FIGURE 5.

CurM TE active site. A, surface of the active site cleft. In the molecular surface view, the active site (magenta catalytic triad) is in a cleft in which the presumed phosphopantetheine entrance is lined with conserved residues (cyan), with other parts of the protein surface in green and the modeled acyl-enzyme intermediate in gray sticks. B, modeled acyl-enzyme intermediate (gray C). In this stereo view, the intermediate is surrounded by conserved amino acid residues (cyan C) and the catalytic triad (Ser¹⁰⁰, Glu¹²⁴, and His²⁶⁶) (magenta C). The carbonyl oxygen is bound in the oxyanion hole (hydrogen bonds to the NHs of the Ile³² and Met¹⁰¹).