The structural basis of African swine fever virus pA104R binding to DNA and its inhibition by stilbene derivatives
The structural basis of African swine fever virus pA104R binding to DNA and its inhibition by stilbene derivatives
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DOI：
10.1073/pnas.1922523117
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发表时间：
2020-05-19
影响因子：
11.1
通讯作者：
Wang, Han
中科院分区：
文献类型：
--
作者：
Liu, Ruili;Sun, Yeping;Wang, Han
非洲猪瘟病毒（African Swine Fever Virus，ASFV）是一种高度传染性的核质大DNA病毒（Nucleocytoplasmic Large DNA virus，NCLDV），可引起猪100%的死亡。迫切需要研制针对这种病毒的有效疫苗和药物。pA 104 R是一种ASFV衍生的组蛋白样蛋白，与细菌HU/IHF家族成员具有序列和功能相似性，并且对于病毒复制至关重要。在此，我们解决了pA 104 R在其apo状态以及与DNA的复合物中的晶体结构。Apo-pA 104 R形成同源二聚体并折叠成在细菌热不稳定类核蛋白/整合宿主因子（HU/IHF）中保守的结构。然而，pA 104 R-DNA复合物结构揭示了pA 104 R具有与其细菌同系物不同的DNA结合模式，即，pA 104 R的β-带臂通过接触大沟而不是小沟来稳定DNA结合。β链DNA结合区（BDR）碱基区域的碱基残基突变，而不是β带臂中的碱基残基突变，完全消除了DNA结合，突出了BDR碱基在DNA结合中的主要作用。在pA 104 R-DNA复合物结构的晶体堆积中观察到93.8 °的总DNA弯曲角，这与HU-DNA复合物中的DNA弯曲角接近。二苯乙烯衍生物SD 1和SD 4能破坏pA 104 R与DNA的结合，抑制ASFV在原代猪肺泡巨噬细胞中的复制。总的来说，这些结果揭示了pA 104 R与DNA结合的结构基础，强调了pA 104 R-DNA相互作用在ASFV复制周期中的重要性，并为ASFV化疗提供了抑制剂线索。
African swine fever virus (ASFV) is a highly contagious nucleocytoplasmic large DNA virus (NCLDV) that causes nearly 100% mortality in swine. The development of effective vaccines and drugs against this virus is urgently needed. pA104R, an ASFV-derived histone-like protein, shares sequence and functional similarity with bacterial HU/IHF family members and is essential for viral replication. Herein, we solved the crystal structures of pA104R in its apo state as well as in complex with DNA. Apo-pA104R forms a homodimer and folds into an architecture conserved in bacterial heat-unstable nucleoid proteins/integration host factors (HUs/IHFs). The pA104R-DNA complex structure, however, uncovers that pA104R has a DNA binding pattern distinct from its bacterial homologs, that is, the beta-ribbon arms of pA104R stabilize DNA binding by contacting the major groove instead of the minor groove. Mutations of the basic residues at the base region of the beta-strand DNA binding region (BDR), rather than those in the beta-ribbon arms, completely abolished DNA binding, highlighting the major role of the BDR base in DNA binding. An overall DNA bending angle of 93.8 degrees isobserved in crystal packing of the pA104R-DNA complex structure, which isclose to the DNA bending angle in the HU-DNA complex. Stilbene derivatives SD1 and SD4 were shown to disrupt the binding between pA104R and DNA and inhibit the replication of ASFV in primary porcine alveolar macrophages. Collectively, these results reveal the structural basis of pA104R binding to DNA highlighting the importance of the pA104R-DNA interaction in the ASFV replication cycle and provide inhibitor leads for ASFV chemotherapy.