|
Figure 3.
Figure 3: ADP serves as an organizing centre for the adjoining
three domains and locks Apaf-1 in an inactive conformation.
a, ADP is deeply buried and inaccessible to even small molecules
unless the surrounding domains undergo conformational changes.
Left, a cross-section of Apaf-1, with its van der Waals surface
represented by a colour-coded mesh. Right, the CARD domain
(green) blocks the only solvent channel to the ADP-binding
pocket. b, A stereo representation of the coordination of ADP by
residues from three domains. As in other AAA + ATPases16, ADP is
bound primarily in the hinge region between the  /
 fold
(blue) and helical domain I (cyan). In Apaf-1, the winged-helix
domain also contributes a direct hydrogen bond (from His 438) to
the -phosphate
group and a water-mediated hydrogen bond (from Ser 422) to the
ribose.
|
