Fig. 7

a Docking models of FeDFR1a and FeDFR2 in complexes with DHK, DHQ, and DHM substrate molecules calculated by AutoDock Vina. The DHK, DHQ, and DHM molecules are represented by ball-and-stick models with purple carbon atoms. The main chain structures of FeDFR1a and FeDFR2 are shown in white, and side chains of residues that interact with the ligands are shown as stick models with green carbon atoms. The amide nitrogen of Ala128 and the carbonyl oxygen of Glu226/227 are also shown. The alpha carbon of Gly136 in FeDFR2 is shown as a green sphere at the bottom right side of the image. The oxygen and nitrogen atoms are coloured red and blue, respectively. The NADP molecules are shown in the white CPK models. Hydrogen bonds are indicated as blue dotted lines. b Alternative model for FeDFR1a in complex with DHQ calculated by ASEDock. c Superposed substrates and side chains of Val/Phe133. Carbon atoms are coloured by complexes as follows: yellow; DHK-FeDFR1a, green; DHQ-FeDFR1a, magenta; DHM-FeDFR1a, orange; DHK-FeDFR2, cyan; DHQ-FeDFR2, white; DHM-FeDFR2