Figure 5.

Configuration of ionic-lock and Y288 associated with water flux gating. (A) Time traces probing the dynamics of three major structural motifs, i.e., ionic-lock (DRY motif), W246^6.48 of CWxP, and Y288^7.53 of NPxxY. From the top shown are the distances between R102^3.50 and E228^6.30 (ionic-lock), and between R102^3.50 and Y288^7.53, and the dihedral angles of W246^6.48 and Y288^7.53 for the apo (black), agonist-bound (red), and antagonist-bound (blue) forms. The histograms on the right are drawn using data with t > 400 ns. (B) The configurations of R102^3.50, E228^6.30, and Y288^7.53 in the inactive and active states. The ionic lock (R102-E228) in the inactive form is disrupted in the active form, allowing R102 to form a contact with Y288. The passage of water from the IC domain is blocked by this change in the active form. The helix 7 is illustrated with the transparent band in purple. To see this figure in color, go online.