Aichi virus 2A protein is involved in viral RNA replication

The Aichi virus 2A protein is not a protease, unlike many other picornavirus 2A proteins, and it is related to a cellular protein, H-rev107. Here, we examined the replication properties of two 2A mutants in Vero cells and a cell-free translation/replication system. In one mutant, amino acids 36 to 126 were replaced with an unrelated amino acid sequence. In the other mutant, the NC motif conserved in the H-rev107 family of proteins was changed to alanine residues. The two mutations abolished virus replication in cells. The mutations affected both negative- and positive-strand synthesis, the defect in positive-strand synthesis being more severe than that in negative-strand synthesis.