Figure 1

Structural overview of Pra Nsp (EU265817). Shaded rectangles and lines respectively represent gene exons and introns to scale. The signal peptide region is indicated by a blank box while the three domains are shaded to different degrees. Depicted are also the approximate annealing sites of the primer pairs used to amplify ~1 kb large segments of the gene and the corresponding names of the fragments. The two segments studied were Pra Nsp-D2 (in domain2) and Pra Nsp-D3 (in domain3). Dashes show approximate sites of amino acid substitutions located in the amplified coding regions as listed in Fig. 2. The approximate position of selected codons, both positive (black arrow heads with circles on their stems) and negative (open arrow heads), are indicated on exons, with codons listed in Table 4.