DA and GDVII wt and mutant L protein sequences. (A) Sequences of DA and GDVII L proteins. The zinc (Zn) finger, acidic domain, and serine/threonine (Ser/Thr) domain are noted, and the locations of amino acids that vary between these two TMEV strains are highlighted. (B) The TMEV genome with a long 5′-untranslated region (5′-UTR) and coding regions for L and other viral proteins are shown. The L coding region was mutated in different ways to generate the selected plasmids and viruses that are shown. The three amino acid mutations in L of DALZn are shown with asterisks: a change of the cysteine to an arginine at amino acid 11, from the proline to a threonine at amino acid 12, and from the cysteine to an arginine at amino acid 14. The two amino acid mutations in L of GDVIILZn are shown with asterisks: a change of the cysteine at amino acid 3 to alanine and from histidine to leucine at amino acid 5. The open part of the rectangle corresponds to the DA L sequence, while the shaded part corresponds to the GDVII L sequence.