Structural prediction of porcine sialoadhesin V-set Ig-like domain sheds some light on its role in porcine reproductive and respiratory syndrome virus (PRRSV) infection

Porcine reproductive and respiratory syn- drome (PRRS) is characterized by reproductive failures in sows and respiratory diseases in pigs of all ages. PRRS virus (PRRSV) is its causative agent and has caused huge economic losses in the swine industry. Porcine sialoadhe- sin (pSn) is a putative receptor of PRRSV. Previous studies have shown that a pSn V-set Ig-like domain is significant in PRRSVinfection. However, its structural details are not fully known, hindering our deep understanding of PRRSV infection. In this study, we successfully cloned, expressed and purified the pSn V-set Ig-like domain in Drosophila S2 cells. Then we tried to crystallize the target protein and predicted its structure. This will establish the foundation for the further structural study of pSn, deepen our understanding of the invasion mechanism of PRRSV, and support the structural information for the development of clinical drugs and vaccines against PRRSV.