FIGURE 6.

The models of the E. coli MscL in the open and closed conformations shown with solvent-accessible surfaces. The positions of the transmembrane helices forming the barrel correspond to conformations 2 (closed) and 11 (open) from Sukharev et al. (2001b), whereas the bundle-like arrangement of the C-terminal segments in the open state is taken from Anishkin et al. (2003). The cross-section planes are positioned approximately at the boundaries of the hydrophobic core of the membrane (±12.5 A along the z axis). The average cross-sectional areas of the modeled closed and open states are 17.5 and 40.8 nm², respectively, predicting the transition-related area change of 23.3 nm².