Serotype-Specific Structural Differences in the Protease-Cofactor Complexes of the Dengue Virus Family
Serotype-Specific Structural Differences in the Protease-Cofactor Complexes of the Dengue Virus Family
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DOI：
10.1128/jvi.02044-09
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发表时间：
2010-03-01
影响因子：
5.4
通讯作者：
Kuhn, Peter
中科院分区：
文献类型：
--
作者：
Chandramouli, Sumana;Joseph, Jeremiah S.;Kuhn, Peter
估计有40%的世界人口处于危险之中，登革热对人类健康构成重大威胁，特别是在热带和亚热带地区。预防性和治疗性的努力，如疫苗开发和药物发现，面临着额外的挑战，由于四种抗原性不同的血清型的致病性登革热病毒（DEN1至-4）的出现。由不同血清型的重复攻击引起的复杂免疫应答需要同时靶向所有形式的病毒。高度保守的双组分病毒蛋白酶NS2B-NS3是药物开发的有希望的靶点之一，其通过将病毒前体多蛋白加工成功能蛋白而在病毒复制中起重要作用。在本文中，我们报告了DEN1 NS2B亲水核心（残基49至95）与NS3蛋白酶结构域（残基1至186）复合的2.1埃晶体结构，该结构域在N末端（残基11至20）携带内部缺失。虽然蛋白酶核心内的总体折叠与DEN2和DEN4蛋白酶的折叠相似，但辅因子NS2B的构象与其他黄病毒脱辅基蛋白酶结构的构象显著不同。这种差异在其C-末端区域尤其明显，涉及底物结合。该结构首次揭示了登革病毒家族中的病毒型特异性结构元件，并报告了DEN1序列内独特的金属结合位点导致的交替构象。我们还报告了NS 3 pro内10个残基片段的鉴定，该片段将底物结合功能与酶的催化周转率分开。广谱药物发现的影响进行了讨论。
With an estimated 40% of the world population at risk, dengue poses a significant threat to human health, especially in tropical and subtropical regions. Preventative and curative efforts, such as vaccine development and drug discovery, face additional challenges due to the occurrence of four antigenically distinct serotypes of the causative dengue virus (DEN1 to -4). Complex immune responses resulting from repeat assaults by the different serotypes necessitate simultaneous targeting of all forms of the virus. One of the promising targets for drug development is the highly conserved two-component viral protease NS2B-NS3, which plays an essential role in viral replication by processing the viral precursor polyprotein into functional proteins. In this paper, we report the 2.1-angstrom crystal structure of the DEN1 NS2B hydrophilic core (residues 49 to 95) in complex with the NS3 protease domain (residues 1 to 186) carrying an internal deletion in the N terminus (residues 11 to 20). While the overall folds within the protease core are similar to those of DEN2 and DEN4 proteases, the conformation of the cofactor NS2B is dramatically different from those of other flaviviral apoprotease structures. The differences are especially apparent within its C-terminal region, implicated in substrate binding. The structure reveals for the first time serotype-specific structural elements in the dengue virus family, with the reported alternate conformation resulting from a unique metal-binding site within the DEN1 sequence. We also report the identification of a 10-residue stretch within NS3pro that separates the substrate-binding function from the catalytic turnover rate of the enzyme. Implications for broad-spectrum drug discovery are discussed.