Figure 2.
FIGURE 2. Ribbon representation of ligand-free PikC. A,
open, and B, closed conformations of ligand-free PikC (2BVJ). C,
overlay of both conformations, open (cyan) and closed (gray),
demonstrating that in the open form, the F and G helix are bent
away from the heme to enable substrate access to the active
site. Molecules in C are rotated 90° toward the viewer
along a horizontal axis in the plane of drawing when compared
with A and B. The F helix is not seen in this orientation.
Closed conformation is related within r.m.s. deviations of 0.58
Å for C atoms to catalytically
relevant YC-17- and narbomycin-bound forms. The heme co-factor
is shown in red.
90° toward the viewer
along a horizontal axis in the plane of drawing when compared
with A and B. The F helix is not seen in this orientation.
Closed conformation is related within r.m.s. deviations of 0.58
Å for C 
atoms to catalytically
relevant YC-17- and narbomycin-bound forms. The heme co-factor
is shown in red.