Figure 8
Comparison of the active site entrances of BPDO-O B1 and NDO-O 9816-4 . Cartoon diagrams of the active site entrances for BPDO-OB1 (green) and NDO-O9816-4 (cyan). Multiple differences in the loop structure lead to a larger opening to the active site in BPDO-OB1. At position 1, the loop structure is pushed away from the entrance, compared to NDO-O9816-4. Position 2 shows the increased bulk of the Phe-224 side chain in the entrance opening, compared to the side chain of Leu-223 of BPDO-OB1. Finally, postion 3 shows a shift of the helix, which pulls the active site entrance open, compared to NDO-O9816-4. Biphenyl bound in the active site is shown in yellow and the mononuclear iron is shown as a rust-colored sphere. See Additional file 1, which shows these structures rotating in three dimensional space.