Figure 3.

Structure of the active site of Shewanella oneidensis MR-2 UP in complex with uridine and sulfate (PDB 4R2W). The nitrogen, oxygen, and sulfur atoms are shown in blue, red, and yellow, respectively. The carbon atoms of the protein and the substrate are green and violet, respectively. The atoms of the adjacent subunit of the UP dimer are colored in grey. The hydrogen bonds involving the uridine molecule and sulfate are indicated by dashed lines.