Figure 2.
Fig. 2. Contributions of individual atom types to the
resolution-dependent electron density profile in the central
cavity of the FeMo-cofactor. Six iron atoms and all nine of the
cluster's sulfur atoms are located on two concentric spheres.
Having identical distances from the center (3.3 Å for
sulfur, 2.0 Å for iron), they are the main contributors to
the electron density profile there. The apical iron and
molybdenum atoms exert only a minor influence. Plots of (r) versus
d[max], calculated analogously to Fig. 1 (inset), illustrate
this effect. The curves for six iron atoms at 2.0 Å
(blue), nine sulfur atoms at 3.3 Å (dark yellow), and one
apical iron (Fe1, gray) and the molybdenum (orange) at 3.5
Å are shown. The sum of of all these contributions is
shown in black.
The above figure is reprinted
by permission from the AAAs:
Science
(2002,
297,
1696-1700)
copyright 2002.
(r) versus
d[max], calculated analogously to Fig. 1 (inset), illustrate
this effect. The curves for six iron atoms at 2.0 Å
(blue), nine sulfur atoms at 3.3 Å (dark yellow), and one
apical iron (Fe1, gray) and the molybdenum (orange) at 3.5
Å are shown. The sum of of all these contributions is
shown in black.