Multiple coding sequences for the genome-linked virus protein (VPg) in dicistroviruses

N-terminal Edman sequencing of the genome-linked viral protein (VPg) of Plautia stali intestine virus (PSIV, Dicistroviridae) detected heterologus residues. The VPg sequence determined was found to be triplicated in the nonstructural protein precursor. Multiple VPg-like sequences were also found in 10 of the 12 dicistroviruses with a maximum of six copies in Solenopsis invicta virus-1. We postulate that redundant VPg coding sequences facilitate multiplication of dicistroviruses, because fewer cycle of translation of the nonstructural protein precursor produces larger amounts of VPg proteins in parallel with the increased production of capsid proteins by the intergenic internal ribosome entry site mediated translation.