Fig. 4

Three-dimensional structure of B. distachyon ARF protein BdARF1. a. Schematic diagram of 3D structure of BdARF1. b Schematic diagram of 3D structure of BdARF1. It is obtained by (a) rotating 180 degrees clockwise and then 90 degrees upward. c Surface representation of BdARF1 corresponding to (a). d Surface representation of BdARF1 corresponding to (b). The precise positions of six critical amino acids were identified among Type I and Type II functional divergence and positive selection in the 3D structure. Five unique amino acid sites are shown on the surface of the 3D structure. In the figure, helix is represented by light blue, purple represents sheet, pink represents loop, and the six key amino acid positions are indicated by green. The amino acids represented by the six key positions and their positions in the protein sequence are labeled