Figure 1

Omit-map showing the electron density corresponding to the two partners of the [UOX/UA/CN] complex, the cyanide and uric acid. The active site is delimited by 1) the conserved residues implicated in the molecular tweezers (Arg 176, Glu 228) that holds the substrate, 2) the Phe 159 closing one end of the cavity below, and 3) the two Asn 254 and Thr 57* forming another tweezers above the mean plane of the ligand that construct a location where efficient electron transfer can take place at a low energy level via the catalytic triad Thr 57* Lys 10* His 256, and the associated water molecules shown in Figure 3). The orientation of cyanide is based on a coherent evolution of the C/N thermal factors during refinements, compared to neighboring atoms (stereo view).