Characterization of tubule and monomer derived from VP4 protein of infectious bursal disease virus.

Highlights: [•] VP4 protein of infectious bursal disease virus (IBDV) self-cleavages at a VP4 cleavage site in Escherichia coli and forms tubules thereafter. [•] Deletion of 28 amino acids at the C-terminus of VP4 resulted in both VP4 monomers and dimers instead of tubule formation. [•] The endopeptidase activity of these VP4 monomers and dimers was about 12.5 times higher than that of VP4 tubules. [•] Formation of VP4 tubules inhibits VP4 protease activity. [ABSTRACT FROM AUTHOR]