|
Figure 6.
Notch-FIH interactions.A, the FIH homodimer (molecule A
(pink) and molecule B (green)) in complex with N1-(1930–1949)
(yellow ball-and-stick representation bound to A, blue bound to
B) with the double-stranded β-helix core (blue in A and
raspberry in B) and Fe(II) (orange sphere). B, stereoview ribbon
representation of the
FIH·Fe(II)·2OG·N1-(1930–1949) dimer
structure complexed with the N1 peptide to 2.4 Å
resolution in yellow ball-and-stick representation and the σ[A]
weighted composite OMIT mF[o] - DF[c] difference electron
density contoured to 3σ (blue mesh) created by omitting the
Notch1 atoms from the calculation. Electron density was apparent
for residues 1936–1945 of the N1-(1930–1949) peptide (close
up view; supplemental Fig. S3). C, the FIH active site (FIH
(salmon with residues in white ball-and-stick representation),
2OG (green), N1-(1930–1949) (yellow), and Fe(II) (orange
sphere)). The pro-S C–H bond (gray) modeled at the Cβ
position of N1 Asn-1945 is positioned for oxidation. D,
ball-and-stick representation of the superimposed peptides when
bound to FIH. yellow, N1-(1930–1949); cyan, N1-(1997–2016);
white, HIF1αCAD. E, close up of superimposed structures:
FIH·N1-(1930–1949) (yellow),
FIH·N1-(1997–2016) (cyan), and FIH·HIF1αCAD
(white) showing the binding of the conserved leucine (N1
Leu-1937/2004 and HIF1αCAD Leu-795) in a hydrophobic pocket
(yellow-green surface) formed by residues from molecules A (dark
green) and B(orange) of the FIH dimer. F, superimposition of the
target Asn of N1-(1930–1949) when bound to FIH and the
equivalent Asn in the N1 ARD structure emphasizes the
conformational changes between them.
|
