Nucleotide and amino acid compositions were determined using BioEdit Sequence Alignment Editorß v7.0.5.3. Picornavirus coding sequences (obtained from GenBank or picornaviridae.com) were determined by multiple alignments and subsequent truncations of the 59and 39UTRs. Discrepant nucleotides were substituted with the most frequently employed nucleotides, as determined by consensus alignment. Alignments available upon request. Predicted picornavirus cleavage sites were identified by amino acid sequence submission to the NetPicoRNA World Wide Web server [54] .