FIGURE 5.

Structure of YlxQ. (A) Cartoon representation of the overall structure of YlxQ, with secondary structure elements labeled as in Figure 1A. (B) Portion of the 1.55 Å resolution anneal-omit 2|F_o| − |F_c| electron density map corresponding to the α4–β4 loop of YlxQ (outlined in panel A) is shown contoured at 2.5σ. The corresponding α4–β4 loop from L7Ae (only main chain atoms) is shown in gray for comparison. C_α atoms are shown as enlarged spheres to highlight the main chain trajectories of YlxQ and L7Ae. (C) Structural alignment of YlxQ (blue) and YbxF (red) and (D) of YlxQ (blue) and L7Ae (gray).