The force-dependent mechanism of DnaK-mediated mechanical folding.
The force-dependent mechanism of DnaK-mediated mechanical folding.
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DOI：
10.1126/sciadv.aaq0243
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发表时间：
2018-03
期刊：
影响因子：
13.6
通讯作者：
Garcia-Manyes S
中科院分区：
文献类型：
--
作者：
Perales-Calvo J;Giganti D;Stirnemann G;Garcia-Manyes S
机械力调节机械折叠过程中分子伴侣与蛋白质底物结合的程度。众所周知，分子伴侣调节蛋白质折叠自由能景观。然而，分子伴侣介导的机械折叠的分子决定因素在很大程度上仍然难以捉摸，主要是因为力延伸的未折叠构象与生物化学实验中表征的构象根本不同。我们使用单分子力钳光谱结合分子动力学模拟来研究 Hsp70 系统对三种机械刚性模型蛋白质的机械折叠的影响。我们的结果表明，当独立工作时，DnaJ (Hsp40) 和 DnaK (Hsp70) 作为保持酶发挥作用，通过与不同的底物构象结合来阻止重折叠。 DnaK 与熔球状形式结合，而 DnaJ 以一种意想不到的力依赖方式识别延伸状态下的神秘序列。相比之下，Hsp70 系统的协同耦合表现出明显的折叠酶行为。我们的研究结果为机械力精细调节分子伴侣结合、直接影响蛋白质弹性的机制提供了前所未有的分子和动力学见解。
Mechanical force regulates the extent of chaperone binding to the protein substrate during mechanical folding. It is well established that chaperones modulate the protein folding free-energy landscape. However, the molecular determinants underlying chaperone-mediated mechanical folding remain largely elusive, primarily because the force-extended unfolded conformation fundamentally differs from that characterized in biochemistry experiments. We use single-molecule force-clamp spectroscopy, combined with molecular dynamics simulations, to study the effect that the Hsp70 system has on the mechanical folding of three mechanically stiff model proteins. Our results demonstrate that, when working independently, DnaJ (Hsp40) and DnaK (Hsp70) work as holdases, blocking refolding by binding to distinct substrate conformations. Whereas DnaK binds to molten globule–like forms, DnaJ recognizes a cryptic sequence in the extended state in an unanticipated force-dependent manner. By contrast, the synergetic coupling of the Hsp70 system exhibits a marked foldase behavior. Our results offer unprecedented molecular and kinetic insights into the mechanisms by which mechanical force finely regulates chaperone binding, directly affecting protein elasticity.
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影响因子：
64.5
作者：
Alegre-Cebollada J;Kosuri P;Giganti D;Eckels E;Rivas-Pardo JA;Hamdani N;Warren CM;Solaro RJ;Linke WA;Fernández JM
通讯作者：
Fernández JM
DOI：
10.1126/science.1261909
发表时间：
2015-04-24
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Goldman DH;Kaiser CM;Milin A;Righini M;Tinoco I Jr;Bustamante C
通讯作者：
Bustamante C
影响因子：
16.6
作者：
Beedle AEM;Mora M;Lynham S;Stirnemann G;Garcia-Manyes S
通讯作者：
Garcia-Manyes S
影响因子：
56.9
作者：
Fernandez, JM;Li, HB
通讯作者：
Li, HB
DOI：
10.1073/pnas.0901213106
发表时间：
2009-06-30
影响因子：
11.1
作者：
Garcia-Manyes, Sergi;Dougan, Lorna;Fernandez, Julio M.
通讯作者：
Fernandez, Julio M.