Thonningianin A disrupts pA104R−DNA binding and inhibits African swine fever virus replication

African swine fever is a highly lethal disease caused by the African swine fever virus (ASFV), posing a significant threat to the global pig industry, wherease no approved treatments are currently available. The ASFV DNA-binding protein, pA104R, plays a critical role in viral genome packaging and replication, making it a key target for drug discovery. Through structure-based virtual screening, we identified a polyphenolic compound, thonningianin A, which disrupts the pA104R−DNA binding and significantly inhibits ASFV replication. Mechanistic study revealed that thonningianin A binds to the DNA-binding region of pA104R, forming strong hydrogen bonds with H100 and occupying the vital DNA-binding residues K92, R94, and K97. In addition, we resolved the high-resolution (1.8 Å) structure of pA104R (PDB ID 9JS5), providing valuable insights for future drug screening. Together, these results demonstrate that thonningianin A holds great potential for the development of anti-ASFV drug, as a herb extract with favourable pharmacokinetic properties and safety.

非洲猪瘟（African swine fever, ASF）是由非洲猪瘟病毒（African swine fever virus, ASFV）引发的极高致死性疫病，对全球养猪业构成严重威胁，而目前尚无获批的治疗手段。非洲猪瘟病毒的DNA结合蛋白pA104R在病毒基因组包装与复制过程中发挥关键作用，是药物研发的核心靶点。通过基于结构的虚拟筛选，我们发现一种多酚类化合物——托南辛A（thonningianin A），可阻断pA104R与DNA的结合，并显著抑制ASFV的复制。机制研究显示，托南辛A结合至pA104R的DNA结合区域，与H100形成强氢键，并占据关键DNA结合残基K92、R94与K97。此外，我们解析了pA104R的高分辨率（1.8埃）结构（PDB编号：9JS5），为后续药物筛选提供了重要参考。综上，这些研究结果表明，作为一种具有良好药代动力学特性与安全性的草本提取物，托南辛A在抗ASFV药物开发方面具有巨大潜力。