Fig. 3: Conformational comparison in different stages of catalysis.

a Overall structural comparison of Dat. Left, superimposition of apo-Dat (red, PDB code: 3V8I) and Dat/Ac-CoA complex (blue, PDB code: 3TE4); right, superimposition of Dat/Ac-CoA complex (blue, PDB code: 3TE4), Dat/Ac-CoA/tryptophol complex (gray, PDB code: 6K80), and Dat/CoA/Ac-TRYP complex (orange, PDB code: 5GI9). Conformational changes are shown by arrows. b Cofactor-binding pocket showed an open-to-closed form conversion from apo-Dat (red) to Dat/Ac-CoA complex (blue), forming salt bridges in α1/α5/α7 region. c Superimposition of apo-Dat (red) and Dat/Ac-CoA complex (blue) focusing on catalytic site. Two hydrogen bonds between α7 and α9 were established by His220, Ser183, and His184 after Ac-CoA binding. The orientations of catalytic residues, Glu47, Ser182, and Ser186 also changed. d The reaction tunnels in the apo-Dat, binary complex, and two ternary complexes are shown in gray. A bottleneck surrounded by Met121 and Asp142 was formed after Ac-CoA binding. e Superimposition of apo-Dat (red) and Dat/Ac-CoA complex (blue) focusing on aromatic residues of the substrate-binding pocket. Residues, substrates, and cofactors are shown as sticks. Distances, salt-bridge interactions, hydrogen bonds, and Met-aromatic interactions are shown by dashed lines.