Fig. 3.

Dynamic domain motion in the structure of LTA₄H. (A) Closed conformation of LTA₄H with its FD in light blue and MD1 and MD2 in blue and teal, respectively. The same regions are colored pink, magenta, and hot pink for the open conformation. The hinge regions are in yellow. Zn²⁺ is in blue in the closed conformation and in magenta in the open conformation. (B) Y378 seals off the hydrophobic tunnel. Superposition of the active site and region of MD2 of closed D375N with bound LTA₄ (residues and Zn²⁺ are in blue, LTA₄ is in orange) onto open D375N (in pink) with blocked tunnel, and onto (C) open D375N (in magenta) with open tunnel.