FIGURE 5.

Comparison of the molecular surfaces and lid loop over the active site cleft in the crystal structures of four GGTs. The lid loop is colored black, the catalytic threonine is shown as black sticks, and the glutamate is shown as spheres. A, EcGGT; B, HpGGT; C, BsGGT; D, hGGT1. In the top row of panels, the large subunit is colored dark gray, and the small unit is colored light gray. In the bottom row, the lid loop is colored black, and both subunits are colored light gray.