Structural basis of HIV-1 capsid recognition by PF74 and CPSF6
Structural basis of HIV-1 capsid recognition by PF74 and CPSF6
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DOI：
10.1073/pnas.1419945112
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发表时间：
2014-12-30
影响因子：
11.1
通讯作者：
Yeager, Mark
中科院分区：
文献类型：
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作者：
Bhattacharya, Akash;Alam, Steven L.;Yeager, Mark
在易感细胞被HIV-1感染后，由CA蛋白的类似250个六聚体和12个五聚体形成的锥形衣壳被递送到细胞质。衣壳保护逆转录所需的RNA基因组和蛋白质。此外，衣壳的表面介导许多宿主-病毒相互作用，其通过先天免疫应答促进感染或实现病毒限制。在完整的衣壳中，在同一个六聚体环内，一个亚基的N端结构域（NTD）和相邻亚基的C端结构域（CTD）之间存在分子间界面。NTD-CTD界面对于衣壳组装是至关重要的，既作为CA六聚体和五聚体的结构元件，又作为用于产生晶格曲率的机械元件。在这里，我们报告的生化实验表明，PF-3450074（PF 74），一种药物，抑制HIV-1感染，以及宿主蛋白裂解和多聚腺苷酸化特异性因子6（CPSF 6）和核孔蛋白153 kDa（NUP 153），结合到CA六聚体的亲和力至少比未组装的CA或分离的CA结构域高10倍。与CA六聚体复合的PF 74的晶体结构揭示PF 74结合在包围NTD-CTD界面的预先形成的口袋中，表明PF 74的主要抑制靶标是组装的衣壳。同样，CPSF 6结合在相同的口袋中。鉴于NTD-CTD界面是衣壳中组装的六聚体的特异性分子标记，NUP 153在该位点的结合表明，衣壳结构的关键特征在整合前复合物递送至核后保持完整。
Upon infection of susceptible cells by HIV-1, the conical capsid formed by similar to 250 hexamers and 12 pentamers of the CA protein is delivered to the cytoplasm. The capsid shields the RNA genome and proteins required for reverse transcription. In addition, the surface of the capsid mediates numerous host-virus interactions, which either promote infection or enable viral restriction by innate immune responses. In the intact capsid, there is an intermolecular interface between the N-terminal domain (NTD) of one subunit and the Cterminal domain (CTD) of the adjacent subunit within the same hexameric ring. The NTD-CTD interface is critical for capsid assembly, both as an architectural element of the CA hexamer and pentamer and as a mechanistic element for generating lattice curvature. Here we report biochemical experiments showing that PF-3450074 (PF74), a drug that inhibits HIV-1 infection, as well as host proteins cleavage and polyadenylation specific factor 6 (CPSF6) and nucleoporin 153 kDa (NUP153), bind to the CA hexamer with at least 10-fold higher affinities compared with nonassembled CA or isolated CA domains. The crystal structure of PF74 in complex with the CA hexamer reveals that PF74 binds in a preformed pocket encompassing the NTD-CTD interface, suggesting that the principal inhibitory target of PF74 is the assembled capsid. Likewise, CPSF6 binds in the same pocket. Given that the NTD-CTD interface is a specificmolecular signature of assembled hexamers in the capsid, binding of NUP153 at this site suggests that key features of capsid architecture remain intact upon delivery of the preintegration complex to the nucleus.