Figure 5.
Replacing Tyr75 or His83 in the Y75 loop of HasAp with a noncoordinating Ala causes conformational changes in the His32 loop. Close-up views of the H32 (top) and Y75 (bottom) loops of H83A HasAp (cyan) and Y75A HasAp (green) superposed with the structure of wt HasAp (magenta).