n端核苷酸结合域（NBD）和c端蛋白底物结合域（SBD）组成。区域间通讯和核苷酸依赖的结构运动对Hsp70伴侣的功能至关重要。由于完整hsp70的结构信息不足，我们对这些功能的理解仍然难以捉摸，而完整hsp70代表了伴侣蛋白周期的不同状态。本文报道了kaustophilus Geobacillus HTA426与ADP-Mg2+-P-i在2.37埃和褐家鼠（Rattus norvegicus）与ADP-P-i在3.5埃结合的70 kda热休克同源蛋白的晶体结构。这些结构中的NBD和SBD彼此明显分离，它们可能描述了adp结合的构象。此外，在NBD与GkDnaK结构域间连接物之间的潜在界面区域引入Trp报告者，以探测环境变化。荧光测量结果支持底物结合增强Hsp70伴侣的结构域分离行为的观点。
The 70-kDa heat shock proteins (Hsp7os) are highly conserved ATP-dependent molecular chaperones composed of an N-terminal nucleotide binding domain (NBD) and a C-terminal protein substrate binding domain (SBD) in a bilobate structure. Interdomain communication and nucleotide-dependent structural motions are critical for Hsp70 chaperone functions. Our understanding of these functions remains elusive due to insufficient structural information on intact Hsp70s that represent the different states of the chaperone cycle. We report here the crystal structures of DnaK from Geobacillus kaustophilus HTA426 bound with ADP-Mg2+-P-i at 2.37 angstrom and the 70-kDa heat shock cognate protein from Rattus norvegicus bound with ADP-P-i at 3.5 angstrom. The NBD and SBD in these structures are significantly separated from each other, and they might depict the ADP-bound conformation. Moreover, a Trp reporter was introduced at the potential interface region between NBD and the interdomain linker of GkDnaK to probe environmental changes. Results from fluorescence measurements support the notion that substrate binding enhances the domain-disjoining behavior of Hsp70 chaperones.