Figure 4.

Comparison of ligand binding site in ArnB and PseC. Stereo representation of the active site of ArnB (subunits colored yellow and cyan) superimposed on PseC (subunits colored light orange and slate blue). The position and conformation of the ArnB and PseC ligands, UDP-Ara4N and UDP-4-amino-4,6-dideoxy-AltNAc, respectively, are very similar. Carbon atoms in the ArnB and PseC ligands are colored green and pink, respectively, whereas oxygen is red, nitrogen is blue, and phosphorus is orange.