Fig. 1

Multiple sequence alignment of 3C proteases from various picornaviruses. a Alignment of DHAV and several other picornavirus amino acid sequences corresponding to the 3C protease. Invariant residues in the 3C protease are highlighted with a black background. The catalytic triad of the 3C protease is indicated with black arrows. The GxCG motif was conserved within these sequences, which may be part of the active site. b Phylogenic tree of the 3C proteases. The tree contains 80 sequences that correspond to 3C protein sequences from different single-stranded RNA viruses. Phylogenetic analysis was predicted with the maximum likelihood method. The background colors indicate that these 3C proteases were divided into six groups. The stability of the nodes was assessed with 1000 bootstrap replications, and bootstrap values above 0.5 were shown at the blue circles. The width of the blue circles represents the bootstrap value (range from 0.5 to 1)