Figure 3.
Fig. 3. Conformational changes in the NPR-C complex and the
molecular spring. (A) Backbone representations of bound (cyan)
versus unliganded (purple) NPR-C (the peptide in the middle is
shown in red). At the base of the structures, the width of the
gap separating the COOH-terminal domains of the dimer in bound
versus free form is indicated. The identical amino acid closest
to the COOH-terminal at the base of the gap (Ala^208) was used
in both structures as the point from which to measure the gap to
the dimeric-related residue (Ala^208*). For the elbow angle of
the structures, identical reference points (a vector defining an
helix in
the membrane-distal and -proximal domains) were chosen in bound
versus free structures from which to measure an interdomain
angle. (B) The spring tethering the membrane-distal and
-proximal domains in each monomer is stretched and lengthened by
2.5 Å in the bound structure (40). A ribbon representation
is shown of the linker peptide, along with the secondary
structure elements leading up to and away from the peptide. The
loose structure of the unbound peptide is obvious as compared
with the straightened peptide in the complex. (C) The N-linked
glycan at Asp248 forms extensive interactions with the linker
peptide, which are broken upon hormone binding and
conformational change (40). A stick representation of the
peptide, the N-linked glycan, and the surrounding amino acids is
shown. We have superimposed the Fo-Fc SIGMAA-weighted omit maps,
at 2.9 Å (left) and 2.0 Å (right) of the
NH[2]-linked glycan, to demonstrate the clarity of the
carbohydrate conformational change.
The above figure is reprinted
by permission from the AAAs:
Science
(2001,
293,
1657-1662)
copyright 2001.
helix in
the membrane-distal and -proximal domains) were chosen in bound
versus free structures from which to measure an interdomain
angle. (B) The spring tethering the membrane-distal and
-proximal domains in each monomer is stretched and lengthened by
2.5 Å in the bound structure (40). A ribbon representation
is shown of the linker peptide, along with the secondary
structure elements leading up to and away from the peptide. The
loose structure of the unbound peptide is obvious as compared
with the straightened peptide in the complex. (C) The N-linked
glycan at Asp248 forms extensive interactions with the linker
peptide, which are broken upon hormone binding and
conformational change (40). A stick representation of the
peptide, the N-linked glycan, and the surrounding amino acids is
shown. We have superimposed the Fo-Fc SIGMAA-weighted omit maps,
at 2.9 Å (left) and 2.0 Å (right) of the
NH[2]-linked glycan, to demonstrate the clarity of the
carbohydrate conformational change.