Figure 1 - full size

 

Figure 1.
Figure 1. A schematic depicting the closed and open states of an active site of rubisco. The view is looking from above the central axis of the a/b barrel. The N-terminal domain (N terminus to residue 150) from the L[2] partner large subunit covers most of the top of the barrel. A distinct C-terminal domain exists as an appendage of the barrel domain. Two small subunits make separate contacts with the domains that form the single active site. With respect to the closed state, the N-terminal domain in the open state has moved left and correspondingly one small subunit moves up and to the left. On opening, Loop 6 of the barrel domain retracts to extend helix 6 in a stable configuration and the C-terminal strand pulls away from the active site and the barrel domain and is usually disordered in the open state crystal structures. In the closed state, there is no solvent access to the substrate and substrate binding can be divided into three distinct zones; the P1-binding site, the P2-binding site and the metal site.

The above figure is reprinted by permission from Elsevier: J Mol Biol (2000, 298, 903-916) copyright 2000.