Nsp3 amino acid sequence variations. (A) Amino acids different from N. risticii Illinois, including insertions and deletions are divided by the number of sequences plotted for each amino acid position (# aa diffs). The horizontal axis displays Nsp3 amino acid positions (aa position) including the signal peptide and all detected amino acid insertions (264 aa total). SP, signal peptide. E, external loop; and TM, transmembrane domain are based on the predicted secondary structure. The number of sequences available at each amino acid position on Nsp3 (# seqs) is shown below. (B) Dendrograms of Nsp3 from the full-length protein, including the signal peptide (14 sequences total) and (C) the predicted external loop 2 (57 aa, including all insertions; 17 sequences total) are shown with bootstrap values greater than 50.0% for 1000 replicates. *, bootstrap value of 90.0% or greater. Post-2000 sequences are shown in the shaded area. GenBank accession numbers of new sequences are listed in Table 1.