Structural insights into mink enteritis virus host specificity: capsid architecture, receptor recognition, and evolutionary dynamics

Mink enteritis virus (MEV), a member of the Protoparvovirus genus within the Parvovirinae subfamily, causes severe hemorrhagic enteritis and leukopenia in minks, thus representing a serious economic threat to mink farming. MEV, feline panleukopenia virus (FPV), and canine parvovirus (CPV) are closely related Protoparvovirus members; CPV and FPV infect hosts via binding to transferrin receptor 1 (TfR1). However, the structural mechanism of MEV entry remains poorly understood. This study used cryo-electron microscopy (cryo-EM) and structural bioinformatics to determine the structure of MEV virus-like particles at 2.5 Å resolution. The analysis revealed that MEV shares a highly conserved capsid architecture with CPV and FPV, particularly in the β-barrel core and three-fold protrusions. We predict that MEV utilizes mink TfR1 for host entry, similar to CPV and FPV. Structural superposition and sequence alignment identified key residues in the MEV VP2 protein that are critical for mink TfR1 interaction. These findings provide structural and evolutionary insights into MEV host tropism, offering valuable information for efforts to mitigate the zoonotic risks of mammalian parvoviruses.