Schematic representation of CaMV TAV protein functional domains.

<p>Numbers above the boxes indicate the amino acids and delimitate the functional domains of TAV: domain A (grey box, amino acids 1–116); MAV (light blue box, amino acids 117–242); RNA1 (dark blue box, amino acids 243–310); RNA2 domain (second dark blue box, amino acids 330–379), and the zinc finger (orange vertical bar, amino acids 446–462). Positions of the single NES and the two NLSs are indicated with red and black vertical bars, respectively [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0189062#pone.0189062.ref009" target="_blank">9</a>,<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0189062#pone.0189062.ref012" target="_blank">12</a>]. Below is detailed domain A with its subdomains, the conserved A1 region (amino acids 1–83) and the variable A2 region (amino acids 84–116) [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0189062#pone.0189062.ref009" target="_blank">9</a>]. The invariant sequence I1 is represented with a dark red box and its sequence is given with the EKI motif in red letters; the motif is substituted by three alanines (AAA) in TAVm3 mutant. The tandem repeated sequence EKI/LLM and the NES are underlined in red and black, respectively.