FIGURE 1.

Conformational equilibrium of the nNOSr FMN subdomain. The diagram illustrates a two-state conformational equilibrium that may control the electron transfer reactions of the FMN subdomain (triangle). A connecting hinge links the FMN subdomain to the FNR subdomain (upper left). The FMN subdomain is expected to move back and forth to contact the FNR subdomain (Shielded) and an electron acceptor like cytochrome c (cyto c) or NOSoxy (Deshielded). The C-terminal tail (CT) is known to regulate the equilibrium by stabilizing the FMN-shielded conformation. This figure has been adapted from Ref. 27.