We identified 10 protease sites (data not shown) dividing the HRV A2 polyproteins into four structural and seven nonstructural proteins ( Figure 1A ). However, unlike previous studies that relied on amino acid alignments to determine cleavage sites [33] , we obtained additional evidence that these sites were recognised by 2A pro and 3C pro by using a neural network protease cleavage-site prediction tool. A single cleavage by 2A pro was predicted between an A or L and a G residue at the VP1/2A junction. The remaining cleavages, predominantly occurring between Q and G residues, were mediated by 3C pro . Three motifs crucial for RNA polymerase binding (YGDD, TFLKR and SIRWT) were identified in all HRV A2 sequences [35, 36] .