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Figure 3.
Figure 3: SRC-1 interactions with PPAR- bold gamma- .
a, A sigma-weighted 2 F [o]– F [c] omit electron-density
map is shown contoured at 1.0  for
the area surrounding the rosiglitazone ligand. b, A ribbons
drawing of the PPAR-  LBD
dimer and SRC-1, including the ligand rosiglitazone. The two
PPAR- monomers
are blue and green and the two SRC-1 interacting helices are
yellow. The structure of SRC-1 was determined from amino acids
628–640 and 684–703 and was crystallographically refined.
Very weak electron density from residues 670 to 684 was visible
but was not crystallographically refined and is shown as a
dashed line. SRC-1 amino acids 642–669 were disordered and not
structurally determined. The diagram shows how one SRC-1
molecule, with two interacting domains, forms a complex with a
PPAR- homodimer.
The dashed line connecting the two structurally determined
domains of SRC-1 is the proposed connection between these two
domains. c, The binding of SRC-1 (amino acids 628–642) to the
LXXLL-binding site of PPAR- .
SRC-1 is coloured: yellow, carbon; blue, nitrogen; red, oxygen.
The ribbon backbone of the PPAR- LBD
is in green. PPAR- amino
acids binding to the LXXLL helix are also shown in green. d,
Residues H631–T640 of SRC-1 are coloured as in c, with an
electrostatic surface of PPAR- showing
the coactivator-binding site. E471 and K301 side chains result
in the red (negative) and blue (positive) charges on the surface
of the coactivator-binding site at the N and C termini of the
SRC-1 helix, respectively. e, Residues H687–E696 of SRC-1 are
coloured as in c, with an electrostatic surface of PPAR- showing
the coactivator-binding site. f, Amino acids L465–K474 of the
PPAR- AF-2
helix of one monomer in the apo structure are shown in: green,
carbon; blue, nitrogen; red, oxygen, with an electrostatic
surface of PPAR- showing
the coactivator-binding site. E471 and K301 side chains result
in the red (negative) and blue (positive) charges on the surface
at the N and C terminus of the other PPAR- monomer.
This figure shows how one monomer in the apo crystal structure
orientates its AF-2 helix into the coactivator-binding site of
another crystallographically related monomer.
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