Characterization and Structural Studies of the Plasmodium falciparum Ubiquitin and Nedd8 Hydrolase UCHL3
Characterization and Structural Studies of the Plasmodium falciparum Ubiquitin and Nedd8 Hydrolase UCHL3
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DOI：
10.1074/jbc.m109.072405
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发表时间：
2010-02-26
影响因子：
4.8
通讯作者：
Ploegh, Hidde L.
中科院分区：
文献类型：
--
作者：
Artavanis-Tsakonas, Katerina;Weihofen, Wilhelm A.;Ploegh, Hidde L.
与人类宿主一样，恶性疟原虫依靠泛素-蛋白酶体系统生存。我们以前确定PfUCHL 3，去泛素化酶，在这里，我们表征其活性和活性位点结构的变化后，结合到泛素。我们发现了强有力的证据，PfUCHL 3对寄生虫的生存至关重要。PfUCHL 3单独和与基于泛素的自杀底物UbVME复合的晶体结构表明，相当刚性的活性位点交叉环可能在限制泛素加合物底物的大小中起作用。PfUCHL 3-PfNedd 8复合物的结构和模型的分子动力学模拟允许鉴定泛素和PfNedd 8与PfUCHL 3的共享关键相互作用，解释了这种酶的双重特异性。在PfUCHL 3与其人类对应物之间的泛素结合中观察到的明显差异使得可能可以选择性地靶向寄生DUB，同时使人类酶不受影响。
Like their human hosts, Plasmodium falciparum parasites rely on the ubiquitin-proteasome system for survival. We previously identified PfUCHL3, a deubiquitinating enzyme, and here we characterize its activity and changes in active site architecture upon binding to ubiquitin. We find strong evidence that PfUCHL3 is essential to parasite survival. The crystal structures of both PfUCHL3 alone and in complex with the ubiquitin-based suicide substrate UbVME suggest a rather rigid active site crossover loop that likely plays a role in restricting the size of ubiquitin adduct substrates. Molecular dynamics simulations of the structures and a model of the PfUCHL3-PfNedd8 complex allowed the identification of shared key interactions of ubiquitin and PfNedd8 with PfUCHL3, explaining the dual specificity of this enzyme. Distinct differences observed in ubiquitin binding between PfUCHL3 and its human counterpart make it likely that the parasitic DUB can be selectively targeted while leaving the human enzyme unaffected.