3D structure alignment (3D-SA) and alignment mapping on 3D structure (AM-3D) of eukaryote TLPs. Amino acids of the REDDD and FF motifs are represented with side-chains in balls and sticks. Color code of side-chains, red: negatively charged; blue: positively charged; yellow: hydrophobic. White dashed-lines indicate acidic cleft limits. (A), 3D-SA of tobacco PR-5d and cherry Pru av 2. Protein backbone color code, red: identical amino acids; blue: different amino acids; grey: unaligned residues, green: glycine/phenylalanine residues discussed in the text. Disulfide bonds are in orange. (B), AM-3D of 9 subgroup I TLPs using the PR-5d structure as template. The four-color code of the protein backbone (from red to blue) corresponds to a decrease in amino acid conservation. (C), AM-3D of 15 subgroup II TLPs using the Pru Av 2 structure as template. Color code and annotations are as in B. Amino acids under diversifying selection  are indicated by white asterisks. (D, E and F), Highlights of β-sheets forming the acidic cleft in A, B and C respectively. Color code is similar to that in A, B and C. In D, the residues forming the REDDD and FF motifs are numbered as in Figure 4. White arrows indicate motif differences discussed in the text. (G), AM-3D of the 9 small-TLPs indicated in Additional file 7 using the TLX1 structure as template. Color code is similar to that in B. A white dashed ellipse marks the missing acidic cleft.