FIGURE 4.

Conformational changes of RedJ. A, front view of the Ppant channel and active site cavity (view similar to Fig. 3C). In the ribbon diagram at the top left, RedJ in the open entrance conformation (cyan lid, orange core) is superimposed on the closed entrance form (green lid, orange core). Open entrance (left center) and closed entrance (left bottom) forms are shown separately with the molecular surfaces. The images are cut away to illustrate the Ppant cleft. A white and red rod mimics the Ppant arm of the substrate, and the catalytic serine is in magenta. The Ppant cleft leading to the catalytic serine is closed only at its entrance in the bottom image. B, side view into the Ppant entrance. Images are rendered as in A with full molecular surfaces in the center and bottom images.