Abstact

White spot syndrome virus (WSSV) is a major serious threat to black tiger shrimp farming. WSSV infection induces a host protein, viral responsive protein 15 (VRP15), for viral assembly and nuclear egress. Here, we showed that the C-terminal tail of VRP15 (VRP15-C) interacts directly with the viral nucleocapsid tegument protein WSV399. The crystal structure of VRP15-C was determined at 1.5 Å. The structure showed that VRP15-C forms a dimer by forming an α-helix bundle structure and that the dimer further interacts with adjacent dimers to form a tetramer and a higher oligomer by intermolecular helix-helix interactions. The ability to form oligomeric forms may contribute to assembly of viral proteins to form a nucleocapsid of WSSV.