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Figure 6.
Fig. 6. Proposed structural rearrangements in the
proximity of the steroid-binding site of human SHBG in the
presence (A) and absence (B) of Zn2+ in metal-binding site II.
The model of the unoccupied metal-binding site II (B) is based
on a subtraction of the unambiguous conformations observed for
Asp65 and His83 in the presence of zinc (A) from the alternative
conformations of these residues observed when metal-binding site
II was partially occupied (see Fig. 2B). Note that neither the
crystallographic analysis nor the hydrogen bonding network in
which Asn82 participates allow us to distinguish whether its
nitrogen or oxygen atom points toward the steroid 17  -hydroxy
group.
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