Fig. 3.

Conserved features of MYB-like domain through TRB lineages. (A) Consensus sequences of Myb-like domain in each evolutionary lineage were visualised using sequence logos. Colored squares, represent TRB1-5 proteins from A. thaliana; Inverted triangle, the aa at position 3 (B) at N-terminus of TRBs that is replaced in Dicots from TRB_B lineage to N; Asterisk, the aa at position 5 (K) that mediates intermolecular contacts between telomeric DNA and N-terminus of all TRBs (Fig. 1C); Circle, the negatively charged aa (E/D) at position 11 conserved across all TRB lineages; Rhombus, the aa at position 14 replaced from uncharged (A/S) to negatively charged (E/D) in the whole TRB_B lineage; Trapezoid, the aa at position 17 that is in Dicots from TRB_B lineage partially replaced from positively charged (K/R) to hydrophobic (L); Triangle, the aa at position 60 that shows lower conservation in Dicots from TRB_B lineage than in other lineages. (C) The representative members of Dicots from TRB_B, TRB_C and TRB_D lineages, namely A. thaliana TRB4, TRB1 and TRB2, respectively, were analyzed. The three-dimensional model of the Myb-like domains from the site opposing the DNA-binding viewpoints are based on the hTRF2-DNA interaction model (PDB: 1WOU) (Court et al. 2005). The evolutionary dynamics of aa substitutions among aa residues within Myb-domain of these exemplified were visualized using ConSurf 2016 (Ashkenazy et al. 2016). The conservation of residues is presented in a scale, where the most conserved residues are shown in dark magenta and non-conserved residues as white. (D) Surface models showing the charge on the Myb-like domain are presented from the site opposing the DNA-binding viewpoint for each model. Residue charges are coded as red for negative, blue for positive, and white for neutral, visualised using PyMol, Version 2.4.1, Schrödinger, LLC