Molecular characterization of a foot-and-mouth disease virus containing a 57-nucleotide insertion in the 3'untranslated region.

A foot-and-mouth disease virus containing a 57-nucleotide (nt) insertion in the 3'untranslated region (3'UTR) was generated by transposon (tn)-mediated mutagenesis. Characterization of the mutant virus (A24-3'UTR8110) revealed no significant differences in virus growth, translation efficiency or virulence in cattle compared to the A24 wild-type virus. RNA modeling showed that the structures predicted in the 3'UTR were not affected by the tn insertion. These results revealed that the 3'UTR can tolerate foreign sequences that do not disrupt essential signals required for virus replication.