Structural basis for the removal of ubiquitin and interferon-stimulated gene 15 by a viral ovarian tumor domain-containing protease
Structural basis for the removal of ubiquitin and interferon-stimulated gene 15 by a viral ovarian tumor domain-containing protease
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DOI：
10.1073/pnas.1013388108
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发表时间：
2011-02-08
影响因子：
11.1
通讯作者：
Mark, Brian L.
中科院分区：
文献类型：
--
作者：
James, Terrence W.;Frias-Staheli, Natalia;Mark, Brian L.
泛素（Ub）和Ub样（Ubl）分子干扰素刺激基因15（ISG 15）与细胞蛋白的连接介导重要的先天性抗病毒反应。最近发现来自内罗病毒和动脉炎病毒的卵巢肿瘤（OTU）结构域蛋白酶从宿主蛋白中去除这些分子，这抑制Ub和ISG 15依赖性抗病毒途径。这与已知的真核OTU结构域蛋白酶的Ub特异性活性形成对比。在这里，我们描述了高致病性克里米亚-刚果出血热病毒（CCHFV）的病毒OTU域的晶体结构结合到Ub和ISG 15在2.5埃和2.3埃的分辨率，分别。该复合物提供了ISG 15与另一种蛋白质结合的独特结构实例，并揭示了ISG 15交叉反应性去泛素化酶的分子机制。为了适应Ub和ISG 15之间的结构差异，病毒蛋白酶以相对于结合至来自酵母的代表性真核OTU结构域的Ub所观察到的方向旋转近75度的方向结合Ub的β-抓握折叠和ISG 15的C-末端Ub样结构域。鉴定了结合任一底物所需的不同结构决定簇，并允许将病毒OTU蛋白酶重新工程改造成对Ub或ISG 15具有增加的底物特异性的酶。我们的研究结果现在提供了基础，以确定在体内的相对贡献的去泛素化和去ISGylation病毒的免疫逃避策略，和一个混杂的去泛素化酶的结构模板，从出血热病毒，可以有针对性的抑制使用小分子为基础的策略。
The attachment of ubiquitin (Ub) and the Ub-like (Ubl) molecule interferon-stimulated gene 15 (ISG15) to cellular proteins mediates important innate antiviral responses. Ovarian tumor (OTU) domain proteases from nairoviruses and arteriviruses were recently found to remove these molecules from host proteins, which inhibits Ub and ISG15-dependent antiviral pathways. This contrasts with the Ub-specific activity of known eukaryotic OTU-domain proteases. Here we describe crystal structures of a viral OTU domain from the highly pathogenic Crimean-Congo haemorrhagic fever virus (CCHFV) bound to Ub and to ISG15 at 2.5-angstrom and 2.3-angstrom resolution, respectively. The complexes provide a unique structural example of ISG15 bound to another protein and reveal the molecular mechanism of an ISG15 cross-reactive deubiquitinase. To accommodate structural differences between Ub and ISG15, the viral protease binds the beta-grasp folds of Ub and C-terminal Ub-like domain of ISG15 in an orientation that is rotated nearly 75 degrees with respect to that observed for Ub bound to a representative eukaryotic OTU domain from yeast. Distinct structural determinants necessary for binding either substrate were identified and allowed the reengineering of the viral OTU protease into enzymes with increased substrate specificity, either for Ub or for ISG15. Our findings now provide the basis to determine in vivo the relative contributions of deubiquitination and deISGylation to viral immune evasion tactics, and a structural template of a promiscuous deubiquitinase from a haemorrhagic fever virus that can be targeted for inhibition using small-molecule-based strategies.