Substrate occupancy at the onset of oligomeric transitions of DegP.
Substrate occupancy at the onset of oligomeric transitions of DegP.
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DOI：
10.1016/j.str.2013.11.010
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发表时间：
2014-02
期刊：
影响因子：
5.7
通讯作者：
Natalie J. Thompson;Melisa Merdanovic;M. Ehrmann;E. van Duijn;A. Heck
中科院分区：
文献类型：
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作者：
Natalie J. Thompson;Melisa Merdanovic;M. Ehrmann;E. van Duijn;A. Heck
蛋白酶伴侣DegP经历二级至四级结构变化，调节功能并防止不加选择的蛋白水解。已观察到DegP寡聚体的几种结构，包括静息状态6-mer和12-mer和24-mer活性状态。然而，休息和活动状态之间的过渡的确切事件仍然需要阐明。我们使用天然质谱证明，结合多个底物模拟肽配体的DegP静息状态之前发生的过渡到活性构象。对于每个肽配体，这种转变发生在40%的6聚体占有率。我们观察到配体特异性9聚体形成的最大负载9肽，而其他基板导致12聚体容纳24肽。基于这些数据，我们提出了一个模型的初始步骤的底物诱导的过渡从休息到活动状态的DegP。
The protease-chaperone DegP undergoes secondary through quaternary structural changes, regulating function and preventing indiscriminate proteolysis. Several structures of DegP oligomers have been observed, including the resting state 6-mer and the 12-mer and 24-mer active states. However, the precise events of the transition between the resting and active states still need to be elucidated. We used native mass spectrometry to demonstrate that binding of multiple substrate-mimicking peptide ligands to the DegP resting state occurs prior to the transition to an active conformation. This transition occurred at a 6-mer occupancy of 40% for each peptide ligand. We observed ligand-specific 9-mer formation with a maximum load of 9 peptides, whereas other substrates led to 12-mers accommodating 24 peptides. Based on these data, we present a model for the initial steps of substrate-induced transitions from the resting to active states of DegP.