Complexed Crystal Structure of Saccharomyces cerevisiae Dihydroorotase with Inhibitor 5-Fluoroorotate Reveals a New Binding Mode

Figure 2

Structure of ScDHOase complexed with 5-FOA. (a) Ribbon diagram of the ScDHOase-5-FOA complex tetramer. Each monomer is color-coded. Two zinc ions in the active site are presented as black spheres. (b) Structural comparison of the active sites in ScDHOase tetramer. The superimposed structures of these 5-FOA-bound states revealed that the flexible loop is in loop-in conformation in each subunit. (c) Stereo view of the real-space averaged OMIT |F_o| − |F_c| map (green mesh, contoured at 3σ) of 5-FOA bound to ScDHOase. The bound 5-FOA (cyan) and ScDHOase (light blue) are shown as sticks. The carboxylate group of 5-FOA ligates the Zn atoms (gray spheres). (d) The composite OMIT map (blue mesh, contoured at 1σ) of 5-FOA bound to ScDHOase. The bound 5-FOA (green) and ScDHOase (light blue) are shown as sticks. Two zinc atoms are shown as gray spheres.

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