Structure of an enteric pathogen, bovine parvovirus

Area of Science:

• Virology
• Structural Biology
• Molecular Biology

Background:

• Bovine parvovirus (BPV) is a significant pathogen causing respiratory and gastrointestinal issues in cattle.
• BPV belongs to the Bocaparvovirus genus within the Parvoviridae family, known for causing infections in both animals and humans.
• The structure of BPV is essential for understanding its pathogenesis and for developing targeted interventions like vaccines and inhibitors.

Purpose of the Study:

• To determine the high-resolution structure of the BPV capsid.
• To provide a structural template for the development of vaccines and small-molecule inhibitors against BPV.
• To compare the BPV capsid structure with other bocaparvoviruses and parvoviruses to understand tropism and pathogenicity.

Main Methods:

• X-ray crystallography was employed to determine the BPV capsid structure to 3.2-Å resolution.
• Cryo-electron microscopy and three-dimensional image reconstruction (cryo-reconstruction) were used to achieve an 8.8-Å resolution.
• Analysis focused on the major capsid viral protein 2 (VP2) and its structural features.

Main Results:

• The BPV capsid structure conserves the common parvoviral eight-stranded jellyroll motif and an αA helix.
• Unique features include a raised surface loop at the 2-fold axes and extended N-terminal residues (29-38) in the interior channel.
• Surface loops exhibit high variability, conferring a unique topology distinct from other known bocaparvoviruses like human bocavirus 1 (HBoV1).

Conclusions:

• The determined BPV capsid structure provides critical insights into its molecular architecture.
• The unique surface topology, shaped by variable loops, likely influences receptor recognition, tropism, and pathogenicity.
• This structural information is vital for designing effective vaccines and antiviral therapies against bovine parvovirus.