The relationship between P-loop and AAA+-specific structural components within the NSF–D2 hexamer (pdb: 1D2N). Images in the first to third rows correspond to (1) α,β-fold P-loop components (bluish gray), (2) AAA+-specific components (amino-terminal box II regions in red and carboxy-terminal box VII to sensor-2 regions in orange), and (3) all components. (The location of the box II element of NSF–D2 lacks strong statistical support and should be considered tentative.) Images in the first to third columns correspond to view (1) from the surface of NSF–D2 that faces the D1 domain, view (2) from the side, and view (3) from the carboxy-terminal surface. ATP is colored cyan. (See text for details.)
