Fig. 5: Movements of helix α1, α2, and α4 in the unbound and ligand-bound MDD_EF.

a Locations of helix α1 (left), α2 (middle), and α4 (right) in MDD_EF. b Positions of helix α1 and key residues (Q68 and K71) in four different structures (left: apo-MDD_EF, gray, state I; middle-left: MDD_EF-MVAPP, cyan, state II; middle-right: MDD_EF-MVAPP-AMPPCP-Mg²⁺, magenta, state III; right: MDD_EF-MVAPP-ADPBeF₃-Mg²⁺, blue, state IV). The binding sites of MVAPP (1) and ATP (2) are circled with dashed lines. The center of helix α1 is shown as a rod colored in red (N terminus) and green (C terminus). Magnesium ions and water molecules are shown as green and red spheres, respectively. c Position of helix α2 and key residues (S106) in four different structures as described in b. d Position of helix α4 and key residues (S191) in four different structures as described in b. K187 in the β10-α4 loop (right panel) is shown as a stick model. e Superposition of helix α1 (left), α2 (middle), and α4 (right) from four different structures. The helical movements of α1, α2, and α4 upon substrate binding are drawn in black lines. The key residues, S106 and S191, in the middle and right panels are shown in stick and the side-chain movements are drawn in red lines.