Disrupted Hydrogen-Bond Network and Impaired ATPase Activity in an Hsc70 Cysteine Mutant.
Disrupted Hydrogen-Bond Network and Impaired ATPase Activity in an Hsc70 Cysteine Mutant.
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DOI：
10.1021/acs.biochem.7b01005
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发表时间：
2018-02-20
期刊：
影响因子：
2.9
通讯作者：
Sevier CS
中科院分区：
文献类型：
--
作者：
O'Donnell JP;Marsh HM;Sondermann H;Sevier CS
70 kDa热休克蛋白（Hsp70）家族成员的atp酶结构域在物种间具有高度的序列、结构和功能同源性。Hsp70 atp酶结构域中一个广泛保守的残基引起了我们的注意，它是一个未配对的半胱氨酸，位于核苷酸结合位点的近端。先前对几个Hsp70家族成员的研究表明，这种半胱氨酸不是Hsp70 ATP酶活性所必需的，但选择半胱氨酸的氨基酸替代物可以显著改变ATP水解。此外，据报道，半胱氨酸的翻译后修饰限制了几种hsp70的ATP水解。为了更好地理解这种非催化残基的扰动如何调节Hsp70功能的潜在机制，我们确定了组成性表达的哺乳动物Hsp70家族成员Hsc70中半胱氨酸到色氨酸突变的结构。我们的研究表明，由半胱氨酸到色氨酸突变产生的空间位阻破坏了活性位点内的氢键网络，导致适当的催化镁配位丧失。我们认为在翻译后氧化中可能观察到类似的活性位点改变。我们推测，我们在氢键网络中检测到的细微变化可能与先前报道的观察结果有关，即半胱氨酸氧化可以影响Hsp70域间通信。
The ATPase domain of members of the 70 kDa heat shock protein (Hsp70) family shows a high degree of sequence, structural, and functional homology across species. A broadly conserved residue within the Hsp70 ATPase domain that captured our attention is an unpaired cysteine, positioned proximal to the site of nucleotide binding. Prior studies of several Hsp70 family members show this cysteine is not required for Hsp70 ATPase activity, yet select amino acid replacements of the cysteine can dramatically alter ATP hydrolysis. Moreover, post-translational modification of the cysteine has been reported to limit ATP hydrolysis for several Hsp70s. To better understand the underlying mechanism for how perturbation of this noncatalytic residue modulates Hsp70 function, we determined the structure for a cysteine-to-tryptophan mutation in the constitutively expressed, mammalian Hsp70 family member Hsc70. Our work reveals that the steric hindrance produced by a cysteine-to-tryptophan mutation disrupts the hydrogen-bond network within the active site, resulting in a loss of proper catalytic magnesium coordination. We propose that a similarly altered active site is likely observed upon post-translational oxidation. We speculate that the subtle changes we detect in the hydrogen-bonding network may relate to the previously reported observation that cysteine oxidation can influence Hsp70 interdomain communication.
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影响因子：
5.6
作者：
Bhattacharya, Akash;Kurochkin, Alexander V.;Yip, Grover N. B.;Zhang, Yongbo;Bertelsen, Eric B.;Zuiderweg, Erik R. P.
通讯作者：
Zuiderweg, Erik R. P.
影响因子：
16
作者：
Kityk, Roman;Kopp, Juergen;Mayer, Matthias P.
通讯作者：
Mayer, Matthias P.
DOI：
10.1107/s0907444904019158
发表时间：
2004-12-01
影响因子：
2.2
作者：
Emsley, P;Cowtan, K
通讯作者：
Cowtan, K
影响因子：
4.8
作者：
English, Charles A.;Sherman, Woody;Gierasch, Lila M.
通讯作者：
Gierasch, Lila M.
影响因子：
4.8
作者：
Ha, JH;Hellman, U;Wilbanks, SM
通讯作者：
Wilbanks, SM