FIGURE 5.

Structural models of 45L and S6 mutations in open and closed states. A, the structural models of V4830W in the open and closed states depict relative stabilization of the mutation in the open state due to formation of new van der Waals contacts. Residues forming contacts with residue 4830 are shown with surface representation, with the largest such interaction observed for V4830W in the open state. B, the structural models of G4834W in the open and closed states depict destabilization of the open state due to clashes between residue 4834 and residues in the S6 helix (shown as red dotted lines) and no such clashes in the closed state. C, the structural models of Q4947N show loss of van der Waals contacts between S6 and 45L due to a shortened side chain in the open state but no such loss in the closed state. The residues proximal to residue 4947 that can form contacts are shown with surface representation, and the atoms belonging to the side chain at residue 4947 are shown as spheres. All three mutants are compared with WT.