Fig. 7

Evolutionary and structural analyses of the MKK3 fused NTF2 domain. (a) Visual representation of distribution of NTF2 fusions across plants. (b )Multiple sequence alignment logo of the NTF2 domains found in all MAPKK3 shows conserved core structural aspartic and glutamic residues that have been shown to be essential for binging the RanGDP. (c) Three-dimensional structural model of the NTF2 domain of an Arabidopsis MKK3 At5G40440 (aa 366–516) modeled after the best structural match, S. cerevisiae NTF2-like domain Mex67:Mtr2 (PDB: 4WWU). Conservation profile across all plant NTF2 found in MKK3 is overlapped on the structure, with critical aspartic and glutamic residues depicted in yellow. (d) Maximum likelihood phylogeny of all Arabidopsis NTF2 domain-containing proteins (black nodes) and the NTF2 detected as fusions in all plants (red nodes). Distinct Arabidopsis NTF2 clades that form fusions are highlighted. The names of species are given as in Additional file 1. Each duplicate gene pair was assigned a color and a line on the right